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Studies have shown that the high expression of EphA4 in gastric cancer tissues may correlate with unfavorable clinical pathological characteristics. Therefore, EphA4 may be an effective target for treating gastric cancer in addition to HER-2/neu. In this study, generated scFv S3 can bind endogenous EphA4 of gastric cancer cells and has significant membrane staining. Additionally, scFv S3 binding to EphA4 inhibits the growth and migration of cancer cells and the growth induction that ephrinA1 generates in gastric cancer cells. We found that EphA4 molecules may degrade through antibody treatment of cells, and the increase in LAMP1 and LAMP2 indicates that lysosome is involved in the degradation. The scFv S3 administration leads to the signals pAKT, pERK, and pSTAT3 decrease in cancer cells. The xenograft model of HER-2/neu low expressing gastric cancer cell SNU-16 exhibits better therapeutic effects by scFv S3 than trastuzumab scFv. The scFv S3 administration in vivo can degrade EphA4 molecules in tumor tissues, decreasing Ki67 and increasing cleaved C3 molecule expression. Furthermore, we identified and validated that scFv S3 generates essential ionic bonding with R162 on EphA4. The antibody may provide effective treatment for patients with gastric cancer and abnormal activation or overexpression of EphA4 signaling. • EphA4 may be an effective target for the clinical treatment of gastric cancer. • The anti-EphA4 antibodies have neutralizing effects against gastric tumor growth. • The R162 on EphA4 is the key residue that affected the antibody response. [ABSTRACT FROM AUTHOR]

One-carbon metabolism is essential for our human cells to carry out nucleotide synthesis, methylation, and reductive metabolism through one-carbon units, and these pathways ensure the high proliferation rate of cancer cells. Serine hydroxymethyltransferase 2 (SHMT2) is a key enzyme in one-carbon metabolism. This enzyme can convert serine into a one-carbon unit bound to tetrahydrofolate and glycine, ultimately supporting the synthesis of thymidine and purines and promoting the growth of cancer cells. Due to SHMT2's crucial role in the one-carbon cycle, it is ubiquitous in human cells and even in all organisms and highly conserved. Here, we summarize the impact of SHMT2 on the progression of various cancers to highlight its potential use in the development of cancer treatments. • SHMT2 is a relatively novel research goal in recent years. • SHMT2 is a key enzyme in one-carbon metabolism. • SHMT2 potential use in the development of cancer treatments. • This study aims to understand the progression of various cancers and explore long-term treatment options. [ABSTRACT FROM AUTHOR]

Nucleus accumbens-associated 1 (NAC1) is a member of pox virus and zinc finger/bric-a-brac tramtrack broad complex (BTB/POZ) gene family. Overexpression of NAC1 is implicated in cancer development, recurrence and chemotherapy resistance. In our previous study, we found NAC1 was a potential small ubiquitin-like modifier (SUMO) substrate in prostate cancer cells. However, there was still lack of evidences to further support and validate the result. In this work, we found that NAC1 is a multi-SUMO-sites acceptor. The SUMO acceptor lysines were K167, K318, K368, K483 and K498. SUMOylation didn't alter the localization of NAC1, but facilitated the formation of NAC1 nuclear bodies. Compared with NAC1 wild type (NAC1 WT), the SUMO-sites mutant of NAC1 (NAC1 SM) suppressed cell proliferation and tumor growth in cellular and animal levels. This work uncovered the function of SUMOylation of NAC1 in prostate cancer cells. • NAC1 is a multi-SUMO-sites acceptor. • The SUMOylation of NAC1 facilitates the formation of NAC1 nuclear bodies. • The SUMOylation of NAC1 affects the growth of prostate cancer cells. [ABSTRACT FROM AUTHOR]

Cervical cancer is one of the most lethal gynaecological malignancies in females. The deubiquitylase UCHL3 has been studied as an oncogenic factor in multiple cancers. However, the expression pattern and function profile of UCHL3 in cervical cancer hasn't been fully characterized. Here, we revealed that UCHL3 was highly expressed in cervical cancer and overexpressed UCHL3 predicted a poor survival probability in cervical cancer patients. Our findings showed that knockdown of UCHL3 inhibited cell growth, migration and invasion in cervical cancer cells while UCHL3 knockdown inhibited cervical cancer development and metastasis in vivo in mouse models. Mechanistically, co-immunoprecipitation assay showed that UCHL3 directly interacted with NRF2. Knockdown of UCHL3 decreased NRF2 expression while overexpression of UCHL3 stabilized NRF2 via deubiquitination. In addition, overexpression of UCHL3 with C92A mutation didn't affect NRF2 stability. Moreover, we revealed that overexpression of NRF2 could antagonize the function of UCHL3 knockdown in cervical cancer cells. Collectively, our findings suggest that UCHL3 promotes cervical cancer development and metastasis by stabilizing NRF2 via deubiquitination. Thus, UCHL3/NRF2 axis could be utilized to develop efficient treatments for cervical cancer patients. • UCHL3 is highly expressed in cervical cancer and predicts poor survival. • Knockdown of UCHL3 suppresses cervical cancer cell growth and invasion. • UCHL3 interacts with NRF2 and stabilizes NRF2 via deubiquitination. [ABSTRACT FROM AUTHOR]

Breast cancer is malignant cancer that severely threatens the life quality of female patients. N6-methyladenosine (m6A) is a prevalent modification of RNA. METTL16 is an important methyltransferase. This work aims to study the role of METTL16 in breast cancer cell death. The expression of METTL16 in clinical breast cancer specimens was analyzed by qPCR assay. The in vitro and in vivo breast cancer cell proliferation was measured by CCK8, colony formation, and xenograft mouse model. Cell ferroptosis was assessed by measuring the accumulation of iron, Fe2+, and lipid ROS. The mechanistic study was performed by RNA degradation, qPCR, and Western blotting assay. METTL16 was overexpressed in tumor tissues from breast cancer patients compared with the para-tumor tissues. Knockdown of METTL16 suppressed in vitro cell proliferation and in vivo tumor growth of breast cancer cells. Meanwhile, METTL16 silencing led to elevated intracellular levels of iron, Fe2+, and lipid ROS, indicating the incidence of ferroptosis. Furthermore, siMETTL16 decreased m6A methylation and enhanced the degradation of GPX4 RNA. METTL16-regulated m6A methylation of GPX4 stimulates proliferation and suppresses ferroptosis of breast cancer cells. Therefore, we concluded that METTL16 epigenetically enhanced GPX4 expression via m6A modification to promote breast cancer progression by inhibiting ferroptosis. • METTL16 is upregulated in breast cancer and promote cancer cell growth. • Silencing of METTL16 triggers breast cancer cell ferroptosis. • Silencing of METTL16 inhibits breast cancer growth in vivo. • METTL16 modulates breast cancer cell ferroptosis via m6A modification of GPX4. • Overexpression of GPX4 abolishes METTL16 depletion-induced ferroptosis. [ABSTRACT FROM AUTHOR]

This study aimed to determine the role of COL17A1 in tumor progression and predict the prognosis of pancreatic cancer (PC). RNA-seq data from The Cancer Genome Atlas and Genotype-Tissue Expression were analyzed using bioinformatics methods. "Limma" package was used to screen differentially expressed genes (DEGs). Prognostic-associated data were further analyzed using univariate Cox regression and verified using the GSE28375 and GSE62452 datasets. Protein-protein interaction (PPI) network analysis was integrated to screen for hub genes. In vitro quantitative real-time PCR (qPCR) and western blotting were used to detect gene expression. The functional attributes of PC cells were verified by wound healing assays, migration and invasion assays, Cell Counting Kit 8 (CCK8), and 5-ethynyl-2′-deoxyuridine (EdU) assay. On analyzing PC data, 4637 DEGs were identified. Of these, 2399 genes were upregulated and 2238 were downregulated. Through PPI network analysis, we identified that COL17A1 expression was highly correlated with poor prognosis of patients with PC. Functional attribute assays in the in vitro study showed that COL17A1 knockdown inhibited PC cell proliferation, migration, and invasion. According to our results, COL17A1 promotes PC cell proliferation, migration, and invasion mediated by the epithelial-mesenchymal transition (EMT) pathway. Thus, COL17A1 could be used as a prognostic marker in PC. • COL17A1 has higher expression levels in pancreatic cancer tissue than normal pancreatic tissue. • COL17A1 significantly promotes pancreatic cancer cells growth, migration and invasion via regulating EMT pathways. • COL17A1 is a valuable indicator to assess prognosis, and providedes a promising therapeutic target for pancreatic cancer. [ABSTRACT FROM AUTHOR]

Anti-diabetic drug, metformin, has attracted attentions as an anti-cancer agent due to the suppression of mTORC1 as a master switch of cell growth in various cancers. Upon mTORC1 inhibition, translation of proteins possessing IRES elements in their mRNAs still occurs in order to maintain proper cell function. Thus, inhibitor of apoptosis proteins are expected to be upregulated by mTORC1 inhibition due to the possession of IRES elements. Surprisingly, however, inhibition of mTORC1 with metformin in breast cancer cell lines of MDA-MB-231 and MCF-7, caused the downregulation of IRES-element possessing proteins of cIAP1, XIAP and Bcl-2, 24 h post-treatment. Interestingly, a shorter treatment time of 8 h, however, was accompanied by increased expression of these proteins. Importantly, inclusion of the proteasome inhibitor, Bortezomib, caused the upregulation of the tested anti-apoptotic proteins in both cell lines. These observations suggest that mTORC1 inhibition has a bifold effect; first upregulation of IRES-dependent survival proteins to prevent untimely cell death followed by an opposite effect, which is the enhanced proteosomal degradation of these protein in order to maintain a balanced response. • Metformin mediated mTORC1 inhibition enhances IRES-dependent translation of antiapoptotic proteins. • This effect on ani-apoptotic proteins is countered by enhanced proteosomal degradation, also mediated by mTORC1 inhibition. • mTORC1 inhibition upregulated anti-apoptotic proteins to prevent untimely cell death. • Proteasome constantly degrades anti apoptosis proteins to keep a balanced response. [ABSTRACT FROM AUTHOR]

Gastric cancer is a one of the most common malignant tumors with poor prognosis worldwide. Leucine-rich G-protein-coupled receptor 5 (LGR5) is determined as a modulator of Wnt signaling cascade and R-spondins are a family of secretory agonists in the Wnt signaling and act as ligands to interact with LGR5. However, the function of Rspondin-1 in GC remains obscure. Here, we identified the effect of Rspondin-1 on GC progression. Rspondin-1 and LGR5 were upregulated in clinical gastric cancer tissues. CCK-8 assay revealed that the viability of GC cells was reduced by Rspondin-1 depletion and enhanced by Rspondin-1 overexpression. The depletion of Rspondin-1 decreased while the overexpression of Rspondin-1 increased the numbers of colony formation and Edu-positive GC cells. The depletion of Rspondin-1 attenuated the invasion and migration ability of GC cells. Moreover, sphere formation assays revealed that the knockdown of Rspondin-1 reduced the stemness of GC cells. The expression of cancer stem cell markers, including Nanog, OCT3/4, and SOX2 were suppressed by Rspondin-1 depletion in GC cells. Rspondin-1 induced tumor growth of gastric cancer cells in vivo. Mechanically, the cell viability and invasion suppressed by the depletion of Rspondin-1 in GC cells were rescued by LGR5 overexpression. Besides, the overexpression of LGR5 reversed Rspondin-1 knockdown-inhibited Nanog and OCT3/4 expression. Consequently, we concluded that Rspondin-1 contributes to the progression and stemness of gastric cancer by LGR5. • Rspondin-1 and LGR5 are upregulated in clinical gastric cancer tissues. • Rspondin-1 contributes to proliferation of gastric cancer cells in vitro. • Rspondin-1 promotes migration and invasion of gastric cancer cells in vitro. • Rspondin-1 enhances cancer stem cell properties of gastric cancer cells in vitro. • Rspondin-1 induces tumor growth of gastric cancer cells in vivo • Rspondin-1 contributes to progression of gastric cancer by LGR5. [ABSTRACT FROM AUTHOR]

Casein kinase 1α (CK1α) is a serine/threonine protein kinase that acts in various cellular processes affecting cell division and signal transduction. CK1α is present as multiple splice variants that are distinguished by the presence or absence of a long insert (L-insert) and a short carboxyl-terminal insert (S-insert). When overexpressed, zebrafish CK1α splice variants exhibit different biological properties, such as subcellular localization and catalytic activity. However, whether endogenous, alternatively spliced CK1α gene products also differ in their biological functions has yet to be elucidated. Here, we identify a panel of splice variant specific CK1α antibodies and use them to show that four CK1α splice variants are expressed in mammals. We subsequently show that the relative abundance of CK1α splice variants varies across distinct mouse tissues and between various cancer cell lines. Furthermore, we identify pathways whose expression is noticeably altered in cell lines enriched with select splice variants of CK1α. Finally, we show that the S-insert of CK1α promotes the growth of HCT 116 cells as cells engineered to lack the S-insert display decreased cell growth. Together, we provide tools and methods to identify individual CK1α splice variants, which we use to begin to uncover the differential biological properties driven by specific splice variants of mammalian CK1α. • CK1α splice variant abundance varies across normal tissues and cancer cell lines. • Cancer cell lines with high levels of select CK1α splice variants express distinct biological pathways. • The S-insert of CK1α promotes cell growth in a cancer cell line. [ABSTRACT FROM AUTHOR]

The role of extracellular matrix (ECM) prevalent in the brain metastatic breast cancer (BMBC) niche in mediating cancer cell growth, survival, and response to therapeutic agents is not well understood. Emerging evidence suggests a vital role of ECM of the primary breast tumor microenvironment (TME) in tumor progression and survival. Possibly, the BMBC cells are also similarly influenced by the ECM of the metastatic niche; therefore, understanding the effect of the metastatic ECM on BMBC cells is imperative. Herein, we assessed the impact of various ECM components (i.e., Tenascin C, Laminin I, Collagen I, Collagen IV, and Fibronectin) on brain metastatic human epidermal growth factor receptor 2 (HER2)-positive and triple negative breast cancer (TNBC) cell lines in vitro. The highly aggressive TNBC cell line was minimally affected by ECM components exhibiting no remarkable changes in viability and morphology. On the contrary, amongst various ECM components tested, the HER2-positive cell line was significantly affected by Laminin I with higher viability and demonstrated a distinct spread morphology. In addition, HER2-positive BMBC cells exhibited resistance to Lapatinib in presence of Laminin I. Mechanistically, Laminin I-induced resistance to Lapatinib was mediated in part by phosphorylation of Erk 1/2 and elevated levels of Vimentin. Laminin I also significantly enhanced the migratory potential and replicative viability of HER2-positive BMBC cells. In sum, our findings show that presence of Laminin I in the TME of BMBC cells imparts resistance to targeted therapeutic agent Lapatinib, while increasing the possibility of its dispersal and clonogenic survival. [Display omitted] • HER2+ brain metastatic brain cancer cells are responsive to Laminin I. • Laminin I confer resistance to HER2+ BT474Br3 cells against Lapatinib. • Erk 1/2 is involved in Laminin I mediated Lapatinib resistance in BT474Br3 cells. • Laminin I enhances Lapatinib mediated Vimentin expression in BT474Br3 cells. • Migration and clonogenic survival of BT474Br3 cells are augmented by Laminin I. [ABSTRACT FROM AUTHOR]

In recent years, cancer metabolism has attracted attention as a therapeutic target, and glutamine metabolism is considered one of the most important metabolic processes in cancer. Solute carrier family 1 member 5 (SLC1A5) is a sodium channel that functions as a glutamine transporter. In various cancer types, SLC1A5 gene expression is enhanced, and cancer cell growth is suppressed by inhibition of SLC1A5. However, the involvement of SLC1A5 in clear cell renal cell carcinoma (ccRCC) is unclear. Therefore, in this study, we evaluated the clinical importance of SLC1A5 in ccRCC using The Cancer Genome Atlas database. Our findings confirmed that SLC1A5 was a prognosis factor for poor survival in ccRCC. Furthermore, loss-of-function assays using small interfering RNAs or an SLC1A5 inhibitor (V9302) in human ccRCC cell lines (A498 and Caki1) showed that inhibition of SLC1A5 significantly suppressed tumor growth, invasion, and migration. Additionally, inhibition of SLC1A5 by V9302 in vivo significantly suppressed tumor growth, and the antitumor effects of SLC1A5 inhibition were related to cellular senescence. Our findings may improve our understanding of ccRCC and the development of new treatment strategies for ccRCC. • Solute carrier family 1 member 5 (SLC1A5) is a prognostic factor for poor survival in ccRCC. • SLC1A5 -KO suppressed ccRCC cell proliferation, migration, and invasion in vitro • Inhibition of SLC1A5 had antitumor effects in vitro and in vivo. • SLC1A5 inhibition increased ROS levels and induced cellular senescence. [ABSTRACT FROM AUTHOR]

Sialylation, the final stage of post-translational modification of proteins, is achieved in the Golgi apparatus and is related to the malignant phenotype of cancer. Disialylation of ganglioside (GD3) by St8sia1 and polysialylation by St8sia2 and 4 have been shown to be related to malignant phenotypes; however, di/oligosialylation by St8sia6 is still unknown. In this study, we analyzed the malignant phenotype of St8sia6 and found that upregulation of St8sia6 in melanoma B16 cells increased anchorage-independent cell growth, which was not due to sialic acid cleavage by a sialidase. Moreover, unlike other sialyltransferases, St8sia6 localized to the endoplasmic reticulum (ER). We found that the localization to the Golgi apparatus could be regulated by swapping experiments using St8sia2; however, the malignant phenotype did not change. These data demonstrate that the enhancement of anchorage-independent cell growth by St8sia6 is not due to its localization of ER, but is due to the expression of the protein itself. • The expression of α2,8-sialyltransferase 6, St8sia6, showed a malignant phenotype in B16 mouse melanoma cells. • Unlike other glycosyltransferases and sialyltransferases, St8sia6 localized in the ER. • Abnormal ER-localization of St8sia6 was not responsible for the malignant phenotype of B16 cells. [ABSTRACT FROM AUTHOR]

Histone modification is the key epigenetic mechanism that regulates gene expression. Coactivator-associated arginine methyltransferase 1 (CARM1) is an arginine methyltransferase that catalyzes dimethylation of histone H3 (H3R17) at arginine 17. Lately, it has been suggested that CARM1 is associated with human carcinogenesis, and the CARM1-selective inhibitor, TP-064, has been shown to be a potential therapeutic agent for multiple myeloma. However, the physiological significance of CARM1 in endometrial cancer remains unclear. Therefore, we aimed to explore the role of CARM1 and the effect of TP-064 in endometrial cancer. To this end, we analyzed CARM1 expression in endometrial cancer using quantitative real-time polymerase chain reaction and examined the antitumor mechanism with CARM1 knockdown endometrial cancer cells. Moreover, we evaluated the therapeutic capability of TP-064 in endometrial cancer cells. CARM1 was remarkably overexpressed in 52 endometrial cancer tissues compared to normal endometrial tissues. The growth of CARM1 knockdown endometrial cancer cells was suppressed and CARM1 knockdown induced apoptosis. TP-064 also inhibited endometrial cancer cell growth and declined the number of endometrial cancer cell colonies. These data suggest that CARM1 may be a powerful therapeutic target for endometrial cancer. • CAMR1 was significantly overexpressed in 52 endometrial cancer tissues. • CARM1 -knockdown suppressed endometrial cancer cell growth and induced apoptosis. • A selective inhibitor of CARM1 TP-064 suppressed endometrial cancer cell growth. [ABSTRACT FROM AUTHOR]

p38δ is a member of p38 mitogen-activated protein kinases (MAPKs) family that displays cell- and tissue-specific expression patterns. Recent studies demonstrate that p38δ is centrally involved in several pathologic events, such as diabetes, neurodegeneration diseases, inflammatory diseases, and cancer, and suggest that it may be a potential target for diagnosis and therapy of specific diseases. A nanobody is a new type of antibody that exhibits high antigen-binding activity, solubility, stability, and easy production. This study utilized phage display to isolate nanobodies specifically against p38δ from a fully synthetic nanobody library. Two of them, nanobodies Nb13-6 and Nb13-1, display high binding activity to p38δ, less cross-reactivity with other p38 MAPKs, and high thermal and pH stabilities. Modeling and docking analysis indicated that Nb13-6 is mostly linked to the activation loop of p38δ. Furthermore, detailed studies revealed that Nb13-6 inhibited the protein kinase activity of p38δ and the growth of cancer cells. Therefore, this study provides p38δ-specific nanobodies that are promisingly exploited for diagnosing and treating p38δ-associated diseases. • The isolated nanobodies specifically bind to p38δ. • Anti-p38δ nanobody Nb13-1 and Nb13-6 display high thermal and pH stability. • Nanobody Nb13-6 binds the activation loop of p38δ. • Nanobody Nb13-6 inhibits the protein kinase activity of p38δ and the growth of breast cancer cells. [ABSTRACT FROM AUTHOR]

Early-stage gastric cancer (GC) is asymptomatic. How to diagnose the early-stage GC is challenging. The sensitivity and specificity of diagnosing signatures for early-stage patients are still poor. Elastic-net-based analysis was used to identify potential diagnostic signatures of early-stage GC. The expression level of candidate gene was evaluated by immunohistochemistry staining. The potential function of candidate gene was verified by overexpressing in vitro. Consensus genes (including GAMT) were identified using the different strengths of the penalty. Surprisingly, GAMT was still identified even if some multicollinear variables were deleted directly. IHC staining showed that there are no GAMT-positive signals in the cell nuclei of all tumor tissues, while GAMT does express in nuclei of adjacent normal tissue. There are 16.33% positive cell nuclei in paracancerous tissues. In addition, the number of larger-area colonies of overexpression-GAMT group, empty-vector group, and AGS group is 70 ± 29.21 , 151.33 ± 15.95 , and 111.67 ± 22.03 , respectively. Number of larger colonies in group with overexpression of GAMT is significantly less than control groups. Elastic-net-penalty-based workflow is a effective tool to identify diagnostic biomarker for early-stage solid tumor. GAMT has strong potential to be the diagnostic biomarker for the early-stage GC. • GAMT can be used as potential diagnostic marker for early-stage gastric cancer. • Overexpressing GAMT could suppress the growth of gastric cancer cell. • Elastic-net-penalty-based workflow is effective to identify diagnostic marker. [ABSTRACT FROM AUTHOR]

Abnormal activation of the mechanistic target of rapamycin (mTOR) signaling is commonly observed in many cancers and attracts extensive attention as an oncology drug discovery target, which is encouraged by the success of rapamycin and its analogs (rapalogs) in treatment of mTORC1-hyperactive cancers in both pre-clinic models and clinical trials. However, rapamycin and existing rapalogs have typically short-lasting partial responses due to drug resistance, thereby triggering our interest to investigate a potential mTORC1 inhibitor that is mechanistically different from rapamycin. Here, we report that hayatine, a derivative from Cissampelos , can serve as a potential mTORC1 inhibitor selected from a natural compound library. The unique properties owned by hayatine such as downregulation of mTORC1 activities, induction of mTORC1's translocation to lysosomes followed by autophagy, and suppression on cancer cell growth, strongly emphasize its role as a potential mTORC1 inhibitor. Mechanistically, we found that hayatine disrupts the interaction between mTORC1 complex and its lysosomal adaptor RagA/C by binding to the hydrophobic loop of RagC, leading to mTORC1 inhibition that holds great promise to overcome rapamycin resistance. Taken together, our data shed light on an innovative strategy using structural interruption-based mTORC1 inhibitors for cancer treatment. • Identification of compounds against cancer cells with mTORC1 inhibition using cell size alteration as the indicator. • Hayatine inhibited mTORC1 and induced autophagic influx. • Hayatine blocked amino acid-induced mTORC1 activation. • Hayatine working as mTOR-RagA/C interaction disruptor under amino acid treatment. [ABSTRACT FROM AUTHOR]

Lung cancer is one of the most malignant and prevalent tumors and accounts for the vast majority of cancer death worldwide. However, the molecular mechanisms underlying lung cancer progression are poorly understood. Here, we reveal that both transcription and protein expression levels of Cox15 were increased in lung cancer. Nrf2 specifically binds to the Cox15 promoter and triggers Cox15 expression at the transcriptional level. Cox15 functions as a novel oncogene that facilitates lung cancer cell proliferation. Additionally, Aripiprazole, a potent inhibitor of Cox15, executives profoundly suppressive effects on lung cancers cells growth and tumor progression in vivo and in vitro through exerting therapeutic effects. Taken together, our results unravel that Cox15 holds great potential to act as a prognostic molecule for lung cancer patients' prognosis in the future. • Cox15 was highly expressed in lung cancer and serves as new prognostic biomarker. • Nrf2 specifically binds to Cox15 promoter and triggers Cox15 expression in transcriptional level. • Aripiprazole executives a profoundly suppressive effects on lung cancers cells growth through inhibiting Cox15 expression. [ABSTRACT FROM AUTHOR]

Prostate cancer, the most common non-cutaneous male cancer, is a public health problem with a third prevalence worldwide. PYCR1 and miR-1207-5p dysregulations were found in cancer progression. Our study aims to reveal the biological role of miR-1207-5p-PYCR1 axis in prostate cancer progression. First, we investigated the expression of miR-1207-5p in prostate cancer tissues and cell lines by RT-qPCR. Next, we confirmed miR-1207-5p targeting PYCR1 by luciferase assay. CCK-8 assay, BrdU assay, flow cytometry, and tanswell assay were applied for examining cell proliferation, apoptosis, and invasion in prostate cancer cells, respectively. In the present study, decreased miR-1207-5p expression was obviously observed in prostate cancer tissues and cells. Upregulation of miR-1207-5p hampered cellular proliferation and invasion, while enhanced cellular apoptosis. In addition, upregulation of PYCR1 elevated cell proliferation and invasion, but repressed apoptosis of prostate cancer cells. Moreover, miR-1207-5p inhibited the expression of PYCR1 to repress prostate cancer tumorigenesis. MiR-1207-5p inhibited the expression of PYCR1 to repress the progression of prostate cancer by inhibiting cell growth and elevating cell apoptosis. Overall, our study clarifies the biological role of miR-1207-5p-PYCR1 axis in prostate cancer progression, which might be effective biomarkers for clinical treatment of prostate cancer. • miR-638 and PYCR1 were the key regulators in prostate cancer. • MiR-1207-5p repressed cell proliferation and migration and promoted cell apoptosis in prostate cancer. • MiR-1207-5p directly targeted PYCR1. • MiR-1207-5p targeting PYCR1 suppressed the progression of prostate cancer. [ABSTRACT FROM AUTHOR]

Helicobacter pylori infection is a crucial factor in the development of gastric cancer (GC). Molecular therapeutic targets and mechanisms contributing to H. pylori infection-associated GC induction are poorly understood and this study aimed to fill that research gap. We found that the nuclear receptor estrogen-related receptor gamma (ESRRG) is a candidate factor influencing H. pylori infection-driven GC. ESRRG suppressed H. pylori infection and cell growth induced by H. pylori infection in GC cells and organoid models In addition, H. pylori infection downregulates ESRRG expression. Gene expression profiling revealed that trefoil factor 1 (TFF1), a well-known tumor suppressor in GC, is a downstream target of ESRRG. Mechanistically, ESRRG directly binds to the TFF1 promoter and induces TFF1 gene expression. Furthermore, TFF1 activation by ESRRG was inhibited by nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)/p65, which is induced by inflammation, such as by H. pylori infection. Our current study provides new molecular insights into how ESRRG regulates H. pylori infection, contributing to GC development. We suggest that modulation of ESRRG-suppressing H. pylori infection could be a therapeutic target for the treatment of GC patients. • Nuclear receptor, ESRRG has a crucial role in Helicobacter pylori infection-leading gastric cancer. • ESRRG-TFF1 axis modulates Helicobacter pylori infection and suppresses cancer cell growth. • ESRRG activity is pivotal for gastric cancer promotion. [ABSTRACT FROM AUTHOR]

The epidermal growth factor receptor extracellular domain III (EGFR-ECDIII) protein is a promising target of anti-cancer research, and its production in Escherichia coli would thus represent significant benefits. However, despite its moderate size (19 kDa), the expression of EGFR-ECDIII in E.coli is hampered by the presence of multiple cysteines producing misfolded proteins with incorrect S-S bonds. In our study, we show that a short 12-residue solubility enhancing peptide (SEP) tag containing nine arginines (C9R) attached at the C-terminus of EGFR-ECDIII reduces the inclusion body formation and increases the final yield by six times (20 mg/L). EGFR-ECDIII-C9R purified from the soluble fraction eluted as a sharp single RP-HPLC peak, suggesting a single S-S bond pairing. Biophysical characterization using circular dichroism, fluorescence, and light scattering confirmed its native-like properties together with reversible thermal denaturation. The binding activity of EGFR-ECDIII-C9R to anti-EGFR-VHH7D12, a single-domain antibody with specific binding to the ECDIII, was assessed by sandwich ELISA. Further, we produced anti-EGFR-ECDIII-C9R antisera in mouse models and anti-sera inhibited A431 cancer cells' growth. These results demonstrate that the SEP tag enables the rapid production of the multiple disulfide-bonded EGFR-ECDIII in E. coli having native-like biophysical properties and producing neutralizing antibodies. • C9R tag increased the solubility of a multi-SS-bonded EGFR-ECDIII-C9R in E.coli and yield by 6 fold. • CD, fluorescence, and light scattering confirmed EGFR-ECDIII-C9R's native-like properties. • Binding of EGFR-ECDIII to VHH7D12, a single-domain antibody, was demonstrated by sandwich ELISA. • EGFR-ECDIII-C9R produced high titer anti-(native) EGFR antisera inhibiting cancerous cell growth. [ABSTRACT FROM AUTHOR]

PUMA (p53-upregulated modulator of apoptosis) is localized in mitochondria and a direct target in p53-mediated apoptosis. p53 elicits mitochondrial apoptosis via transcription-dependent and independent mechanisms. p53 is known to induce apoptosis via the transcriptional induction of PUMA, which encodes proapoptotic BH3-only members of the Bcl-2 protein family. However, the transcription-independent mechanisms of human PUMA remain poorly defined. For example, it is not known whether PUMA interacts directly with the DNA binding domain (DBD: residues 92–293) of p53 in vitro. Here, the structure of the complex between the DBD of p53 and PUMA peptide was elucidated by X-ray crystallography. Isothermal titration calorimetry showed that PUMA peptide binds strongly with p53 DBD, and the crystal structure of p53-PUMA peptide complex revealed it contains four molecules of p53 DBD and one PUMA peptide per asymmetric unit in space group P 1. PUMA peptide bound to the N-terminal residues of p53 DBD. A cell proliferation assay demonstrated PUMA peptide inhibited the growth of a lung cancer cell line. These results contribute to understanding of the mechanism responsible for p53-mediated apoptosis. • The PUMA gene is a transcriptional target of p53. • The first crystal structure of p53 DBD and PUMA complex was determined. • PUMA peptide inhibited the growth of a lung cancer cell line. • These findings provide further insight of potential drug targets for cancer therapy. • The p53 DBD was physically bound to PUMA peptide with an apparent K D value. [ABSTRACT FROM AUTHOR]

In the tumor environment, hypoxia promotes tumor progression, such as cancer cell growth, migration and chemoresistance. This study aimed to evaluate the roles of free fatty acid receptors (FFARs) in the regulation of cancer cell functions under hypoxic conditions, using fibrosarcoma HT1080 cells. HT1080 cells expressed FFAR1 , FFAR2 and FFAR3 genes, but not FFAR4 gene. FFAR1 , FFAR2 and FFAR3 expression levels in HT1080 cells cultured at 1 % O 2 were elevated, compared with 21 % O 2. The cell growth activities of HT1080 cells cultured at 21 % O 2 were inhibited by acetic acid (AA) and propanoic acid (PA), but not 1 % O 2. HT1080 cell motility was markedly reduced by culturing at 1 % O 2. The cell growth and motility of HT1080 cells were enhanced by FFAR2 knockdown. The cell viability to cisplatin (CDDP) of HT1080 cells cultured at 1 % O 2 was increased, compared with 21 % O 2. FFAR2 knockdown suppressed the cell viability to CDDP of HT1080 cells. On the other hand, the cell motility and viability to CDDP of HT1080 cells cultured at 21 % O 2 were suppressed by TUG-770. When HT1080 cells were cultured at 1 % O 2 , the cell motility and viability to CDDP were decreased, correlating with FFAR1 expression level. Moreover, FFAR1 knockdown increased the cell viability to CDDP of HT1080 cells cultured at 1 % O 2. These results suggest that FFAR-mediated signaling plays an important role in the modulation of cellular functions of HT1080 cells under hypoxic conditions. • FFAR1 , FFAR2 and FFAR3 expressions in HT1080 cells were elevated by culturing at 1 % O 2. • FFAR2 inhibited and FFAR3 stimulated cell growth and migration of HT1080 cells cultured at 1 % O 2. • Cell viability to CDDP was enhanced by Gi protein via FFAR2 and FFAR3 in HT1080 cells cultured at 1 % O 2. • HT1080 cell motility and viability to CDDP at 1 % O 2 were suppressed by FFAR1. • FFARs are involved in the modulation of cellular functions of HT1080 cells under hypoxic conditions. [ABSTRACT FROM AUTHOR]

ANP32B is a histone chaperone that interacts with various transcription factors that regulate cancer cell proliferation, immigration, and apoptosis. c -Myc, a well-known oncogenic protein, is a principal player in the initiation and progression of prostate cancer (PC). The means by which ANP32B and c -Myc act remain unknown. We downloaded clinical data from the GEO, TCGA, and other databases to explore ANP32B expression and its effects on the survival of PC and normal tissues. ANP32B-knockdown cell lines were used to evaluate how ANP32B affected cell proliferation in vitro and in vivo. Gene set enrichment analysis and RNAseq were employed to define how ANP32B regulated PC pathways. Immunohistochemical measures were used to detect the expression levels of relevant proteins in xenografts and PC tissues. ANP32B expression increased in PC tissues; ANP32B knockdown inhibited cell growth but this was rescued by c -Myc signaling. ANP32B is thus a PC oncogene and may serve as a valuable therapeutic target when seeking to treat PC. • ANP32B expression is markedly elevated in prostate cancer (PC) and is correlated with PC progression. • ANP32B inhibition decreases the proliferation and blocks the cell cycle in PC cells. • ANP32B inhibition suppresses the proliferation of PC by regulating c -Myc signaling. • Identification of ANP32B as a PC oncogene and a valuable therapeutic target. [ABSTRACT FROM AUTHOR]

DT-13, the principal active component of Mysidium shortscapes from the Liliaceae family, has garnered substantial interest in cancer therapy owing to its potential anticancer properties. This study investigated the effects of DT-13 on the proliferation and apoptosis of human pancreatic cancer cell lines and aimed to elucidate the underlying mechanisms. PANC1 and CFPAC1 cells were exposed to DT-13 and their proliferation was assessed using RTCA and clone formation assays. Apoptotic protein expression was analyzed by western blotting, and apoptotic cells were identified by flow cytometry. RNA was extracted from DT-13 treated and untreated PANC1 cells for RNA sequencing. Differentially expressed genes were identified and subjected to GO bioprocess, KEGG pathway analysis, and western blotting. Finally, to evaluate tumor growth, CFPAC1 cells were subcutaneously injected into BALB/c nude mice. DT-13 inhibited proliferation and induced apoptosis of PANC1 and CFPAC1 cells by activating the AMPK/mTOR pathway and suppressing p70 S6K. Moreover, DT-13 hindered the growth of CFPAC1 xenograft tumors in nude mice. DT-13 effectively inhibited the growth of human pancreatic cancer cells. • DT-13 can prompt apoptosis and curb pancreatic cancer cell growth. • Basic tests show DT-13 controls pancreatic cancer growth via AMPK/mTOR. • DT-13 binds, forming hydrogen bonds with amino acids in AMPK's active pocket. [ABSTRACT FROM AUTHOR]

Here, we report that human lactoferrin (hLF), known for its anticancer properties, induced intracellular activation of the Na+/H+ exchanger (NHE) 7 in human lung cancer PC-9 cells. Compared to non-fused hLF, the fusion of human serum albumin (HSA) with hLF (hLF-HSA) facilitated its internalization into PC-9 cells in a caveolae-mediated manner, thereby exhibiting enhanced anti-proliferative effects. Although hLF alone did not exhibit any discernible effects, hLF-HSA resulted in organelle alkalization as detected using an acidotropic pH indicator. hLF-HSA-induced elevation of organelle pH and inhibition of cancer growth were abolished by NHE7 siRNA. hLF-HSA upregulated NHE7. Thus, upon cellular uptake, hLF-HSA triggers proton leakage through the upregulation of NHE7. This process led to organelle alkalization, probably in the trans -Golgi network (TGN) as suggested by the localization of NHE7 in PC-9 cells, thereby suppressing lung cancer cell growth. Forcing the cellular uptake of hLF alone using a caveolae-mediated endocytosis activator led to an increase in organelle pH. Furthermore, cell entry of hLF also activated proton-loading NHE7, leading to organelle acidification in the pancreatic cancer cell line MIA PaCa-2. Therefore, the intracellularly delivered hLF functions as an activator of NHE7. [Display omitted] • Forcing the intracellular delivery of human lactoferrin alone activates Na+/H+ exchanger (NHE) 7. • Intracellular delivery of human lactoferrin by albumin fusion (hLF-HSA) activates NHE7. • Disruption of Golgi function through activation of NHE7 by hLF-HSA inhibits cancer cell growth. [ABSTRACT FROM AUTHOR]

Geoffroea decorticans (chañar) is commonly used for culinary and medicinal purposes in rural communities. The aim of this work was to chemically characterize three Geoffroea decorticans extracts and determine their capacity to modulate the wnt/β-catenin pathway. This signaling pathway plays a key role in embryonic development but its overactivation leads to cancer cell growth. Phytochemical analysis of extracts showed presence of major classes of phytochemicals. Gas chromatography-mass spectrometry results revealed the presence of acids, esters and furanic compounds. Using Xenopus embryos as in vivo model organisms, we found that the extracts modulated dorso-ventral axis formation and rescued hyperdorsalized phenotypes produced by LiCl treatment. In agreement with these findings, Geoffroea decorticans extracts decreased β-catenin levels and suppressed the expression of wnt target genes such as xnr3 and chordin , thus demonstrating an inhibitory regulation of the wnt/β-catenin signaling pathway. All these results support a new role for Geoffroea decorticans fruit derivatives with possible anti-carcinogenic actions. Image 1 • Geoffroea decorticans (Gd) extracts exhibit predominant acids, esters and furanic compounds. • Gd extracts affect axis formation in Xenopus embryos, producing ventralized phenotypes. • Gd extracts reverse the effects of LiCl, a wnt/β-catenin pathway activator. • Gd extracts suppressed the expression of wnt target genes and decrease β-catenin levels in Xenopus embryos. [ABSTRACT FROM AUTHOR]

Environmental toxicants such as dioxins and polycyclic aromatic carbons are risk factors for pancreatitis and pancreatic cancer. These toxicants activate aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, of which activation regulates many downstream biological events, including xenobiotic metabolism, inflammation, and cancer cell growth and transformation. Here, we identified that environmental toxicant-activated AHR increased expression of metastasis associated lung adenocarcinoma transcript 1 (MALAT1) in pancreatic cancer cells and pancreatic tissues. The MALAT1 is a long noncoding (lnc) RNA which interacts with Enhancer of Zeste 2 (EZH2), a histone methyltransferase with epigenetic silencer activity, and the MALAT1-EZH2 interaction increased its epigenetic silencing activity. In contrast, AHR antagonist, CH223191 or resveratrol, counteracted the AHR-mediated MALAT1 induction and MALAT1-enahnced EZH2 activity. Collectively, these results revealed a novel pathway of how environmental exposure leads to epigenetic alteration via activation of AHR-MALAT1-EZH2 signaling axis under pancreatic tissue- and cancer cell-context. • TCDD increased MALAT1 expression via AHR activation. • AHR antagonists inhibited AHR-mediated MALAT1 induction. • MALAT1 interacted with EZH2 and increased its epigenetic silencing function. • The AHR-MALAT1-EZH2 signaling linked environmental exposure to epigenetic alteration. [ABSTRACT FROM AUTHOR]

Angiogenesis plays a vital role in tumor progression and metastasis. To better understand the role of anesthesia in tumor biology, we previously reported that bupivacaine displayed the inhibitory effects in endothelial cells. In this work, we demonstrated that fentanyl, an opioid medication commonly used in cancer patients, stimulated tumor angiogenesis. We found that fentanyl at nanomolar concentrations significantly stimulated capillary network formation of human lung tumor-associated endothelial cell (HLT-EC) in a similar manner as vascular endothelial growth factor (VEGF), and furthermore that the stimulatory effect of fentanyl was mainly involved in early stage of HLT-EC vascular structure assembly. Particularly, fentanyl significantly increased HLT-EC growth and migration. Fentanyl also protected HLT-EC from apoptosis induced by growth factor withdrawal. In contrast, the same concentrations of fentanyl did not affect human lung cancer cell growth and survival. Fentanyl stimulated migration of some but not all tested human lung cancer cells. Mechanism analysis suggested that fentanyl activates multiple pro-angiogenic signaling pathways, including VEGFR2/FAK/PI3K/Akt and small GTPases. Our work systematically demonstrates that fentanyl stimulates tumor angiogenesis via activating multiple pro-angiogenic signaling pathways. Our findings highlight the potential adverse effect of fentanyl in cancer patients. • Fentanyl stimulates early stage of lung tumor angiogenesis. • Fentanyl increases HLT-EC migration, growth and survival. • Fentanyl activates VEGFR2/FAK, small GTPases and PI3K/Akt in HLT-EC. • Fentanyl increases lung cancer cell migration but not proliferation. [ABSTRACT FROM AUTHOR]

Human breast tumors are not fully autonomous. They are dependent on nutrients and growth-promoting signals provided by the supporting stromal cells. Within the tumor microenvironment, one of the secreted macromolecules by tumor cells is activin A, where we show to downregulate CD36 in fibroblasts. Downregulation of CD36 in fibroblasts also increases the secretion of activin A by fibroblasts. We hypothesize that overexpression of CD36 in fibroblasts inhibits the formation of solid tumors in subtypes of breast cancer models. For the first time, we show that co-culturing organoid models of breast cancer cell lines of MDA-MB-231 (e.g., a triple-negative line) or MCF7 (e.g., a luminal-A line) with CD36+ fibroblasts inhibit the growth and normalizes basal and lateral polarities, respectively. In the long-term anchorage-independent growth assay, the rate of colony formation is also reduced for MDA-MB-231. These observations are consistent with the mechanism of tumor suppression involving the downregulation of pSMAD2/3 and YY1 expression levels. Our integrated analytical methods leverage and extend quantitative assays at cell- and colony-scales in both short- and long-term cultures using brightfield or immunofluorescent microscopy and robust image analysis. Conditioned media are profiled with the ELISA assay. • CD36 expression in fibroblasts is reduced as a result of exposure to the physiological level of tumor-secreting activin A. • Co-culture of CD36+ fibroblast cells (FB) with the organoid models of MDA-MB-231 induces growth inhibition. • Co-culture of CD36+ FB with MCF7 breast cancer cell lines induces reversion of aberrant lateral and basal polarities. [ABSTRACT FROM AUTHOR]

Charcoal-stripped fetal bovine serum (CS-FBS) is frequently used in studies on hormone-responsive cancers to provide hormone-free cell culture conditions. CS-FBS may influence the growth of cancer cells; however, the underlying mechanisms remain unclear. In this study, we aimed to clarify the effects of CS-FBS on distinct subtypes of breast cancer cells. We found that the crucial oncoprotein c-Myc was significantly inhibited in estrogen receptor alpha (ER-α)-positive breast cancer cells when cultured in CS-FBS-supplemented medium, but it was not suppressed in ER-α-negative cells. The addition of 17β-estradiol (E2) to CS-FBS-supplemented medium rescued the CS-FBS-induced inhibition of c-Myc, while treatment with 5α-dihydrotestosterone (DHT) suppressed c-Myc expression. Our data demonstrated that CS-FBS may impede the growth of ER-α-positive breast cancer cells via c-Myc inhibition, and this was possibly due to the removal of estrogen. These results highlighted that the core drivers of c-Myc expression were subtype-specific depending on the distinct cell context and special caution should be exercised when using CS-FBS in studies of hormone-responsive cancer cells. Image 1 • c-Myc was eliminated in ER-α-positive cells under CS-FBS culture conditions. • E2 rescued and DHT inhibited c-Myc in ER-α-positive cells cultured with CS-FBS. • CS-FBS impeded the transcription of c-Myc and its targets in ER-α-positive cells. [ABSTRACT FROM AUTHOR]

Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy, with an overall 5-year survival rate of only 30%. EOC is associated with drug resistance, frequent recurrence, and poor prognosis. A major contributor toward drug resistance might be cancer stem cells (CSCs), which may remain after chemotherapy. Here, we aimed to find therapeutic agents that target ovarian CSCs. We performed a high-throughput screening using the Clinical Compound Library with a sphere culture of A2780 EOCs. Poziotinib, a pan-human epidermal growth factor receptor (HER) inhibitor, decreased sphere formation, viability, and proliferation, and induced G1 cell cycle arrest and apoptosis in ovarian CSCs. In addition, poziotinib suppressed stemness and disrupted downstream signaling of Wnt/β-catenin, Notch, and Hedgehog pathways, which contribute to many characteristics of CSCs. Interestingly, HER4 was overexpressed in ovarian CSCs and Poziotinib reduced the phosphorylation of STAT5, AKT, and ERK, which are regulated by HER4. Our results suggest that HER4 may be a promising therapeutic target for ovarian CSCs, and that poziotinib may be an effective therapeutic option for the prevention of ovarian cancer recurrence. • Poziotinib decreases viability and proliferation of ovarian cancer stem cells. • Poziotinib induces G1 cell cycle arrest and apoptosis in ovarian cancer stem cells. • Pozioitinib inhibits stemness and Wnt, Notch, and Hedgehog signaling. • Pozioitinib reduces HER4-mediated signals and inhibits stemness in ovarian cancer stem cells. • Pozioitinib can be used to treat drug-resistant and recurrent ovarian cancer. [ABSTRACT FROM AUTHOR]

In cell competition, a secreted death signal can determine cell fate. However, the nature of such a signal remains unclear. In this study, conditioned medium from HeLa cells (HeLa CM) inhibited growth of A549 and MCF-7 cells. Through HeLa CM fractionation, glucose 6-phosphate isomerase/autocrine motility factor (GPI/AMF) was identified as the main growth inhibitor. Previously, AMF was known for its mitogenic, motogenic, and differentiation functions and was implicated in tumor progression and metastasis. HeLa CM lost its growth inhibitory property after treatment with erythrose-4-phosphate (E4P) or anti -GPI antibody. Purified HeLa recombinant AMF (rAMF) proteins inhibited the growth of A549, MDA-MB-232, MCF-7, AsPC-1, DU145, Hep-2, Hep G2, and HT-29 cells. However, growth of HL-60, SKOV3, U-87 MG, SNU-484, U-87 MG, and 3T3-L1 cells was little affected. In a Transwell assay, HeLa rAMF effectively reduced A549 cell migration and invasion. HeLa rAMF effectively induced apoptosis in A549 cells, apparently by reducing the levels of Bcl-2, GPI, and poly(ADP-ribose) polymerase (PARP)14 and activating caspase-3 and p53. HeLa rAMF antagonized HER2 and the AMF receptor (AMFR or GP78) in relation to the AKT/EKT signaling pathway. These results suggest that HeLa AMF could act as a diffusible death signal that could induce cancer cell–selective growth inhibition and apoptosis. • Autocrine motility factor (AMF) induces cancer cell motility, proliferation, and metastasis. • AMF binding to its receptor activates PI3K/AKT and MAPK/ERK signaling. • AMF secreted by HeLa cells can selectively inhibit cancer cell growth. • HeLa AMF can regulate AKT/ERK signaling and promote pro-apoptotic processes. • AMF is a potent death signal that can kill a broad spectrum of cancer cells. [ABSTRACT FROM AUTHOR]

We improved miR-143, which inhibits the growth of cancer cells, by the replacement of the passenger strand. As a result, new miR-143 variants were developed with a single mismatch at the 4th position from the 3′-terminal of the guide strand and an RNA passenger strand with a G-rich flanking DNA region. A reporter gene assay showed that the 80% inhibitory concentration of the new miR-143, long miR-143, was 69 pM, which was three times lower than that of natural miR-143. Long miR-143 inhibited the growth of two cancer cell lines, HeLa–S3 and MIAPaCa-2, more effectively than natural miR-143. This method could be applied to other miRNA families and should be useful for the development of miRNA drugs. Image 1 • We improved miR-143 by the replacement of the passenger strand. • A single mismatch near the 3′-terminal of the guide strand enhanced miRNA activity. • An RNA passenger strand with a G-rich flanking DNA region also enhanced. • Improved "long miR-143" showed more than 3 times the activity of natural miR-143. • Long miR-143 inhibited the cancer cell growth more effectively than natural miR-143. [ABSTRACT FROM AUTHOR]

The DEAD-box family of RNA helicases plays essential roles in both transcriptional and translational mRNA degradation; they unwind short double-stranded RNA by breaking the RNA–RNA interactions. Two DEAD-box RNA helicases, eukaryotic translation initiation factor 4A3 (eIF4A3) and DEAD-box helicase 3 (DDX3X), show high homology in the ATP-binding region and are considered key molecules for cancer progression. Several small molecules that target eIF4A3 and DDX3X have been reported to inhibit cancer cell growth; however, more potent compounds are required for cancer therapeutics, and there is a critical need for high-throughput assays to screen for RNA helicase inhibitors. In this study, we developed novel fluorescence resonance energy transfer-based high-throughput RNA helicase assays for eIF4A3 and DDX3X. Using these assays, we identified several eIF4A3 allosteric inhibitors whose inhibitory effect on eIF4A3 ATPase showed a strong correlation with inhibitory effect on helicase activity. From 102 compounds that exhibited eIF4A3 ATPase inhibition, we identified a selective DDX3X inhibitor, C1, which showed stronger inhibition of DDX3X than of eIF4A3. Small-molecule helicase inhibitors can be valuable for clarifying the molecular machinery of DEAD-box RNA helicases. The high-throughput quantitative assays established here should facilitate the evaluation of the helicase inhibitory activity of compounds. • High-throughput RNA helicase assays were developed for eIF4A3 and DDX3X. • ATPase and helicase activity were well-correlated for allosteric eIF4A3 inhibitors. • Screening with the DDX3X helicase assay identified a selective DDX3X inhibitor. • These new helicase assays are valuable tools for identifying potent inhibitors. [ABSTRACT FROM AUTHOR]

Pancreatic cancer (PC) is a fatal disease; most patients are asymptomatic before the disease enters the advanced stage, but molecular mechanisms of early PC that can be exploited for diagnosis are not clear. Long noncoding RNAs (lncRNAs) play key roles in the progression of PC. In this study, we found that the expression of the lncRNA EPIC1 (Lnc-EPIC1) is high in PC and closely related to tumor size, TNM staging and lymph node metastasis status. Silencing Lnc-EPIC1 by siRNA targeting could significantly inhibit the cell growth and colony formation ability of PC cells and induced G1/S cell cycle arrest and apoptosis in PC cells. Lnc-EPIC1-specific siRNAs could downregulate the expression of cyclins and CDKs, such as CDC20, CDK4 and Cyclin A1. Knocking out YAP1 with the CRISPR/Cas-9 gene editing method recapitulated the effects of the Lnc-EPIC1-specific siRNAs on cell growth, colony formation ability and apoptosis in PC cells. In addition, the Lnc-EPIC1-specific siRNAs did not further inhibit cell growth or promote apoptosis in YAP1-knockout (YAP1-KO) cells. RNA immunoprecipitation (RIP) results showed that there was a direct interaction between Lnc-EPIC1 and YAP1. An Lnc-EPIC1-overexpressing lentiviral vector promoted the growth of PC cells. The results show that Lnc-EPIC1 interacts with YAP1 to promote the progression of PC. Image 1 • Lnc-EPIC1 and YAP1 is highly expressed in pancreatic cancer. • Lnc-EPIC1 may promote tumor progression by promoting cell growth and reducing apoptosis. • Lnc-EPIC1 regulates PC progression by targeting YAP1, which impacts the downstream molecules CDC20, CDK4 and Cyclin A1. [ABSTRACT FROM AUTHOR]

Advanced colon cancer is extremely difficult to cure, underscoring the need to develop novel therapeutic agents. Prenylated curcumins that are semisynthetic curcumin derivatives with significant anti-cancer potential have been studied herein to assess their therapeutic potential for colon cancer and tested to this aim in vitro for their growth inhibitory properties against 5-fluorouracil + oxaliplatin resistant human colon cancer CR-HT29 and HCT-116 cells. The resulting most active product, gercumin (mono- O -geranylcurcumin), has been further tested for its synergistic effects with FOLFOX (a combination of 5-fluorouracil and oxaliplatin) on the same cell lines. Activity of this combination on colonosphere formation was also investigated. Gercumin was able to suppress the growth of cancer cells with a potency similar to that of curcumin. A synergistic effect of this compound and FOLFOX was also observed. doses tested for synergy in the colonosphere assays did not show greater suppression of colonosphere formation than independent treatment with either reagent alone. Only one of the combinations was shown to be more effective at suppressing colonosphere formation [gercumin 5 μM + FOLFOX (2x)]. Thus, the growth inhibitory effects of curcumin against human cancer cells can be modulated and enhanced by the introduction of hydrophobic chains, normally found in several natural compounds, like the geranyl one. Such compounds are also able to synergize with known chemotherapeutics. • Prenylated curcuminoids have been assyaed as colon cancer chemotherapeutics in vitro. • Gercumin has been assayed as a syngergic agents with 5-fluorouracil and oxaliplatin. • Gercumin and FOLFOX were able to suppress the growth of cancer cells in a way similar to curcumin. [ABSTRACT FROM AUTHOR]

Farnesoid X receptor (FXR) exhibits critical anti-cancer functions in several types of cancer, including colorectal cancer, in vitro and in vivo. However, the underlying mechanism remains unclear. We evaluated pharmacological activation of FXR with the synthetic agonist GW4064 using comprehensive proteomic analysis in colorectal cancer cell lines (HCT116, SW480, and DLD1). Among the commonly detected proteins in all three cell lines, death receptor 5 (DR5) was the most up-regulated protein, and key autophagy-related proteins, such as microtubule-associated protein 1 light chain 3 alpha/beta (MLP3A/3B) and p62 sequestosome-1 (SQSTM), were also differentially expressed. Western blot analysis showed that GW4064 stimulation induced activation of the extrinsic death signaling pathway in all cell lines and induced activation of the intrinsic death signaling pathway in DLD1 cells. Western blotting showed that DR5 up-regulation was associated with inhibition of autophagic activity. These results suggest that FXR activation induced DR5 up-regulation through inhibition of autophagic activity and the DR5-related death signaling pathway. In addition, DR5 selective ligand, also known as TRAIL, has been widely used for anti-cancer treatment in several clinical trials. Co-treatment of TRAIL with GW4064 synergistically inhibited colorectal cancer cell proliferation as compared with single treatments. To the best of our knowledge, our results provide novel insights into FXR function in cancer cell lines. These findings may contribute to a new therapeutic strategy for colorectal cancer. • FXR activation by GW4064 suppressed proliferation and induced apoptosis in colorectal cancer cells. • GW4064 treatment upregulated DR5, LC-3, and p62 expression in colorectal cancer cells. • GW4064 stimulation induced the extrinsic death signaling pathway by DR5. • DR5 upregulation by FXR activation through inhibition of autophagy flux. [ABSTRACT FROM AUTHOR]

Inhibition of gamma-glutamylcyclotransferase (GGCT), which is highly expressed in various cancer tissues, exerts anticancer effects both in vitro and in vivo. Previous studies have shown that depletion of GGCT blocks the growth of MCF7 breast cancer cells via upregulation of the cyclin-dependent kinase inhibitor p21WAF1/CIP1 (p21); in addition, induction of autophagy plays a role in the upregulation of p21 upon GGCT knockdown. However, the mechanisms underlying induction of p21 in cancer cells are not fully understood. Here, we show that GGCT knockdown in PC3 human prostate cancer and A172 glioblastoma cells upregulates the mRNA and nuclear protein levels of Forkhead box O transcription factor 3a (FOXO3a), a transcriptional factor involved in tumor suppression. Simultaneous knockdown of FOXO3a and GGCT in PC3 and A172 cells attenuated upregulation of p21, followed by growth inhibition and cell death. Furthermore, simultaneous knockdown of GGCT and AMP-activated protein kinase (AMPK) α, a metabolic stress sensor, in PC3 and A172 cells led to marked attenuation of cellular responses induced by GGCT knockdown, including an increase in FOXO3a phosphorylation at Ser413, upregulation of p21, growth inhibition, and cell death. These results indicate that the AMPK–FOXO3a–p21 axis plays an important role in inhibition of cancer cell growth by depletion of GGCT. Image 1 • FOXO3a is identified as a mediator for p21 upregulation by GGCT depletion. • AMPK is required for the FOXO3a-mediated p21 upregulation by GGCT depletion. • AMPK–FOXO3a–p21 axis plays a role in cancer cell growth inhibition by GGCT depletion. [ABSTRACT FROM AUTHOR]

Eukaryotic translation initiation factor 3 subunit D (EIF3D) binds to the 5′-cap of specific mRNAs, initiating their translation into polypeptides. From a pathological standpoint, EIF3D has been observed to be essential for cell growth in various cancer types, and cancer patients with high EIF3D mRNA levels exhibit poor prognosis, indicating involvement of EIF3D in oncogenesis. In this study, we found, by mass spectrometry, that Cullin-3 (CUL3)/KCTD10 ubiquitin (Ub) ligase forms a complex with EIF3D. We also demonstrated that EIF3D is K27-polyubiquitinated at the lysine 153 and 275 residues in a KCTD10-dependent manner in human hepatocellular carcinoma HepG2 cells. Similar to other cancers, high expression of EIF3D significantly correlated with poor prognosis in hepatocellular carcinoma patients, and depletion of EIF3D drastically suppressed HepG2 cell proliferation. These results indicate that EIF3D is a novel substrate of CUL3/KCTD10 Ub ligase and suggest involvement of K27-polyubiquitinated EIF3D in the development of hepatocellular carcinoma. • EIF3D is a novel substrate of CUL3/KCTD10 ubiquitin ligase. • The ubiquitin code of EIF3D is K27-polyubiquitination at the lysine 153 and 275 residues. • The CUL3/KCTD10/EIF3D axis is essential for proliferation of HepG2 cells. [ABSTRACT FROM AUTHOR]

Esophageal cancer is one of the most malignant tumors in digestive system, but the pathogenesis of esophageal cancer is still unclear. It has been verified that circular RNAs (circRNAs) play critical roles in development and progression of tumors. However, little research concentrates on the role of circRNAs in the pathogenesis of esophageal cancer. In the present study, we found that circular RNA-RAD23B (circRAD23B) was upregulated in specimens of patients with esophageal cancer. Further investigation revealed that circRAD23B promoted proliferation and invasion of esophageal cancer cells. Next, we identified microRNA-5095 (miR-5095) as a target of circRAD23B, and found that miR-5095 was negatively correlated to the expression of circRAD23B in esophageal cancer. In addition, circRAD23B facilitated expression of PARP2 and AKT2 by sponging miR-5095, which might underlie the growth of esophageal cancer. In summary, these data displayed the crucial role of circRAD23B/miR-5095 regulating PARP2 and AKT2 in esophageal cancer, and provided a novel mechanism in the pathogenesis of esophageal cancer. • CircRAD23B is upregulated in esophageal cancer. • CircRAD23B promotes growth of esophageal cancer cells by sponging miR-5095. • PARP2 and AKT2 are downstream of pro-tumor circRAD23B/miR-5095 in esophageal cancer cells. [ABSTRACT FROM AUTHOR]

The biological effects of sevoflurane, a volatile anesthetics, on cancer cells seem to be contradictory and are not fully understood. While some studies demonstrate that sevoflurane promotes tumor growth, other studies report that sevoflurane displays anti-cancer activities. In this work, we systematically investigated the effects of sevoflurane at clinically relevant dose on the multiple biological aspects of cervical cancer cells and analyzed the underlying mechanism. Using a panel of cell lines, we found that sevoflurane significantly inhibited proliferation and migration of cervical cancer cells regardless of cellular origin and genetic background. In contrast, sevoflurane did not affect cervical cancer survival. Additionally, sevoflurane significantly enhanced chemosensitivity of cervical cancer cells. Mechanistically, we show that sevoflurane inhibits Ras and RhoA GTPase activities, leading to the blockade of their downstream signaling pathways, such as Ras/Erk/Akt and Rho/MYPT1/MLC. The rescue studies using Rho activator calpeptin or constitutively active Ras further confirm that Ras and RhoA are the targets of sevoflurane in cervical cancer. Interestingly, we found that the anti-proliferative effect of sevoflurane was via targeting Ras whereas the anti-migratory effect of sevoflurane was mediated via targeting RhoA. Our data clearly demonstrates the anti-cancer effects of sevoflurane. These findings provide preclinical evidence into the potential mechanisms by which sevoflurane may negatively affect cervical cancer growth and metastasis. • Sevoflurane inhibits cervical cancer cell growth and migration but not survival. • Sevoflurane significantly enhances chemosensitivity in cervical cancer cells. • Sevoflurane suppresses multiple oncogenic pathways in cervical cancer cells. • Sevoflurane targets cervical cancer cell through a RhoA- and Ras-dependent manner. [ABSTRACT FROM AUTHOR]

Early malignant transformation of nasopharyngeal carcinoma(NPC) is associated with Epstein-Barr virus(EBV) infection and telomerase activation. The EBV latent membrane protein 1(LMP1) regulates expression of various genes by triggering NF-κB signaling pathway. PINX1 is a well-identified tumor suppressor gene by inhibiting telomerase activity and cancer cell growth. However, whether and how EBV inhibit PINX1 expression and activate telomerase in NPC is still incompletely elucidated. Immunohistochemistry, real-time PCR and Western blotting were utilized to explore the expression of PINX1. Chromatin immunoprecipitation(ChIP) and Dual-luciferase reporter assay were used to elucidate the regulatory mechanism between NF-κB and PINX1. TRAP-SYBR Green assay and Southern blotting were utilized to detect telomerase activity and telomere length. CCK8 and EdU tests were conducted to measure proliferation ability. We demonstrated that PINX1 is down-regulated in NPC for the first time. Mechanistically, we found that LMP1 could inhibit the transcriptional activity of PINX1 by promoting the binding of p65 to three specific sites in PINX1 promoter, significantly, two(-1698/-1689, tgcaatttcc; −206/-197, cgggctttac) of which have not been reported. In addition, we also observed that LMP1 overexpression resulted in increased telomerase activity, prolonged telomere length and enhanced proliferation. We first discovered EBV led to reduced PINX1 expression through LMP1-NF-κB-PINX1 axis, which up-regulated telomerase activity in NPC. And hence, the tumor cells acquired the ability to proliferate more exuberantly. This signaling pathway illustrates the relationship between EBV latent infection and telomerase activation, and further provides new thinking for early diagnosis and treatment in NPC. • The expression of the telomerase inhibitor PINX1 is generally downregulated in nasopharyngeal carcinoma(NPC). • NF-κB inhibits transcription of PINX1 by binding to multiple elements in PINX1 promoter. • The EBV LMP1-NF-κB-PINX1 signal pathway activates telomerase, which exerts an important role in the progression of NPC. [ABSTRACT FROM AUTHOR]

Arachidonate lipoxygenase12 (Alox12) and its metabolites 12S-hydroxyeicosatetraenoic acid (12S-HETE) have been implicated in influencing tumor transformation and progression. In this study, we have systematically evaluated the expression, function and the downstream effectors of Alox12 in breast cancer using loss- and gain-of-function approaches. We demonstrated that both mRNA and protein levels of Alox12 were significantly increased in multiple breast cancer cell lines compared to normal breast cells. The upregulation of Alox12 expression was also observed in breast cancer tissues and their matched normal breast tissues obtained from patients. Functionally, we demonstrated that Alox12 overexpression was sufficient to stimulate growth in normal breast cells but not breast cancer cells. This also protects breast cancer cell from chemotherapy-induced growth arrest and apoptosis. In contrast, Alox12 depletion inhibited breast cancer growth and survival, and significantly enhanced the chemotherapeutic agents' efficacy. Mechanism studies showed that Alox12 depletion activated AMP-activated protein kinase (AMPK), leading to the inhibition of acetyl-CoA carboxylase1 (ACC1) enzyme activity and lipid synthesis. The recuse of the effects of Alox12 depletion using Alox12 metabolites 12S-HETE further confirmed that AMPK and its subsequent inhibition of ACC1 activity and lipid synthesis were the downstream signaling of Alox12 inhibition. Our findings highlighted the important role of Alox12 in breast cancer, particularly in response to chemotherapy. Our work also demonstrate that inhibiting Alox12 is a possible alternative therapeutic strategy to overcome chemoresistance in breast cancer. • Alox12 is aberrantly activated in breast cancer tissues and cells. • Alox12 increases normal breast cell growth and breast cancer cell chemoresistance. • Alox12 depletion negatively affects breast cancer cell. • Alox12 depletion activates AMPK and inhibits lipid synthesis. [ABSTRACT FROM AUTHOR]

Signal transducer and activator of transcription 3 (STAT3), a transcription factor responsive to the activation of cytokine receptors, is known for its oncogenic actions. Whilst STAT3α is the predominant spliceform in most tissues, alternative splicing of the STAT3 gene can generate a shorter STAT3β spliceform. Redirecting splicing to enhance STAT3β levels can result in tumor suppression in vivo , and so we evaluated the cellular basis underlying the anti-tumorigenic properties of STAT3β. To investigate the impact of increased STAT3β levels in cancer cells, we implemented a Morpholino-based antisense oligonucleotide strategy to modulate STAT3 spliceform expression in the MCF10CA1h cancer cells of the MCF10 series of human breast cancer cells. We employed nonsense-mediated decay (NMD) oligonucleotides and STAT3α-to-β expression switching (SWI) oligonucleotides to successfully induce STAT3 knockdown and redirect alternative splicing to increase STAT3β levels in MCF10CA1h cells, respectively. Importantly, assessment of the impacts of STAT3 splicing modulation on tumor cell biology showed that the SWI treatment significantly reduced MCF10CA1h cell growth, viability, and migration, whereas NMD treatment was without significant impact, although neither NMD nor SWI oligonucleotides significantly inhibited MCF10CA1h cell invasion through a semi-solid matrix. In conclusion, our data demonstrate that reduced breast cancer cell growth, viability and migration, but not invasion, follow the redirection of STAT3α-to-β expression switching to favour STAT3β expression. • Morpholino oligonucleotides can induce STAT3 knockdown or splicing switch. • Morpholino-directed STAT3β up-regulation inhibits cell growth and migration. • Morpholino-directed STAT3α knockdown does not impact cell growth or migration. [ABSTRACT FROM AUTHOR]

Whilst effects of anti-cancer drugs have been thoroughly explored, little is known about the repercussion of drug cessation. However, this has important clinical relevance since several clinical protocols such as intermittent drug scheduling lead to frequent drug discontinuation. In this study, we have thus investigated the consequences of withdrawal of agents that target the PI3K/AKT/mTOR signaling pathway in cancer cells. We report that washout of kinase inhibitors of mTOR or PI3K inhibitors led to a rapid and sustainable overactivation of AKT. Consequently, proliferation of tumor cells was significantly higher following drug washout in cancer cells that were pre-treated with mTOR or PI3K inhibitors compared to untreated cells. This effect was prevented by the addition of an AKT inhibitor following drug washout. Rebound AKT overactivation induced by mTOR or PI3K inhibitors discontinuation was mediated by IGF-1R, as demonstrated by its prevention in the presence of an IGF-1R inhibitor and by increased IGF-1R phosphorylation in treated cells versus control cells. Taken together, our results show that discontinuation of PI3K or mTOR inhibitors results in AKT overactivation that promotes tumor growth. They further highlight the benefit of adding an AKT inhibitor following cessation of PI3K or mTOR inhibitors. Image 1 • Discontinuation of PI3K or mTOR inhibitors induces AKT overactivation. • Increased AKT activity following drug washout promotes cancer cell growth. • Targeting AKT following cessation of mTOR or PI3K inhibitors provides anti-cancer benefits. [ABSTRACT FROM AUTHOR]

Endoplasmic reticulum membrane protein complex subunit 6 (EMC6), also known as transmembrane protein 93 (transmembrane protein 93, TMEM93), is an autophagy-related protein. EMC6 overexpression inhibits cancer cell growth and induces apoptosis, but the interaction partners of EMC6 and its cellular responsibilities remain incompletely understood. In this study, we report that adenovirus-mediated ectopic overexpression of EMC6 (Ad5-EMC6) in BGC823 and SGC7901 gastric cancer cells decreases the activity of ERK1/2, down-regulates the levels of BCL-2 protein and phosphorylated BCL-2, increases the expression of tBID and BAX, and decreases mitochondrial membrane potential and subsequently leading to cell apoptosis. In a xenograft tumor model, we found that Ad5-EMC6 impairs the tumorigenesis of SGC7901 gastric cancer cells in nude mice. Additionally, Ad5-EMC6 enhances the sensitivity of gastric cancer cells to the chemotherapeutic drug etoposide. Collectively, these results demonstrate that EMC6-induced apoptosis of gastric cancer cells occurs at least partially through the mitochondrial-mediated apoptosis pathway. Our study suggests a rational basis for the potential clinical application of Ad5-EMC6 in gastric cancer. • Ad5-EMC6 decreases the activity of ERK1/2, down-regulates the levels of BCL-2 and increases the ratio of BAX/BCL-2. • Ad5-EMC6 mediates anti-tumor activity through the mitochondrial apoptosis pathway. • Ad5-EMC6 enhances the sensitivity of gastric cancer cells to the etoposide. [ABSTRACT FROM AUTHOR]

Lung cancer is one of the leading causes of cancer-related death in developed countries. Despite decades of intensive efforts to comate this malignant disease, the prognosis of lung cancer remains unfavorable and is especially poor in advanced non-small cell lung cancer (NSCLC). However, whether and how the m6A demethylase FTO functions in lung cancer cells remain unknown. Here in the present study, we show that FTO plays an oncogenic role in human NSCLC. FTO mRNA and protein levels were overexpressed in human NSCLC tissues and cell lines, which was associated with the reduced m6A content. We next knocked down FTO expression in human lung cancer cell lines with lentivirus-mediated shRNAs and the cellular proliferation assay demonstrated that FTO loss-of-function reduced the proliferation rate of cancer cells. FTO knockdown also inhibited the colony formation ability of lung cancer cells. Importantly, our xenograft experiment showed that FTO knockdown reduced lung cancer cells growth in vivo. Mechanism analysis demonstrated that FTO decreased the m6A level and increased mRNA stability of ubiquitin-specific protease (USP7), which was relied on the demethylase activity of FTO. USP7 mRNA level was overexpressed in human lung cancer tissues and USP7 expression was positively correlated with FTO mRNA level. Genetic knockdown or pharmacological inhibition (P5091 or P22027) of USP7 reduced the proliferation rate of lung cancer cells and decreased the capacity of colony formation of lung cancer cells in vitro, whereas lung cancer cells growth inhibition by FTO knockdown is restored by overexertion of USP7. Collectively, our findings demonstrate that the m6A demethylase FTO promotes the growth of NSCLC cells by increasing the expression of USP7. Image 10667 • Expression of FTO is increased in human non-small cell lung cancer. • FTO knockdown represses lung cancer cells growth in vitro and in vivo. • FTO regulates the expression of USP7 in lung cancer cells. • USP7 regulates the growth of lung cancer cells. [ABSTRACT FROM AUTHOR]

Abstract Gastric cancer (GC) is a common malignancy. Developing novel and efficient anti-GC agents is urgent. GSK1059615 is a PI3K (phosphatidylinositol 3-kinase) and mTOR (mammalian target of rapamycin) dual inhibitor. It activity in human GC cells is tested here. In AGS cells and primary human GC cells, GSK1059615 potently inhibited cell growth, survival, proliferation and cell cycle progression. Further, significant apoptosis activation was detected in GSK1059615-treated GC cells. Contrarily in the primary human gastric epithelial cells, GSK1059615 failed to induce significant cytotoxicity and apoptosis. GSK1059615 blocked PI3K-AKT-mTOR cascade activation, inducing microRNA-9 downregulation but LMX1A (LIM homeobox transcription factor 1α) upregulation in GC cells. Significantly, GSK1059615 administration (i.p., daily, at 10 or 30 mg/kg) in nude mice potently inhibited subcutaneous AGS xenograft growth. AKT-mTOR inhibition and LMX1A upregulation were detected in AGS xenograft tissues with GSK1059615 administration. Together, we conclude that GSK1059615 inhibits GC cell growth in vitro and in vivo. Highlights • GSK1059615 inhibits GC cell growth, survival, proliferation and cell cycle progression. • GSK1059615 induces apoptosis activation in GC cells. • GSK1059615 blocks PI3K-AKT-mTOR and changes miR-9- LMX1A expression in GC cells. • GSK1059615 administration inhibits subcutaneous AGS xenograft growth in nude mice. [ABSTRACT FROM AUTHOR]

Abstract Non-small cell lung cancer (NSCLC) is an aggressive malignancy with poor clinical outcomes. Accumulating evidence indicated that dysregulation of circular RNAs (circRNAs) plays a key role in multiple solid tumors. In this study, circ-RAD23B was explored. The expression of circ-RAD23B in NSCLC was detected by RT-qPCR. The clinical value of circ-RAD23B was analyzed by Fisher's exact test and Kaplan-Meier curves. Gain and loss of function experiments were carried out to elucidate the biological functions of circ-RAD23B in NSCLC cell lines. Dual luciferase reporter assay and rescue experiments were used to reveal the mechanism of circ-RAD23B. The findings demonstrated that circ-RAD23B, identified to be amplified and overexpressed in NSCLC, was associated with lymph node invasion, lower differentiation grade and shorter overall survival (OS). Furthermore, circ-RAD23B functions as an oncogene in NSCLC cells. Mechanistically, circ-RAD23B could sponge miR-593–3p and miR-653–5p and thus elevate CCND2 and TIAM1 expression, respectively. Rescue assays proved that circ-RAD23B promotes cell growth via miR-593–3p/CCND2 axis and facilitates cell invasion by miR-653–5p/TIAM1 pathway. Taken together, we propose circ-RAD23B as a promising biomarker and therapeutic target for NSCLC. Highlights • Circ-RAD23B is upregulated in NSCLC tissues and cells. • Circ-RAD23B expression is associated with NSCLC patients' clinical severity. • Circ-RAD23B exerts oncogenic properties in NSCLC cells. • Circ-RAD23B could sponge miR-593–3p and miR-653–5p and thus elevate CCND2 and TIAM1 expression, respectively. • Circ-RAD23B promotes cell growth via miR-593–3p/CCND2 axis and facilitates cell invasion by miR-653–5p/TIAM1 pathway. [ABSTRACT FROM AUTHOR]

Abstract ETS1 (E26 transformation specific-1) is the founding member of ETS transcriptional factor family. It transcriptionally modulates numerous gene expressions, and is involved in cellular differentiation, tissue remodeling, angiogenesis, drug resistance and tumorigenesis. ETS1 is usually regarded as an oncogene. However, its apoptosis-inducing activity was also frequently reported. Here, we identified RYBP (Ring1 and YY1 binding protein), a critical epigenetic regulator and apoptosis enhancer, as a novel transcriptional target of ETS1. Specifically, we found that overexpression of ETS1 up-regulates the promoter activity of RYBP in HEK293T and tumor cells from different tissue origins, indicating a universal transcriptional regulatory effect. Subsequently, both overexpression and RNA interfering experiments demonstrated that ETS1 positively modulates RYBP expression from both mRNA and protein levels. Bioinformatics analysis combined with site-directed mutagenesis suggested that there probably exist a multiple of ETS1 binding sites in RYBP promoter region, and chromatin immunoprecipitation assay validates the physical association between ETS1 protein and RYBP promoter region. Functional studies showed that ectopic expression of ETS1 significantly suppresses tumor cell proliferation. However, this inhibitory effect was partially compromised when RYBP was concomitantly knocked down by its specific short hairpin RNA. Meanwhile, we provide evidence to demonstrate that cyclin-dependent kinase inhibitor p21 is possibly involved in this regulatory loop. Taken together, our current study identified RYBP as a new transcriptional target which is utilized by ETS1 to carry out its tumor cell growth inhibitory effect. Highlights • ETS1 up-regulates human RYBP expression at transcriptional level. • ETS1 binds to RYBP promoter region through a multiple of conserved ETS1 binding sites in RYBP promoter region. • RYBP is required for ETS1-induced human tumor cell growth inhibition. [ABSTRACT FROM AUTHOR]