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The development and progression of hepatocellular carcinoma (HCC) is associated with the presence of cancer stem cells (CSCs). In the present study, kinesin family member 15 (KIF15) expression was shown to be overexpressed in HCC tissues, cell lines, and CSCs. Patients with HCC with high KIF15 expression had shortened overall survival (OS) and high recurrence probability. Downregulation of KIF15 in vitro as well as in HCC organoids resulted in a significant reduction in sphere formation and expression of stemness-related genes. KIF15 downregulation in human HCC xenograft models delayed tumor initiation, growth, and metastasis. KIF15 was also demonstrated to interact with phosphoglycerate dehydrogenase (PHGDH) and inhibit proteasomal degradation of PHGDH, thus promoting CSC phenotype and malignancy via PHGDH-mediated intracellular reactive oxygen species (ROS) imbalance in HCC. Moreover, AAA nuclear coregulator cancer-associated protein (ANCCA) upregulation acts as a key mediator in KIF15 expression upregulation in HCC. Conclusion: In this study, we found that KIF15 promotes the CSC phenotype and malignancy via PHGDH-mediated ROS imbalance in HCC. These findings highlight potential therapeutic targets for HCC.

Cancer persists as a worldwide disease that contributes to high morbidity and mortality rates. As a class of non-coding RNA, microRNAs (miRNAs) are one kind of important regulators in cancer and frequently implicated in tumor development and progression. Emerging experiments have suggested that miRNA-195-5p (miR-195-5p) can regulate neoplastic processes in many pathways. For instance, miR-195-5p can not only regulate proliferation, migration and invasion of tumor cells but also promote tumor cell apoptosis. Furthermore, low expression of miR-195-5p could induce drug resistance. Our review focuses on the expression of miR-195-5p in various tumors and elucidates the related mechanisms of which miR-195-5p participates in tumor biology, as well as summarizes the roles of miR-195-5p in tumor progression. We believe that miR-195-5p might have potential utility as a novel diagnostic biomarker and therapeutic target for cancer.

Radioresistance remains to be a major obstacle in the management of patients with advanced prostate cancer (PCa). We have identified a mature miR-17-3p processed from the 3′ arm of precursor miR-17, which appeared to be able to inhibit three major antioxidant enzymes located in mitochondria, i.e., manganese superoxide dismutase (MnSOD), glutathione peroxidase 2 (Gpx2), and thioredoxin reductase 2 (TrxR2). Here we show that upregulation of miR-17-3p remarkably sensitized PCa cells to ionizing radiation (IR). Reductions of the three antioxidants led to increasing cellular reactive oxygen species (ROS) accumulation as well as declining mitochondrial respiration. The miR-17-3p-mediated dysfunction of mitochondrial antioxidants apparently sensitizing IR therapy was manifested in vitro and in vivo. Substantially, the miR-17-3p effect on suppression of the antioxidants can be efficiently eliminated or attenuated by transfecting with either an miR-17-3p inhibitor or each of the related antioxidant cDNA expression constructs. Overall, in addition to the insights into the functional assessments for the duplex of miR-17-5p and miR-17-3p, the present study highlights the rigorous evidence that demonstrated suppression of multiple mitochondrial antioxidants by a single microRNA (miRNA), thereby providing a promising approach to improve radiotherapy for advanced PCa by targeting mitochondrial function. Keywords: miR-17-3p, antioxidant enzymes, reactive oxygen species, radiosensitivity, prostate cancer

Objectives Accumulating evidence has been reported that circular RNAs (circRNAs) are a class of relatively stable, non-coding RNAs, which are involved in the progression of many types of diseases. However, the mechanism of hsa_circ_0052112 in breast cancer cells is not entirely clear. Hsa_circ_0052112, generated from the ZNF83 gene, is selected by analyzing circRNA expression profiles of breast cancer cell by using microarray assay. In this study, we will show the role of hsa_circ_0052112 in regulating cell invasion and migration in breast cancer. Methods The expression level of hsa_circ_0052112 in MCF-7 and MDA-MB-231 cells was detected by RT-qPCR; we performed transwell assay to evaluate breast cancer cells’ migration and invasion; predicated circRNA/miRNAs interaction using the miRanda and RNAhybrid software; identified the relationship between hsa_circ_0052112 and miR-125a-5p by luciferase activity assay and show the localization of hsa_circ_0052112 by FISH assay and show the significance of ZNF83 in clinical prognosis by Kaplan-Meier survival analysis. Results Hsa_circ_0052112 expression was significantly higher in MDA-MB-231 cells than that in MCF-7 cells. Overexpression of hsa_circ_0052112 promoted cell migration and invasion in breast cancer. Inversely, down-regulation of hsa_circ_0052112 suppressed breast cancer cells migration and invasion. Hsa_circ_0052112 was mostly located in cytoplasm. Hsa_circ_0052112 could directly sponge to miR-125a-5p; overexpression of miR-125a-5p significantly inhibited breast cancer cells migration and invasion. However, high or low expression of miR-125a-5p was not correlated with relapse free survival (RFS) by TCGA database validation, but high expression of ZNF83 was closely correlated with poor RFS by Kaplan–Meier plotter. Conclusions These data suggest that hsa_circ_0052112 may be a potent biomarker for breast cancer, and may provide a new perspective on treatment of breast cancer.

The subtypes of distant-organ metastasis led to treatment failure and poor prognosis are major obstacles in the management of patients with advanced breast cancer (BCa). Emerging evidences demonstrated that exosomes act as mediators for intercellular communication between various types of cells in the local tumor microenvironment. The present study aims to investigate whether BCa-derived exosomes are capable of cell-cell transferring miR-222 for BCa metastatic progression. Results showed that exosomal miR-222 is highly expressed in BCa patients with lymphatic metastasis. Consistently, the elevated levels of exosomal miR-222 are closely correlated with the high aggressivity of BCa cell lines. miR-222 promoting the aggressivity of BCa cells was confirmed in vitro and in vivo. Mechanistically, miR-222 directly targets PDLIM2, a tumor suppressor gene, leading to activation of NF-κB signal pathway. In conclusion, the levels of exosomal miR-222 are correlated with BCa metastatic progression. Exosome-transferred miR-222 promotes migration and invasion of BCa cells. miR-222 contributes to tumorigenicity of BCa cells through down-regulation of PDLIM2 and consequently activating NF-κB.

Background and purpose Acquisition of resistance to adriamycin (ADR) is one of the most important clinical obstacles in the treatment of breast cancer, but the molecular mechanisms underlying sensitivity to ADR remain elusive. In our previous study, through miRNA microarray and experiments, we have emphasized that miR-222 could promote the ADR-resistance in breast cancer cells. The aim of this study was to explore the possible mechanism by which miR-222 affects sensitivity to ADR. Methods Through pathway enrichment analyses for miR-222, we found that PTEN/Akt/FOXO1 signaling pathway may be of importance. RT-qPCR analyses and western blot assays confirmed the relationship between miR-222 expression and target genes. Immunofluorescence further visually displayed the location of FOXO1. When blocking PTEN/Akt/FOXO1 signaling pathway, we demonstrated the effects of miR-222-mediated ADR resistance by MTT and apoptosis assays. Results RT-qPCR and Western blot results showed that miR-222 expression was negatively correlated with FOXO1 expression. In addition, the subcellular translocation of FOXO1 due to the altered expression of miR-222 was observed from immunofluorescence. Moreover, upregulation of miR-222 expression in MCF-7/S cells is associated with decreased PTEN expression levels and increased phospho-Akt (p-Akt) expression. Conversely in MCF-7/ADR cells, inhibition of miR-222 resulted in increased PTEN expression and decreased p-Akt expression. For further validation, results of the present study also demonstrated that PTEN/Akt/FOXO1 signaling was responsible for the ADR-resistance of breast cancer cells since LY294002, an inhibitor of Akt signaling, partially increased the sensitivity of MCF-7/S cells to ADR. More importantly, we postulated that high expression of miR-222 is closely related to poor overall survival by TCGA database validation. Conclusions Taken together, these data elucidated that miR-222 mediated ADR-resistance of breast cancer cells partly through regulation of PTEN/Akt/FOXO1 signaling pathway and inhibition of miR-222 may improve the prognosis of breast cancer patients.

Purpose Acquisition of resistance to adriamycin (ADR) during the treatment of breast cancer is still a major clinical obstacle. MicroRNAs (miRNAs) are a class of short noncoding RNAs which associate with cancer chemoresistance through regulating gene expression by targeting mRNAs. Our previous microarray found that miR-29a may strongly confer the ADR resistance of breast cancer cells. Here, we aim to explore the possible mechanism by which miR-29a affects sensitivity to ADR. Methods ADR-resistant MCF-7 breast cancer cell subline (MCF-7/ADR) was successfully established in vitro through a stepwise increase of ADR concentrations in the culture based on parental MCF-7 cell lines (MCF-7/S). We used TargetScan (a wide use of target prediction algorithms) in conjunction with pathway enrichment analyses to predict the mRNAs that were most likely to involve in miR-29a-mediated drug resistance in cancers. We confirmed the effects of miR-29a-mediated ADR resistance through MTT and apoptosis assays, and further investigated the activities of two target genes, PTEN and GSK3β, by RT-qPCR analyses and western blot assays. Results The expression level of miR-29a in MCF-7/ADR cells was remarkablely higher than in MCF-7/S cells. Further MTT and apoptosis assays revealed that transfection of miR-29a inhibitors into MCF-7/ADR cells resulted in prominent reduction of the drug resistance, in contrast, transfection of miR-29a mimics into MCF-7/S cells obviously increased their drug resistance. Through pathway enrichment analyses for miR-29a, we found that PTEN/AKT/GSK3β signaling pathway may be of importance. RT-qPCR and Western blot results showed that downregulation of miR-29a expression in MCF-7/ADR cells increased PTEN expression levels, resulting in decreased phospho-Akt (p-Akt) and phospho-GSK3β (p-GSK3β) expression. Conversely, upregulation of miR-29a expression in MCF-7/S cells is associated with decreasing PTEN expression and increasing p-Akt and p-GSK3β expression. Conclusions PTEN and GSK3β are targeted by miR-29a, and miR-29a may contribute to ADR resistance through inhibition of the PTEN/AKT/GSK3β pathway in breast cancer cells. Thus, miR-29a may be a potential target for the patients who acquired ADR-resistance during the treatment of breast cancer.

microRNAs (miRNAs) are small noncoding RNAs that could regulate post-transcription level through binding to 3' untranslated region (3'UTR) of target messenger RNAs (mRNAs), which were reported to be related with the incidence and development of diverse neoplasms. Among them, miR-197 was confirmed to play a vital role of oncogene or anti-oncogene in different cancers via targeting key tumorigenic or tumor-suppressive genes. Additionally, miR-197 had extensively been studied in carcinogenesis progression of cancers through various mechanisms, including apoptosis, proliferation, angiogenesis, metastasis, drug resistance and tumor suppressor, and also played a role in prognosis of cancers. In this review, we summarized the roles of miR-197 in cancers and considered it as a potentially novel biomarker for different cancers, offering an alternatively secure and effective tool in molecular targeting cancer treatment.

Adriamycin (Adr) is a potent chemotherapeutic agent for chemotherapy of breast cancer patients. Despite impressive initial clinical responses, some developed drug resistance to Adr-based therapy and the mechanisms underlying breast cancer cells resistance to Adr are not well known. In our previous study, in vitro, we verified that miR-222 was upregulated in Adr-resistant breast cancer cells (MCF-7/Adr) compared with the sensitive parental cells (MCF-7/S). Here, miR-222 inhibitors or mimics were transfected into MCF-7 cell lines. RT-qPCR and western blot were used to detect the expression of p27(kip1). Immunofluorescence showed that miR-222 altered the subcellular location of p27(kip1) in nucleus. MTT was employed to verify the sensitivity of breast cancer cell lines to Adr. Flow cytometry showed the apoptosis and cell cycles of the cells after adding Adr. The results showed that downregulation of miR-222 in MCF-7/Adr increased sensitivity to Adr and Adr-induced apoptosis, and arrested the cells in G1 phase, accompanied by more expressions of p27(kip1), especially in nucleus. Furthermore, overexpressed miR-222 in MCF-7/S had the inverse results. Taken together, the results found that miR-222 induced Adr-resistance at least in part via suppressing p27(kip1) expression and altering its subcellular localization, and miR-222 inhibitors could reverse Adr-resistance of breast cancer cells. These results disclosed that the future holds much promise for the targeted therapeutic in the treatment of Adr-resistant breast cancer.

Background Tumor-associated macrophages (TAMs) constitute over 50% of the number of cells in breast malignancies. In mouse models, most TAMs in the breast cancer microenvironment behave as the M2-like phenotype, with protumor characteristics, but the roles of TAMs in human breast cancer are poorly understand. Specific TAMs related molecular mechanisms among different intrinsic molecular subtypes remain unclear. Here, we focused on studying protumor TAM markers among human breast cancer tissues: CD163, CD204, CD206 which commonly used in mouse models. We identify and explore roles of TAMs novel marker: CD204 in intrinsic molecular subtypes of breast cancer. Methods Expression of CD204, CD163, CD206 and clinical outcome of CD204 were analyzed using The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets. Potential Kyoto Encyclopedia of Genes and Genomes (KEGG) and HALLMARK pathways regulated by CD204 were studied using Gene Set Enrichment Analysis (GSEA). We used CIBERSOT to estimate the immune contextures regulated by CD204 among different subtypes and the correlations of CD204 and immune suppressive molecules were also analyzed. Results Compared to CD163, CD206, only CD204 was found upregulated in breast cancer compared to the normal tissue, associated with poor OS, RFS, and DMFS. The expression of CD204 was different between 4 subtypes. CD204 was involved in immune system-related pathways including innate and adaptive immunity among all subtypes. Numerous special pathways were also found influenced by CD204: tumor metabolism-related pathways in luminal A, Hippo and TGF-β signaling pathways in luminal B, cell cycle process in HER-2 amplified, and RIG-I-like receptor signaling pathway in basal-like subtype. Strong correlations between CD204 and immune cells especially for protumor populations were displayed, and most immunosuppressive molecules: HIF1A, FAP, IL10, PDCD1/CD274, CTLA4, HAVCR2, positive correlated with CD204 expression in all subtypes. Conclusions CD204 could become an applicable marker of TAMs in human breast cancer. These findings contribute to better understanding and managing of TAMs in different subtypes of breast cancer. Legal entity responsible for the study Jinhai Tang. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.

Objectives MiRNA-139 is located at 11q13.4 and it has anti-oncogenic and antimetastatic activity in humans. However, its role in controlling apoptosis, invasion and metastasis and the development of chemosensitivity to docetaxel in breast cancer cells are not fully understood. The aim of this study was to research the biological function of miR-139-5p and the efficacy of chemosensitivity to docetaxel. Methods MiR-139-5p expression in MCF-7, MCF-7/Doc cells and in selected breast cancer tissue samples was confirmed by real-time PCR; cell viability was analyzed by Cell Counting Kit-8 assay; apoptosis and cell cycle were analyzed by flow cytometry; control of metastasis and invasion of breast cancer cells was measured by transwell assay; expression of Notch1 was measured by western blot; a luciferase reporter vector was constructed to identify the miR-139-5p target gene. Results MiR-139-5p was significantly down-regulated in breast cancer cells. MiR-139-5p inhibits the viability of breast cancer cells. MiR-139-5p induces apoptosis, causes cell cycle arrest in S phase, inhibits migration and invasion in breast cancer cells, however, MiR-139-5p play the opposite role in docetaxel-induced breast cancer cells. Conclusions MiR-139-5p not only attenuated the development of breast cancer cells but also mediated drug-resistance by regulating the expression of the downstream target gene Notch1.

Objectives The purpose of this study was to investigate the relationship between huntingtin-associated protein1 (HAP1) gene and radiation therapy of breast cancer cells. Methods HAP1 gene was transfected into breast cancer MCF-7 cells, which was confirmed by quantitative reverse transcription-polymerase chain reaction analysis (qRT-PCR) and Western blot in vitro. The changes of cell radiosensitivity were assessed by colony formation assay. Apoptosis were examined by flow cytometry. The expressions of two radiation-induced genes were evaluated by Western blot. Tumor growth was investigated in nude mice xenograft models in vivo. Results Our data showed that HAP1 gene expression was significantly increased in HAP1-transfected MCF-7 cells in comparison with the parental cells or negative control cells. The survival rate in MCF-7/HAP1 cells was significantly decreased after irradiation (0, 2, 4, 6, 8 Gy), compared to cells in MCF-7 and MCF-7/Pb groups in vitro. HAP1 gene increased apoptosis in MCF-7 cells after irradiation. Additionally, the tumor volume and weight in MCF-7/HAP1 + RT group were observably lower than in MCF-7/HAP1 group and MCF-7/Pb + RT group. Conclusion The present study indicated that HAP1 gene expression was related to the radiosensitivity of breast cancer cells and may play an important role in the regulation of cellular radiosensitivity.

Background Anthracycline/taxane-based chemotherapy is frequently used to treat breast cancer. However, not all patients respond to chemotherapy due to naturalor acquired chemo-resistance. Glutathione S-transferase P1(GSTP1), which belongs to the family of phase II metabolic enzymes, has been reported to function in detoxifying several anti-cancer drugs by conjugating them with glutathione. Methods We identified GSTP1 as a drug-resistance-related factor by microarray. Then, we used cell apoptosis and immunofluorescence staining to confirm the ability of GSTP1-containing exosomes in conferring drug resistance. And the knockdown of GSTP1 gene was performed to found the influence of drug-resistance. Furthermore, the role of GSTP1 and its relationship with exosomes was proved by analysed 40 pairs of breast cancer tissues by IHC. Then, the levels of GSTP1 in serum exosomes were detected in 28 patients treated with neoadjuvant chemotherapy(NAC). Results By microarray data, we found that GSTP1, which located in extracellular exosome, is higher in Adriamycin(ADR)-resistant cell line compared with its parental cell line. Then, we also confirmed a higher expression of GSTP1 protein in ADR-resistant cells by immunofluorescence staining and western blot. Moreover, the addition of GSTP1-containing exosomes can increase the resistance to ADR in sensitive cells. Also, we found that a higher expression GSTP1 in the PD/SD group than in the PR/CR group in 40 paired samples collected before and after chemotherapy. Similar results were obtained for the exosomal marker tumor susceptibility gene 101 protein (TSG101), which also increased in the cytoplasm after chemotherapy. We further explored the levels of GSTP1 in serum exosomes of 28 patients treated with anthracycline/taxane-based NAC, and discovered that the levels of GSTP1 in exosomes from patients in the PD/SD group were higher than those in the PR/CR group. Conclusions GSTP1-containing exosomes appeared to be essential in conferring resistance to anti-cancer drugs. We explored the predictive role of GSTP1 in circulating exosomes as a biomarker for chemo-sensitivity in patients treated with anthracycline/taxane-based chemotherapy. Legal entity responsible for the study Jinhai Tang. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.