Search

Prostate cancer (PCa) is one of the most commonly diagnosed urological malignancies. However, there are limited therapies for PCa patients who develop biochemical recurrence after androgen deprivation therapy (ADT). In the present study, we investigated the therapeutic efficacy and mechanism of α-Viniferin (KCV), an oligostilbene of trimeric resveratrol, against human PCa cells and found that it markedly inhibited the proliferation of LNCaP, DU145, and PC-3 cancer cells in a time- and dose-dependent manner, and had a strong cytotoxicity in non-androgen-dependent PCa cells. In addition, KCV inhibited AR downstream expression in LNCaP cells, and inhibited activation of GR signaling pathway in DU145 and PC-3. Further investigation indicated that KCV could induce cancer cell apoptosis through AMPK-mediated activation of autophagy, and inhibited GR expression in castration-resistant prostate cancer(CRPC). These findings suggest that KCV may prove to be a novel and effective therapeutic agent for the treatment of CRPC.

Bromodomains and extra-terminal (BET) proteins inhibitors are promising cancer therapeutic agents. However, tumor cells often develop resistance to BET inhibitors, greatly limiting their therapeutic potential. To study the mechanism underlying the resistance of BET inhibitors in hepatocellular carcinoma (HCC) cells, we herein investigated the impact of BET inhibitor JQ1 on the gene expression of Bcl-2 family members by RNA sequencing analysis, and found that acute treatment with JQ1 triggered upregulation of Mcl-1 in HCCLM3 and BEL7402 cell lines. This JQ1-triggered Mcl-1 upregulation was further confirmed by quantitative reverse transcription polymerase chain reaction and western blotting analysis, both at mRNA and protein levels. Inhibition of Mcl-1 by RNA interference dramatically enhanced JQ1-triggered caspase-3 activation, cleavage of poly (ADP-ribose) polymerase and apoptotic cell death induction in multiple HCC cell lines. Moreover, JQ1 in combination with cyclin-dependent kinase inhibitor flavopiridol at a subtoxic concentration that reduced expression of Mcl-1, triggered massive apoptotic cell death in HCCLM3 and BEL7402 cell lines. Together, these data suggest that Mcl-1 is a major contributor to BET inhibitor-resistance in HCC cells, and that combining drugs capable of down-regulating Mcl-1 may promote therapeutic potential in human HCC., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Berberine (BBR) is an isoquinoline alkaloid isolated from Cotridis rhizoma and exhibits multiple biological roles including anti-microbe, anti-inflammation and anti-tumor activities. In this study, two triple-negative breast cancer cell (TNBC) lines, MDA-MB-231 and BT549, were used to investigate the effect of BBR on growth of TNBC in vitro and in vivo. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to evaluate the viability of cells treated with BBR. After 48h treatments, a 50% inhibitory concentration (IC 50 ) of BBR to BT549 and MDA-MB-231 cells are at 16.575±1.219μg/ml and 18.525±6.139μg/ml respectively. BBR reduced colony formation of BT549 and MDA-MB-231 cells. The wound-healing assay showed BBR decreased breast cancer cell migrations (P<0.01). AnnexinV-PI staining assay confirmed BBR induced cellular apoptosis. The expressions of caspase-3, caspase-9, Bcl-2 and Bax were detected by western blot, which showed BBR activated caspase-3, 9 and Bax, but down-regulated Bcl-2 expression. BBR promoted the release of cytochrome c through the immunofluorescent analysis (P<0.01). We also found BBR increased the level of cellular γH2AX and increased the expression of Ligase4, which suggests BBR induces the double-strand breaks (DSB). These results thus demonstrated that BBR induced DSB, subsequently increased the release of cytochrome c and eventually triggered the caspase9-dependent apoptosis. In addition, we used a MDA-MB-231 mouse-xenograftmodel to evaluate the effect of BBR on tumor growth. BBR suppressed tumor growth and increased caspase-9 levels in xenograft tumors through immunohistochemistry analysis (P<0.01). Taken together, these results demonstrate that BBR activates caspase-9/cytochrome c-mediated apoptosis to inhibit the growth of TNBC breast cancer cells in vitro and in vivo., (Copyright © 2017. Published by Elsevier Masson SAS.)

Objective: To investigate the effect of Bcl-2 overexpression on Fas and TNFR1-mediated apoptosis and its possible mechanism in rat hippocampus following global ischemia/reperfusion (IR)., Methods: Ninety healthy male SD rats were randomly divided into sham operated group, IR group and Bcl-2 overexpression group (BT group). Rat model of global IR was established by the 4-V0 method. The expressions of Bcl-2, Fas and TNFR1 and the cell apoptosis in the CA1 and CA3 regions were examined by HE staining, immunohistochemistry and TUNEL method., Results: In IR group, the neurons in the CA1 region showed an obvious reduction in number with disordered arrangement and interstitial edema 48 h after global IR. Such changes were not obvious in BT group. Immunohistochemistry showed that Fas expression in the CA1 region reached the peak level at 6 h in IR group with a greater expression intensity than that in BT group (P<0.05). TNFR1 was expressed at a higher level in IR group than in BT group (P<0.05), reaching the peak level at 24 h. In the sham group, the expression of Fas and TNFR1 was not detected the in CA1 and CA3 regions. Global IR caused increased cell apoptosis in the CA1 and CA3 regions, starting at 6 h and reached peak at 24 to 48 h. The cell apoptosis was less obvious in BT group (P<0.05)., Conclusion: Fas and TNFR1 are expressed in the CA1 and CA3 regions after global IR in rats, suggesting the involvement of death receptor in cerebral IR injury. Bcl-2 overexpression decreases the expression of Fas and TNFR1 and cell apoptosis after global IR, thus offering protective effect against cerebral IR injury.

Pyroptosis is an inflammatory form of programmed cell death that is involved in various cancers, including hepatocellular carcinoma (HCC). Long non-coding RNAs (lncRNAs) were recently verified as crucial mediators in the regulation of pyroptosis. However, the role of pyroptosis-related lncRNAs in HCC and their associations with prognosis have not been reported. In this study, we constructed a prognostic signature based on pyroptosis-related differentially expressed lncRNAs in HCC. A co-expression network of pyroptosis-related mRNAs–lncRNAs was constructed based on HCC data from The Cancer Genome Atlas. Cox regression analyses were performed to construct a pyroptosis-related lncRNA signature (PRlncSig) in a training cohort, which was subsequently validated in a testing cohort and a combination of the two cohorts. Kaplan–Meier analyses revealed that patients in the high-risk group had poorer survival times. Receiver operating characteristic curve and principal component analyses further verified the accuracy of the PRlncSig model. Besides, the external cohort validation confirmed the robustness of PRlncSig. Furthermore, a nomogram based on the PRlncSig score and clinical characteristics was established and shown to have robust prediction ability. In addition, gene set enrichment analysis revealed that the RNA degradation, the cell cycle, the WNT signaling pathway, and numerous immune processes were significantly enriched in the high-risk group compared to the low-risk group. Moreover, the immune cell subpopulations, the expression of immune checkpoint genes, and response to chemotherapy and immunotherapy differed significantly between the high- and low-risk groups. Finally, the expression levels of the five lncRNAs in the signature were validated by quantitative real-time PCR. In summary, our PRlncSig model shows significant predictive value with respect to prognosis of HCC patients and could provide clinical guidance for individualized immunotherapy. [ABSTRACT FROM AUTHOR]

Gastric cancer is a common malignant cancer, which is one of the most affected cancers by PI3K/AKT signaling. Here, we investigated the anti‐tumor role of Astragalin, a natural flavonoid compound, in gastric cancer and explored the underlying molecular mechanism. Three well‐established gastric cancer cell lines and xenograft mouse model were used to examine the anti‐tumor effect of Astragalin by using CCK‐8, transwell assays, and Western blot. Tumor burden of xenograft mice with Astragalin administration was monitored and determined during and at end of the experiments. Astragalin could effectively inhibit cell viability of gastric cancer cells and possessed good anti‐tumor activity in xenograft mice. In addition, astragalin induced the expression of apoptotic signaling proteins, suppressed the migration and invasion cancer cells, and inhibited the PI3K/AKT signaling pathway significantly. In contrast, epidermal growth factor stimulation was able to block the anti‐tumor activity of Astragalin. In conclusion, astragalin exerts its anticancer activities through inhibiting PI3K/AKT signaling, which highlights its potential for the treatment of gastric cancer. [ABSTRACT FROM AUTHOR]

Background: Curcumol was presented to unleash antitumor effects in a variety of cancers, including gastric cancer. However, the relevance between curcumol and cisplatin resistance in gastric cancer still remains unclear. Therefore, the current research was performed to survey the role of curcumol in cisplatin sensitivity in gastric cancer. Methods: First, BGC‐823 and BGC‐823/DDP cells were incubated with cisplatin for 48 hr and 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2‐H‐tetrazolium bromide (MTT) analysis was applied to determine the inhibition rate of cell proliferation and the half‐maximal inhibitory concentration (IC50) of cisplatin. In addition, BGC‐823 and BGC‐823/DDP cells were treated with curcumol for 48 hr followed with detection of cell viability and apoptosis using MTT and flow cytometry assay, respectively. Moreover, MTT analysis was applied to test the effects of curcumol on cisplatin sensitivity in gastric cancer cells. Lastly, Western blot assay and qRT‐PCR analysis were utilized to check the functions of curcumol on PI3K/AKT pathway‐related markers. Results: We found that BGC‐823/DDP cells exhibited stronger resistance to cisplatin compared with BGC‐823 cells. Furthermore, curcumol evidently reduced cell proliferation and facilitated cell apoptosis in BGC‐823/DDP and BGC‐823 cells. Moreover, results from MTT assay demonstrated that curcumol notably promoted the suppression effect of cisplatin and decreased the IC50 of cisplatin in BGC‐823/DDP and BGC‐823 cells. It was also presented that curcumol suppressed the PI3K/AKT pathway dose‐dependently in BGC‐823/DDP and BGC‐823 cells. Conclusion: The findings in the current research demonstrated that curcumol could promote the sensitivity of gastric cancer cells to cisplatin‐based chemotherapies via inhibiting the phosphatidylinositol 3‐kinase (PI3K)/Protein Kinase B (AKT) pathway. [ABSTRACT FROM AUTHOR]

Ginkgolic acids may induce malignant cell death via the B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax)/Bcl-2 apoptosis pathway. Concurrently, apoptosis, autophagy and mitochondrial dysfunction may also be involved in bringing about this endpoint. The anticancer effect of Ginkgolic acids (GAs) was investigated using the HepG2 cell line. The median lethal dose of the GAs of the HepG2 was measured via an MTT assay, the dose-response curves were evaluated and changes in cell morphology were monitored by microscopy. Autophagy in HepG2 cells was down regulated using 3-methyladenine (3-MA) or Beclin-1-specific small interfering RNA (siRNA) and the expression of apoptosis associated proteins caspase-3, Bax/Bcl-2, and the autophagy-associated protein 5 and microtubule-associated protein 1A/1B-light chain 3 in the GA-treated HepG2 cells were all measured by western blot analysis. The level of apoptosis in the GA-treated cells was also assessed using terminal deoxynucleotidyl-transferase-mediated dUTP nick-end labeling (TUNEL) assay, and the mitochondrial membrane potential (Δψm) was detected by immunofluorescence. The results of the MTT and TUNEL assays indicated that the proliferation of HepG2 cells treated with GAs was signifi- cantly reduced compared with the control group, and the rate of the inhibition was dose-dependent. Western blot analysis indicated that treatment with the Gas induced apoptosis and autophagy in the HepG2 cells. The Δψm of the GA-treated HepG2 cells was decreased compared with the control, as monitored by immunofluorescence. However, upon the administration of 3-MA or Beclin-1-specific siRNAs (inhibitors of the autophagy), the expression levels of the apoptosis- and autophagy-associated proteins were decreased. In conclusion, the results of the present study indicated that GAs are potent anticancer agents that function through a combination of the apoptosis, autophagy and mitochondrial pathways. [ABSTRACT FROM AUTHOR]

Curcumin is a natural compound isolated from the rhizome of Curcuma longa . It possesses anti-tumor activity through arresting cell cycles and promoting cell apoptosis. However, the effect of curcumin on DNA damage is not well defined. In this study, we investigated the effect of curcumin on inducing DNA damage and on sensitizing lymphoma cells to anti-tumoral DNA damage drugs. Western blot showed curcumin induced γ-H2AX foci in CH12F3 lymphoma cells, which suggests curcumin induces DNA breaks. In addition, curcumin decreased the expression of Rad51, which suggests curcumin induces DNA damage through regulating Rad51-dependant homologous recombination. Rad51-dependant homologous recombination is a vital DNA repair pathway for cancer cells to resist anti-tumoral DNA damage drugs, therefore, we studied the effect of curcumin on the sensitizing lymphoma cells to various chemotherapeutic drugs. We found low level of curcumin (5 μM) sensitized lymphoma cells to anti-tumoral DNA damage agents including cisplatin, methyl methanesulfonate, hydroxyurea and camptothecin. We also found curcumin sensitized CH12F3 lymphoma cells to DNA-PK and PARP inhibitors. Flow cytometry analysis showed curcumin promoted apoptosis and western blot analysis confirmed curcumin activated caspase3-dependent apoptosis. Taken together, these results demonstrate that curcumin induces DNA damage through regulating Rad51-dependant homologous recombination and triggers caspase3-dependent apoptosis, more importantly, curcumin sensitizes lymphoma cells to various DNA damage drugs. Consequently, curcumin would be a potent agent for sensitizing lymphoma cells to anti-tumoral chemotherapeutic agents. [ABSTRACT FROM AUTHOR]