Inhibition of Atypical Protein Kinase C‑ι Effectively Reduces the Malignancy of Prostate Cancer cells by Downregulating the NF-κB Signaling Cascade

Prostate cancer (PC) is the most common type of cancer among men. Aggressive and metastatic PC results in lifethreatening tumors, and represents one of the leading causes of mortality in men. Previous studies of atypical protein kinase C isoforms (aPKCs) have highlighted its role in the survival of cultured prostate cells via the nuclear factor (NF)-κB pathway. The present study showed that PKC-ι was overexpressed in PC samples collected from cancer patients but not in non-invasive prostate tissues, indicating PKC-ι as a possible prognostic biomarker for the progression of prostate carcinogenesis. Immunohistochemical staining further confirmed the association between PKC-ι and the prostate malignancy. The DU-145 and PC-3 PC cell lines, and the non-neoplastic RWPE-1 prostatic epithelial cell line were cultured and treated with aPKC inhibitors 2-acetyl-1,3-cyclopentanedione (ACPD) and 5-amino-1-(1R,2S,3S,4R)-2,3-dihydroxy-4-methylcyclopentyl)-1H-imidazole-4-carboxamide (ICA-1). Western blot data demonstrated that ICA‑1 was an effective and specific inhibitor of PKC‑ι and that ACPD inhibited PKC-ι and PKC-ζ. Furthermore, the two inhibitors significantly decreased malignant cell proliferation and induced apoptosis. The inhibitors showed no significant cytotoxicity towards the RWPE-1 cells, but exhibited cytostatic effects on the DU-145 and PC-3 cells prior to inducing apoptosis. The inhibition of aPKCs significantly reduced the translocation of NF-κB to the nucleus. Furthermore, this inhibition promoted apoptosis, reduced signaling for cell survival, and reduced the proliferation of PC cells, whereas the normal prostate epithelial cells were relatively unaffected. Overall, the results suggested that PKC-ι and PKC-ζ are essential for the progression of PC, and that ACPD and ICA-1 can be effectively used as potential inhibitors in targeted therapy

Novel molecular, cytotoxical, and immunological study on promising and selective anticancer activity of Mung bean sprouts

<p>Abstract</p> <p>Background</p> <p>The anticancer and immunomodulatory activity of mung bean sprouts (MBS) and the underlying mechanisms against human cervical and hepatocarcinoma cancer cells were explored.</p> <p>Methods</p> <p>MBS cytotoxicity and MBS-induced anticancer cytokines, TNF-α and IFN-β from cancer cells, and immunological cytokines, IL-4, IFN-γ, and IL-10 from peripheral mononuclear cells (PMNC) were assessed by MTS and ELISA assays. Apoptotic cells were investigated by flow cytometry. The expression level of apoptotic genes (Bax, BCL-2, Capsases 7–9) and cell cycle regulatory genes (cyclin D, E, and A) and tumor suppressor proteins (p27, p21, and p53) was assessed by real-time qPCR in the cancer cells treated with extract IC50.</p> <p>Results</p> <p>The cytotoxicity on normal human cells was significantly different from HeLa and HepG2 cells, 163.97 ± 5.73, 13.3 ± 0.89, and 14.04 ± 1.5 mg/ml, respectively. The selectivity index (SI) was 12.44 ± 0.83 for HeLa and 11.94 ± 1.2 for HepG2 cells. Increased levels of TNF-α and IFN-β were observed in the treated HeLa and HepG2 culture supernatants when compared with untreated cells. MBS extract was shown to be an immunopolarizing agent by inducing IFNγ and inhibiting IL-4 production by PBMC; this leads to triggering of CMI and cellular cytotoxicity. The extract induced apoptosis, in a dose and time dependent manner, in treated HeLa and HepG2, but not in untreated, cells (P < 0.05). The treatment significantly induced cell cycle arrest in G0/G1 in HeLa cells. The percentage of cells in G0/G1 phase of the treated HeLa cells increased from 62.87 ± 2.1%, in untreated cells, to 80.48 ± 2.97%. Interestingly, MBS IC50 induced the expression of apoptosis and tumor suppressor related genes in both HeLa and HepG2 cells. MBS extract succeeded in inducing cdk-inhibitors, p21, p53, and p27 in HeLa cells while it induced only p53 in HepG2 cells (P < 0.05). This is a clue for the cell type- specific interaction of the studied extract. These proteins inhibit the cyclin-cdk complexes apart from the presence of some other components that might stimulate some cyclins such as cyclin E, A, and D.</p> <p>Conclusion</p> <p>MBS extract was shown to be a potent anticancer agent granting new prospects of anticancer therapy using natural products.</p