In Vitro Effects of Papaverine on Cell Proliferation, Reactive Oxygen Species, and Cell Cycle Progression in Cancer Cells

Papaverine (PPV) is an alkaloid isolated from the Papaver somniferum. Research has shown that PPV inhibits proliferation. However, several questions remain regarding the effects of PPV in tumorigenic cells. In this study, the influence of PPV was investigated on the proliferation (spectrophotometry), morphology (light microscopy), oxidative stress (fluorescent microscopy), and cell cycle progression (flow cytometry) in MDA-MB-231, A549, and DU145 cell lines. Exposure to 150 μM PPV resulted in time- and dose-dependent antiproliferative activity with reduced cell growth to 56%, 53%, and 64% in the MDA-MB-231, A549, and DU145 cell lines, respectively. Light microscopy revealed that PPV exposure increased cellular protrusions in MDA-MB-231 and A549 cells to 34% and 23%. Hydrogen peroxide production increased to 1.04-, 1.02-, and 1.44-fold in PPV-treated MDA-MB-231, A549, and DU145 cells, respectively, compared to cells propagated in growth medium. Furthermore, exposure to PPV resulted in an increase of cells in the sub-G1 phase by 46% and endoreduplication by 10% compared to cells propagated in growth medium that presented with 2.8% cells in the sub-G1 phase and less than 1% in endoreduplication. The results of this study contribute to understanding of effects of PPV on cancer cell lines.

Peperomin E Induces Apoptosis and Cytoprotective Autophagy in Human Prostate Cancer DU145 Cells In Vitro and In Vivo

Peperomin E was first isolated from Peperomia dindygulensis, an anticarcinogenic herb, and exhibited anticancer activity in many cancer cell lines. To date, it is unknown whether peperomin E has an effect on human prostate cancer DU145 cells in vitro and in vivo. In this study, we used MTT to assess the proliferation inhibition activity of peperomin E in DU145 cells in vitro and observed the cell morphological changes by a phase contrast microscope. A DU145 cell xenograft tumor mouse model was used to evaluate the efficacy of peperomin E in vivo. Apoptosis rates were measured by flow cytometry, and protein expression levels were analyzed by western blot. The results showed that peperomin E significantly inhibited the proliferation of DU145 cells in vitro and reduced the weight and volume of tumors in vivo. Peperomin E also significantly induced the apoptosis and autophagic response of DU145 cells. The autophagic inhibitors LY294002 and chloroquine enhanced peperomin E-mediated inhibition of DU145 cell proliferation and induction of DU145 cell apoptosis. The results also showed that the Akt/mTOR pathway participated in peperomin E-induced autophagy in DU145 cells. In summary, our finding showed that peperomin E had an effect on DU145 cells in vitro and in a nude mouse DU145 cell xenograft model in vivo, demonstrated that peperomin E could significantly induce apoptosis and the autophagic response in DU145 cells and that autophagy played a cytoprotective role in peperomin E-treated DU145 cells. These results suggest that the combination of peperomin E treatment and autophagic inhibition has potential for the treatment of prostate cancer.

FAM84B promotes prostate tumorigenesis through a network alteration

Background: The aim of this study was to investigate the contributions of FAM84B in prostate tumorigenesis and progression. Methods: A FAM84B mutant with deletion of its HRASLS domain (ΔHRASLS) was constructed. DU145 prostate cancer (PC) cells stably expressing an empty vector (EV), FAM84B, or FAM84B (ΔHRASLS) were produced. These lines were examined for proliferation, invasion, and growth in soft agar in vitro. DU145 EV and FAM84B cells were investigated for tumor growth and lung metastasis in NOD/SCID mice. The transcriptome of DU145 EV xenografts ( n = 2) and DU145 FAM84B tumors ( n = 2) was determined using RNA sequencing, and analyzed for pathway alterations. The FAM84B-affected network was evaluated for an association with PC recurrence. Results: FAM84B but not FAM84B (ΔHRASLS) increased DU145 cell invasion and growth in soft agar. Co-immunoprecipitation and co-localization analyses revealed an interaction between FAM84B and FAM84B (ΔHRASLS), suggesting an intramolecular association among FAM84B molecules. FAM84B significantly enhanced DU145 cell-derived xenografts and lung metastasis. In comparison with DU145 EV cell-produced tumors, those generated by DU145 FAM84B cells showed a large number of differentially expressed genes (DEGs; n = 4976). A total of 51 pathways were enriched in these DEGs, which function in the Golgi-to-endoplasmic reticulum processes, cell cycle checkpoints, mitochondrial events, and protein translation. A novel 27-gene signature (SigFAM) was derived from these DEGs; SigFAM robustly stratifies PC recurrence in two large PC populations ( n = 490, p = 0; n = 140, p = 4e−11), and remains an independent risk factor of PC recurrence after adjusting for age at diagnosis, Gleason scores, surgical margin, and tumor stages. Conclusions: FAM84B promotes prostate tumorigenesis through a complex network that predicts PC recurrence.

PAQR6 expression enhancement suggests a worse prognosis in prostate cancer patients

ObjectiveThis study aimed to evaluate the expression of progestin and adipoQ receptor family member VI (PAQR6, mPRδ) in prostate cancer and to explore its role in prostate cancer progression.MethodsPAQR6 mRNA expression was evaluated based on the data obtained from the TCGA database and the GEO database. The prognostic value of PAQR6 was explored by Kaplan-Meier analysis. To investigate the role of PAQR6, it was depleted by siRNA in DU145 cells. The effects of depleting PAQR6 on DU145 cell viability and migration were determined by CCK8 assay, colony formation assay, and wound healing assay, respectively. The activation of MEK and ERK were analyzed by western blot.ResultsPAQR6 mRNA expression was significantly up-regulated in prostate cancer tissues and correlated with lower survival rates (p=0.014). Furthermore, qPCR revealed that PAQR6 expression was elevated in DU145 and LNCaP cells compared with RWPE-2 cells. Depleting PAQR6 obviously suppressed DU145 cell proliferation and migration (p<0.01). In addition, the ratio of p-MEK/MEK and p-ERK/ERK was significantly reduced after silencing PAQR6 (p<0.01).ConclusionPAQR6 might play a facilitating role in prostate cancer development by regulating the MAPK signaling pathway. Moreover, it might serve as a potential predictor and therapeutic target in prostate cancer.