Ginsenoside Rg3 increases gemcitabine sensitivity of pancreatic adenocarcinoma via reducing ZFP91 mediated TSPYL2 destabilization.

Background: Ginsenoside Rg3 and gemcitabine have mutual enhancing antitumor effects. However, the underlying mechanisms are not clear. This study explored the influence of ginsenoside Rg3 on Zinc finger protein 91 homolog (ZFP91) expression in pancreatic adenocarcinoma (PAAD) and their regulatory mechanisms on gemcitabine sensitivity. Methods: RNA-seq and survival data from The Cancer Genome Atlas (TCGA)-PAAD and Genotype-Tissue Expression (GTEx) were used for in-silicon analysis. PANC-1, BxPC-3, and PANC-1 gemcitabine-resistant (PANC-1/GR) cells were used for in vitro analysis. PANC-1 derived tumor xenograft nude mice model was used to assess the influence of ginsenoside Rg3 and ZFP91 on tumor growth in vivo. Results: Ginsenoside Rg3 reduced ZFP91 expression in PAAD cells in a dose-dependent manner. ZFP91 upregulation was associated with significantly shorter survival of patients with PAAD. ZFP91 overexpression induced gemcitabine resistance, which was partly conquered by ginsenoside Rg3 treatment. ZFP91 depletion sensitized PANC-1/GR cells to gemcitabine treatment. ZFP91 interacted with Testis-Specific Y-Encoded-Like Protein 2 (TSPYL2), induced its poly-ubiquitination, and promoted proteasomal degradation. Ginsenoside Rg3 treatment weakened ZFP91-induced TSPYL2 poly-ubiquitination and degradation. Enforced TSPYL2 expression increased gemcitabine sensitivity of PAAD cells and partly reversed induced gemcitabine resistance in PANC-1/GR cells. Conclusion: Ginsenoside Rg3 can increase gemcitabine sensitivity of pancreatic adenocarcinoma at least via reducing ZFP91 mediated TSPYL2 destabilization.

Ginsenoside Rh2 reduces m6A RNA methylation in cancer via the KIF26B-SRF positive feedback loop.

BACKGROUND: The underlying mechanisms of the potential tumor-suppressive effects of ginsenoside Rh2 are complex. N6-methyladenosine (m6A) RNA methylation is usually dysregulated in cancer. This study explored the regulatory effect of ginsenoside Rh2 on m6A RNA methylation in cancer.Methods: m6A RNA quantification and gene-specific m6A RIP-qPCR assays were applied to assess total and gene-specific m6A RNA levels. Co-immunoprecipitation, fractionation western blotting, and immunofluorescence staining were performed to detect protein interactions and distribution. QRT-PCR, dual-luciferase, and ChIP-qPCR assays were conducted to check the transcriptional regulation. RESULTS: Ginsenoside Rh2 reduces m6A RNA methylation and KIF26B expression in a dose-dependent manner in some cancers. KIF26B interacts with ZC3H13 and CBLL1 in the cytoplasm of cancer cells and enhances their nuclear distribution. KIF26B inhibition reduces m6A RNA methylation level in cancer cells. SRF bound to the KIF26B promoter and activated its transcription. SRF mRNA m6A abundance significantly decreased upon KIF26B silencing. SRF knockdown suppressed cancer cell proliferation and growth both in vitro and in vivo, the effect of which was partly rescued by KIF26B overexpression.Conclusion: ginsenoside Rh2 reduces m6A RNA methylation via downregulating KIF26B expression in some cancer cells. KIF26B elevates m6A RNA methylation via enhancing ZC3H13/CBLL1 nuclear localization. KIF26B-SRF forms a positive feedback loop facilitating tumor growth.

Neferine Inhibits 7,12-Dimethylbenz(a)anthracene-Induced Mammary Tumorigenesis by Suppression of Cell Proliferation and Induction of Apoptosis via Modulation of the PI3K/AKT/NF-κB Signaling Pathway.

AIM: To investigate the anticancer mechanism of neferine on DMBA-prompted mammary tumorigenesis in animals. METHODS: Mammary cancer was prompted by the subcutaneous injection of 25 mg DMBA mixed in 1 ml of the vehicle (sunflower oil [0.5 ml] and saline [0.5 ml]). We analyzed the biochemical and molecular expression of cell-proliferation and apoptotic markers in normal and DMBA-induced rats. RESULTS: We detected low body weight, elevated quantities of lipid peroxidation, and low antioxidant enzyme activities in mammary tissues of DMBA-induced animals. We also found an invasive ductal carcinoma in DMBA-induced animals by histopathological assessment. Furthermore, western blotting findings displayed an augmented expression of PI3K, AKT, NF-κB, PCNA, cyclin D1, Ki-67, and Bcl-2, while reducing expression of p53, Bax, caspase-3, and caspase-9 in DMBA-induced cancer-bearing animals. RT-PCR results found upregulation of cyclin D1, PCNA, and Ki-67, and reduced expression of p53 in DMBA-prompted animals. The oral administration of neferine effectually inhibited mammary tumors via improved antioxidants and prevented lipid peroxidation activities when compared with tumor-bearing rats. Furthermore, neferine also modulated PI3K/AKT/NF-κB signaling through inhibiting cell proliferation and induced apoptosis in tumor-bearing rats. CONCLUSION: In our findings, we concluded that neferine has an anti-proliferative and enhancing apoptotic property against DMBA-induced mammary cancer.

The IRENA lncRNA converts chemotherapy-polarized tumor-suppressing macrophages to tumor-promoting phenotypes in breast cancer.

Although chemotherapy can stimulate antitumor immunity by inducing interferon (IFN) response, the functional role of tumor-associated macrophages in this scenario remains unclear. Here, we found that IFN-activated proinflammatory macrophages after neoadjuvant chemotherapy enhanced antitumor immunity but promoted cancer chemoresistance. Mechanistically, IFN induced expression of cytoplasmic long noncoding RNA IFN-responsive nuclear factor-κB activator (IRENA) in macrophages, which triggered nuclear factor-κB signaling via dimerizing protein kinase R and subsequently increased production of protumor inflammatory cytokines. By constructing macrophage-conditional IRENA-knockout mice, we found that targeting IRENA in IFN-activated macrophages abrogated their protumor effects, while retaining their capacity to enhance antitumor immunity. Clinically, IRENA expression in post-chemotherapy macrophages was associated with poor patient survival. These findings indicate that lncRNA can determine the dichotomy of inflammatory cells on cancer progression and antitumor immunity and suggest that targeting IRENA is an effective therapeutic strategy to reversing tumor-promoting inflammation.