Glucose deprivation promotes apoptotic response to S1 by enhancing autophagy in human cervical cancer cells

Atorvastatin Enhances Inhibitory Effects of Irradiation on Tumor Growth by Reducing MSH2 Expression both in Prostate Cancer Cells and Xenograft Tumor Models

BACKGROUND

Prostate cancer (PCa) is the fourth most common tumor in males.

OBJECTIVE

To investigate effects of atorvastatin (AS) on PCa cells proliferation and clarify the associated mechanisms.

METHODS

PCa cell lines were cultured and treated with irradiation (IR) (4 Gy), AS (6 μg/ml), transfected with Bcl-2 siRNA, and then divided into different groups. Xenograft tumor mouse model was established. Bcl-2 and MSH2 gene transcription and protein expression were evaluated using RT-PCR assay and western blot assay. Plate clone formation assay was employed to examine colony formation. MTT assay was used to detect cell viabilities. Flow cytometry analysis was utilized to verify apoptosis. Co-immunoprecipitation and immuno-fluorescence assay were used to identify interaction between Bcl-2 and MSH2.

RESULTS

IR significantly reduced colony formation, enhanced Bcl-2 and reduced MSH2 gene transcription in PCa cells compared to un-treated cells (p<0.05). AS significantly strengthened radio-therapeutic effects of IR on colony formation, decreased cell apoptosis and increased Bcl-2 gene transcription/protein expression in PCa cells compared to single IR treatment cells (p<0.05). AS combining IR down-regulated MSH2 gene transcription/protein expression in PCa cells compared to single IR treatment cells (p<0.05). Bcl-2 interacted with MSH2 both in PCa cells and tumor tissues administrating with AS. AS enhanced reductive effects of IR on tumor size of Xenograft tumor mice.

CONCLUSION

Atorvastatin administration enhanced inhibitory effects of IR either on PCa cells or on tumor size of Xenograft tumor mice. The inhibitory effects of atorvastatin were mediated by reducing MSH2 expression and triggering interaction between Bcl-2 and MSH2, both in vitro and in vivo levels.

Exosomal release of microRNA-454 by breast cancer cells sustains biological properties of cancer stem cells via the PRRT2/Wnt axis in ovarian cancer

AIMS

Cancer-derived exosomes carrying tumor-derived molecules such as miRNAs and proteins related to various phenotypes have been detected in both the bloodstream and other biofluids of patients with different cancers. Thus, our main purpose here was to determine the role of the exosomal microRNA-454 (miR-454) derived by MDA-MB-231 in self-renewal of cancer stem cells (CSCs) in ovarian cancer (OC).

MATERIALS AND METHODS

Extraction of MDA-MB-231 cells-derived exosomes (231-derived exosomes) was conducted to treat CD44+/CD133+ SKOV3 and CoC1 cells to observe cell growth and stemness. Next, the differentially expressed miRNAs in SKOV3 cells after exosome treatment were filtered using microarray analysis. Subsequently, the cell viability was detected after reducing the exosomal miR-454 and the addition of a Wnt pathway inhibitor C59. Finally, the pro-tumorigenic function of exosomes on OC cells in vivo was investigated.

KEY FINDINGS

After co-culture with 231-derived exosomes, the stemness of CSCs were promoted. Subsequently, the reduction of exosomal miR-454 weakened the roles of exosomes on cell stemness. Proline-rich transmembrane protein 2 (PRRT2) was substantiated as a target gene of miR-454 in SKOV3 and CoC1 cells. C59 reversed the repressive role of exosomes in stemness of CSCs. When being evaluated in a mouse model, exosomal miR-454 led to an efficacious effect in suppressing the tumor weight and volume in vivo.

SIGNIFICANCE

Altogether, 231-derived exosomes carrying miR-454 disrupted the Wnt pathway by targeting PRRT2, thereby promoting CSC stemness in vitro and OC cell growth in vivo.

Sevoflurane attenuates cardiomyocyte apoptosis by mediating the miR-219a/AIM2/TLR4/MyD88 axis in myocardial ischemia/reperfusion injury in mice

Myocardial infarction (MI) is a vital cause of death and disability globally. The primary treatment for diminishing acute myocardial ischemic injury is myocardial reperfusion, which may induce cardiomyocyte death. Our aim is to unravel the mechanism of sevoflurane (Sev) in microRNA-219a (miR-219a)-mediated regulation of absent in melanoma 2 (AIM2) and TLR4/MyD88 pathway during myocardial ischemia/reperfusion (I/R). The area of MI and apoptosis of cardiomyocytes of the developed mouse model were evaluated by TTC staining and TUNEL, respectively. After the determination of miR-219a as our target using microarray analysis, miR-219a atagomiR was used to treat the mouse model. The luciferase assay verified whether miR-219a targeted AIM2, and the miR-219a and AIM2 expression in myocardial tissues was detected by RT-qPCR and Western blot. miR-219a was significantly increased in myocardial tissues from mice treated with Sev, and the area of MI and cardiomyocyte apoptosis were decreased as a consequence. The miR-219a inhibitor reversed the action of Sev. Moreover, overexpression of AIM2 or induction of the TLR4 pathway aggravated myocardial I/R injury alleviated by miR-219a. All in all, the treatment of Sev upregulated miR-219a expression, which blocked the TLR4 pathway by targeting AIM2 and attenuated cardiomyocyte apoptosis in myocardial I/R mouse model.