Regulation of extracellular and intracellular prolactin on cell proliferation and survival rate through GHR/JAK2/STAT3 pathway in NSCLC

Therapeutic Potential of Exosomal circRNA Derived from Synovial Mesenchymal Cells via Targeting circEDIL3/miR-485-3p/PIAS3/STAT3/VEGF Functional Module in Rheumatoid Arthritis

Background

Synovial inflammation and its associated activation of angiogenesis play critical roles in rheumatoid arthritis (RA). Exosomes, as carriers of genetic information including circular RNAs (circRNAs), have been explored as delivery vehicles for therapeutic molecules. However, the effects of synovial mesenchymal stem cells (SMSCs)-derived exosomal circRNAs and their mechanisms of action in RA progression remain unclear.

Methods

SMSCs-derived exosomes (SMSCs-Exos) were administered to a co-culture of RA fibroblast-like synoviocytes (RA-FLS) and human dermal microvascular endothelial cells (HDMECs) in vitro as well as to a collagen-induced arthritis (CIA) mouse model in vivo. Their effects on VEGF expression and angiogenic activity in vitro and the therapeutic efficacy in vivo were evaluated. Exosomes from circEDIL3-overexpressing SMSCs (Ad-circEDIL3-SMSCs-Exos) were used to further determine the role of circEDIL3 in SMSCs-Exo-based therapy.

Results

Both SMSCs-Exos and Ad-circEDIL3-SMSCs-Exos significantly downregulated the expression of VEGF induced by the IL-6/sIL-6R complex in the supernatants of RA-FLS and HDMECs co-culture as well as in the cell lysate of co-cultured RA-FLS, and the extent of reduction was more pronounced in the latter. Subsequent experiments showed that angiogenic activity was significantly downregulated by SMSCs-Exos and Ad-circEDIL3-SMSCs-Exos due to reduced VEGF expression. CircEDIL3 functioned as a sponge for miR-485-3p, which targeted PIAS3. PIAS3 is known to suppress STAT3 activity and reduce downstream VEGF. Injection of SMSCs-Exos or Ad-circEDIL3-SMSCs-Exos reduced synovial VEGF and consequently ameliorated arthritis severity in the CIA mouse model.

Conclusion

The intracellular transfer of circEDIL3 by SMSCs-Exos may be a potential novel therapeutic strategy for RA.

CircRPPH1 promotes cell proliferation, migration and invasion of non-small cell lung cancer (NSCLC) via the PI3K/AKT and JAK2/STAT3 signaling axes

Non-small cell lung cancer (NSCLC) has markedly increased morbidity and mortality rate worldwide. Circular RNAs (circRNAs) were shown to regulate NSCLC progression. But, the underlying pathways of the circRPPH1-mediated regulation of NSCLC still need further exploration. We evaluated circRPPH1 levels in NSCLC tissues and cell lines via qRT-RCR. Moreover, using ectopic plasmid incorporation and siRNA assays, we analyzed the circRPPH1-mediated regulation of cell proliferation (CP), migration (CM), and invasion (CI) in NSCLC cell lines (H1975 and A549 cells), using CCK-8, colony forming, scratch wound, and transwell assays, respectively. CircRPPH1 levels were remarkably high in the NSCLC tissues and cell lines. The transfection experiments showed that circRPPH1 overexpression was able to promote CP, CM and CI of NSCLC cells, while CP, CM and CI were significantly restrained by the knockdown of circRPPH1. We also displayed that circRPPH1 knockdown suppressed the cell progression via inactivating the PI3K/AKT and JAK2/STAT3 signaling axes. Subsequently, in vivo experiment in nude mice was demonstrated that the inhibition of circRPPH1 could reduce the tumor growth of NSCLC. circRPPH1 may accelerate the growth and metastasis of NSCLC, in culture conditions and in animal models, by stimulating the PI3K/AKT and JAK2/STAT3 signaling axes, thus promoting the development of NSCLC.

The immune microenvironment in EGFR- and ERBB2-mutated lung adenocarcinoma

Background

Targeted therapies have improved survival and quality of life for patients with non-small-cell lung cancer with actionable driver mutations. However, epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 gene (HER2, also known as ERBB2) exon 20 insertions (Ex20mut) are characterized by a poor response to currently approved tyrosine kinase inhibitors and immunotherapies. The underlying immune biology is not well understood.

Materials and methods

We carried out messenger RNA expression profiling of lung adenocarcinomas (ADCs) with ERBB2 (n = 19) and EGFR exon 20-insertion mutations (n = 13) and compared these to tumors with classical EGFR mutations (n = 40, affecting EGFR exons 18, 19 or 21) and EGFR/ERBB2 mutation-negative lung ADC (EGFR/ERBB2wt, n = 26) focusing on immunologically relevant transcripts. Tumor-infiltrating immune cells were estimated from gene expression profiles.

Results

Cytotoxic cells were significantly lower in EGFR-mutated tumors regardless of the affected exon, while Th1 cells were significantly lower in EGFR-Ex20mut compared to EGFR/ERBB2wt tumors. We assessed the differentially expressed genes of ERBB2-Ex20mut and EGFR-Ex20mut tumors compared to EGFR-Ex18/19/21mut and EGFR/ERBB2wt tumors. Of these, the genes GUSB, HDAC11, IFNGR2, PUM1, RASGRF1 and RBL2 were up-regulated, while a lower expression of CBLC, GBP1, GBP2, GBP4 and MYC was observed in all three comparison groups. The omnibus test revealed 185 significantly (FDR = 5%) differentially expressed genes and we found these four most significant gene expression changes in the study cohort: VHL and JAK1 were overexpressed in ERBB2-Ex20mut and EGFR-Ex20mut tumors compared to both EGFR-Ex18/19/21mut and EGFR/ERBB2wt tumors. RIPK1 and STK11IP showed the highest expression in ERBB2-Ex20mut tumors.

Conclusions

Targeted gene expression profiling is a promising tool to read out the characteristics of the tumor microenvironment from routine diagnostic lung cancer biopsies. Significant immune reactivity and specific immunosuppressive characteristics in ERBB2-Ex20mut and EGFR-Ex20mut lung ADC with at least some degree of immune infiltration support further clinical evaluation of immune-modulators as partners of immune checkpoint inhibitors in such tumors.

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Gene expression profiling to characterize the tumor microenvironment is feasible using diagnostic lung cancer biopsies.

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EGFR exon 20-mutated tumors show a higher expression of VHL and an immunologic ‘colder’ phenotype than EGFR/ERBB2wt tumors.

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ERBB2 exon 20-mutated tumors show an overexpression of RIPK1 and STK11IP and a reduction of cytotoxic natural killer cells.

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Drugs targeting these alterations are potential partners of checkpoint blockade in exon 20-mutated non-small-cell lung cancer.

Genistein Directly Represses the Phosphorylation of STAT5 in Lactating Mammary Epithelial Cells

Genistein is a soy isoflavone and shows various physiological activities, such as affinities for estrogen receptors (ERs) and inhibitory effects on the epidermal growth factor receptor (EGFR) pathway. A previous study reported that genistein downregulates milk production ability in mammary epithelial cells (MECs) while decreasing the phosphorylation of STAT5. The ER and EGFR pathways indirectly regulate STAT5. In this study, the repressing mechanism of genistein against the phosphorylation of STAT5 was investigated using a culture model of mouse MECs with milk production ability. The results revealed that genistein did not influence the behavior of ERα and ERβ, whereas genistein immediately repressed the phosphorylation of ERK1/2. However, the decrease in phosphorylated STAT5 occurred independent of the phosphorylation of EGFR. Genistein repressed new phosphorylation of STAT5 by prolactin without influencing the phosphorylation of JAK2. In conclusion, this study indicates that genistein directly inhibits the phosphorylation of STAT5 in lactating MECs.

RET Regulates Human Medullary Thyroid Cancer Cell Proliferation through CDK5 and STAT3 Activation

Medullary thyroid cancer (MTC) is a neuroendocrine tumor that arises from the parafollicular C-cells, which produces the hormone calcitonin. RET is a transmembrane receptor protein-tyrosine kinase, which is highly expressed in MTC. Our previous studies reported that cyclin-dependent kinase 5 (CDK5) plays a crucial role in cancer progression, including MTC. However, the role of CDK5 in GDNF-induced RET signaling in medullary thyroid cancer proliferation remains unknown. Here, we investigated RET activation and its biochemically interaction with CDK5 in GDNF-induced medullary thyroid cancer proliferation. Our results demonstrated that GDNF stimulated RET phosphorylation and thus subsequently resulted in CDK5 activation by its phosphorylation. Activated CDK5 further caused STAT3 activation by its specific phosphorylation at Ser727. Moreover, we also found that GDNF treatment enhanced ERK1/2 and EGR1 activity, which is involved in p35 activation. Interestingly, we identified for the first time that CDK5 physically interacted with RET protein in MTC. Overall, our results provide a new mechanism for medullary thyroid cancer cell proliferation, suggesting that targeting CDK5 may be a promising therapeutic candidate for human medullary thyroid cancer in the near future.

CXCR4 is a prognostic marker that inhibits the invasion and migration of gastric cancer by regulating VEGF expression

Metastasis is the main cause of poor prognosis of patients with gastric cancer (GC). Thus, current research is focused on identifying biomarkers that can predict the prognosis of patients with GC. C-X-C motif chemokine receptor 4 (CXCR4) and vascular endothelial growth factor (VEGF) have been reported to play important roles in different types of malignancies; however, their role in the prognosis of GC remains unknown. The present study aimed to investigate the potential role of CXCR4 and VEGF in predicting the prognosis of patients with GC. Immunohistochemistry analysis was performed to analyze the expression levels of CXCR4 and VEGF in a GC tissue microarray containing GC tissues and adjacent normal tissues. The association between CXCR4 or VEGF expression levels and the clinicopathological characteristics or survival outcomes were assessed. Furthermore, Transwell and wound healing assays were performed to determine the cell invasive and migratory abilities in vitro. The results demonstrated that CXCR4 promoted AGS cell invasion and migration by regulating VEGF expression. In addition, CXCR4 and VEGF expression levels were significantly upregulated in GC tissues compared with adjacent normal tissues, which was associated with a poorer overall survival (OS). Cox regression analysis demonstrated that both upregulated CXCR4 and VEGF expression were independent negative biomarkers of OS. To the best of our knowledge, the present study was the first to discover that CXCR4 and VEGF exert synergistic roles as efficient prognostic indicators for patients with GC.

CircZNF208 enhances the sensitivity to X-rays instead of carbon-ions through the miR-7-5p /SNCA signal axis in non-small-cell lung cancer cells

BACKGROUND

Mounting evidence suggests that circular RNAs (circRNAs) are closely related to the regulation of gene expression during tumour development. However, the role of circRNAs in modulating the radiosensitivity of non-small cell lung cancer (NSCLC) cells has not been explored.

METHODS

Transcriptome sequencing was used to explore the expression profiles of circRNAs in NSCLC. The expression level of circRNAs was changed by inducing instantaneous knockdown or overexpression. Changes in proliferation and radiosensitivity of NSCLC cells were investigated using CCK-8, EDU, and clonal survivals.

RESULTS

By analysing the circRNA expression profile of NSCLC cells, we found that circRNA ZNF208 (circZNF208) was significantly upregulated in a radioresistant NSCLC cell line (A549-R11), which was acquired from the parental NSCLC cell line A549. Knockout experiments indicated that circZNF208 enhanced the radiosensitivity of A549 and A549-R11 cells to X-rays. Mechanistically, circZNF208 upregulated SNCA expression by acting as a sponge of miR-7-5p and subsequently promoted the resistance of NSCLC cells to low linear energy transfer (LET) X-rays. However, this effect was not observed in NSCLC cells exposed to high-LET carbon ions.

CONCLUSIONS

Knockdown of circZNF208 altered the radiosensitivity of patients with NSCLC to X-rays but did not significantly change the sensitivity to carbon ions. Therefore, circZNF208 might serve as a potential biomarker and therapeutic target for NSCLC treatment with radiotherapy of different modalities.