Targeting PELP1 Attenuates Angiogenesis and Enhances Chemotherapy Efficiency in Colorectal Cancer

MicroRNA-299-3p inhibits cell proliferation, motility, invasion and angiogenesis via VEGFA in upper tract urothelial carcinoma

BACKGROUND

Upper tract urothelial carcinoma (UTUC) is a rare tumor with extraordinarily different features between Eastern and Western countries. Vascular endothelial growth factor-A (VEGFA) was originally identified as a secreted signaling protein and regulator of vascular development and cancer progression. In this study, we aimed to elucidate the molecular mechanisms underlying the regulation of VEGFA by microRNA in UTUC.

METHODS

VEGFA expression was evaluated by immunohistochemistry in 140 human UTUC tissue samples. Next, we assessed the regulatory relationship between VEGFA and miR-299-3p by real-time PCR, western blotting, ELISA and dual-luciferase reporter assays using two UTUC cell lines. The role of miR-299-3p/VEGFA in cell proliferation, motility, invasion, and tube formation was analyzed in vitro.

RESULTS

High VEGFA expression was significantly associated with tumor stage, grade, distant metastasis and cancer-related death and correlated with poor progression-free and cancer-specific survival. VEGFA knockdown repressed proliferation, migration, invasion and angiogenesis in UTUC cell lines. miR-299-3p significantly reduced VEGFA protein expression and miR-299-3p overexpression inhibited VEGFA mRNA and protein expression by directly targeting its 3'-UTR. Functional studies indicated that VEGFA overexpression reversed the miR-299-3p-mediated suppression of tumor cell proliferation, migration, invasion and angiogenesis. In addition, miR-299-3p/VEGFA suppressed cellular functions in UTUC by modulating the expression of P18 and cyclin E2.

CONCLUSIONS

Our findings suggest that miR-299-3p possibly suppresses UTUC cell proliferation, motility, invasion and angiogenesis via VEGFA. VEGFA may act as a prognostic predictor, and both VEGFA and miR-299-3p could be potential therapeutic targets for UTUC.

Endostatin induces normalization of blood vessels in colorectal cancer and promotes infiltration of CD8+ T cells to improve anti-PD-L1 immunotherapy

INTRODUCTION

The purpose of this study was to evaluate recombinant human endostatin (rHE)-induced normalization of the tumor vasculature in colorectal cancer (CRC) and to evaluate the therapeutic effects of combined treatment with rHE and a programmed death ligand-1 (PD-L1) inhibitor.

METHODS

A mouse subcutaneous tumorigenesis model was established to evaluate the antitumor effects of endostatin combined with a PD-L1 inhibitor on CRC. Intravoxel incoherent motion diffusion-weighted magnetic resonance imaging (IVIM-DW MRI) was used to evaluate changes in the intratumor microcirculation in response to combined treatment with endostatin and a PD-L1 inhibitor. The infiltration density and function of CD8+ T cells in tumors were evaluated using flow cytometry. Finally, clinical specimens were used to evaluate the expression area of tumor vascular pericytes and CD8+ T cells in tumor tissues.

RESULTS

The antitumor effects of endostatin combined with a PD-L1 inhibitor were significantly greater than those of endostatin or a PD-L1 inhibitor alone. On the ninth day of intervention, the endostatin group showed significantly higher pseudo diffusion parameter (D*) and microvascular volume fraction (F) values in tumors than those in the control group or PD-L1 group. After 27 days of intervention, the endostatin groups showed significantly lower levels of vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-β than those in the control group. Treatment of CD8+ T cells with endostatin for 24 h did not alter the expression levels of markers of reduced T-cell activity. However, endostatin reversed the VEGF-mediated inhibition of the secretion of interferon (IFN)-γ from T cells. The results in CRC clinical samples showed that treatment with endostatin induced significantly higher infiltration of CD8+ T cells compared with treatment that did not include endostatin. Furthermore, the expression area of pericytes was significantly positively related to the infiltration density of CD8+ T cells and overall survival time.

CONCLUSION

Endostatin improved the antitumor effects of PD-L1 inhibitors on CRC, significantly increased the activity of CD8+ T cells, and synergistically improved the tumor treatment effect of the two inhibitors.

METTL3 dual regulation of the stability of LINC00662 and VEGFA RNAs promotes colorectal cancer angiogenesis

PURPOSE

The angiogenesis is among the primary factors that affect tumor recurrence and distant organ metastasis in colorectal cancer (CRC). N6-methyladenosine (m6A) modification is one of the most common chemical modifications in eukaryotic mRNA, especially at the post-transcriptional level. Methyltransferase-like 3 (METTL3) promoting angiogenesis in a variety of tumors has been reported. However, the mechanism of how METTL3 dual-regulates the stability of long non-coding RNAs (lncRNAs) and vascular-related factor RNAs to affect angiogenesis in CRC is unclear.

METHODS

64 paired CRC and adjacent normal tissues were collected. In vitro, quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemistry (IHC), actinomycin assay, methylated RNA immunoprecipitation (MeRIP) experiment,3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) and colony formation assay were performed. The functions were also studied in zebrafish model animals in vivo.

RESULTS

We found that the vascular endothelial growth factor A(VEGFA), METTL3 and LINC00662 RNAs were highly expressed in CRC, and that METTL3 was significantly positively correlated with LINC00662 and VEGFA. The protein expression levels of CD31, CD34, VEGFA, m6A and METTL3 were all significantly increased in the CRC tissues. The angiogenesis experiments both in vivo and in vitro found that METTL3 and LINC00662 promoted angiogenesis in CRC. The actinomycin assay indicated that METTL3 maintained the stability of LINC00662 and VEGFA RNAs. In addition, the MeRIP experiment confirmed that the LINC00662 and VEGFA RNAs had METTL3-enriched sites.

CONCLUSION

These findings suggest that METTL3 and LINC00662 may both serve as diagnostic and prognostic predictive biomarkers for CRC and potential targets for anti-vascular therapy.

Potential of the miR-200 Family as a Target for Developing Anti-Cancer Therapeutics

MicroRNAs (miRNAs) are small non-coding RNAs (18–24 nucleotides) that play significant roles in cell proliferation, development, invasion, cancer development, cancer progression, and anti-cancer drug resistance. miRNAs target multiple genes and play diverse roles. miRNAs can bind to the 3′UTR of target genes and inhibit translation or promote the degradation of target genes. miR-200 family miRNAs mostly act as tumor suppressors and are commonly decreased in cancer. The miR-200 family has been reported as a valuable diagnostic and prognostic marker. This review discusses the clinical value of the miR-200 family, focusing on the role of the miR-200 family in the development of cancer and anti-cancer drug resistance. This review also provides an overview of the factors that regulate the expression of the miR-200 family, targets of miR-200 family miRNAs, and the mechanism of anti-cancer drug resistance regulated by the miR-200 family.