Analysis of carcinogenic signaling networks in endometrial cancer identifies RAB17 as a potential target

Screening for metastasis-related genes in mouse melanoma cells through sequential tail vein injection

Tumor metastasis, responsible for approximately 90% of cancer-associated mortality, remains poorly understood. Here in this study, we employed a melanoma lung metastasis model to screen for metastasis-related genes. By sequential tail vein injection of mouse melanoma B16F10 cells and the subsequently derived cells from lung metastasis into BALB/c mice, we successfully obtained highly metastatic B16F15 cells after five rounds of in vivo screening. RNA-sequencing analysis of B16F15 and B16F10 cells revealed a number of differentially expressed genes, some of these genes have previously been associated with tumor metastasis while others are novel discoveries. The identification of these metastasis-related genes not only improves our understanding of the metastasis mechanisms, but also provides potential diagnostic biomarkers and therapeutic targets for metastatic melanoma.

Single-cell RNA-seq and bulk-seq identify RAB17 as a potential regulator of angiogenesis by human dermal microvascular endothelial cells in diabetic foot ulcers

Background

Angiogenesis is crucial in diabetic wound healing and is often impaired in diabetic foot ulcers (DFUs). Human dermal microvascular endothelial cells (HDMECs) are vital components in dermal angiogenesis; however, their functional and transcriptomic characteristics in DFU patients are not well understood. This study aimed to comprehensively analyse HDMECs from DFU patients and healthy controls and find the potential regulator of angiogenesis in DFUs.

Methods

HDMECs were isolated from skin specimens of DFU patients and healthy controls via magnetic-activated cell sorting. The proliferation, migration and tube-formation abilities of the cells were then compared between the experimental groups. Both bulk RNA sequencing (bulk-seq) and single-cell RNA-seq (scRNA-seq) were used to identify RAB17 as a potential marker of angiogenesis, which was further confirmed via weighted gene co-expression network analysis (WGCNA) and least absolute shrink and selection operator (LASSO) regression. The role of RAB17 in angiogenesis was examined through in vitro and in vivo experiments.

Results

The isolated HDMECs displayed typical markers of endothelial cells. HDMECs isolated from DFU patients showed considerably impaired tube formation, rather than proliferation or migration, compared to those from healthy controls. Gene set enrichment analysis (GSEA), fGSEA, and gene set variation analysis (GSVA) of bulk-seq and scRNA-seq indicated that angiogenesis was downregulated in DFU-HDMECs. LASSO regression identified two genes, RAB17 and CD200, as characteristic of DFU-HDMECs; additionally, the expression of RAB17 was found to be significantly reduced in DFU-HDMECs compared to that in the HDMECs of healthy controls. Overexpression of RAB17 was found to enhance angiogenesis, the expression of hypoxia inducible factor-1α and vascular endothelial growth factor A, and diabetic wound healing, partially through the mitogen-activated protein kinase/extracellular signal-regulated kinase signalling pathway.

Conclusions

Our findings suggest that the impaired angiogenic capacity in DFUs may be related to the dysregulated expression of RAB17 in HDMECs. The identification of RAB17 as a potential molecular target provides a potential avenue for the treatment of impaired angiogenesis in DFUs.

Downregulation of RAB17 have a poor prognosis in kidney renal clear cell carcinoma and its expression correlates with DNA methylation and immune infiltration

BACKGROUND

RAB17 is one of the RAB family members. It has been reported to be closely associated with a variety of tumors and has different roles in various tumors. However, the effect of RAB17 in KIRC remains unclear.

MATERIALS AND METHODS

We analyzed the differential expression of RAB17 in kidney renal clear cell carcinoma (KIRC) tissues and normal tissues using the public databases. The prognostic role of RAB17 in KIRC was analyzed using the Cox regression methods, and a prognostic model was constructed based on the results of the Cox analysis. In addition, further analysis of RAB17 in KIRC was performed in relation to genetic alterations, DNA methylation m6A methylation and immune infiltration. Finally, RAB17 mRNA and protein expression levels were analyzed in tissue samples (KIRC tissues and normal tissues) and cell lines (normal renal tubular cell and KIRC cells), and in vitro functional assays were performed.

RESULTS

RAB17 was low-expressed in KIRC. Downregulation of RAB17 expression is correlated with unfavorable clinicopathological characteristics and a worse prognosis in KIRC. The RAB17 gene alteration in KIRC was primarily characterized by copy number alteration. Six CpG sites of RAB17 DNA methylation levels are higher in KIRC tissues than in normal tissues, and are correlated with RAB17 mRNA expression levels, showing a significant negative correlation. cg01157280 site DNA methylation levels are associated with pathological stage and overall survival, and it may be the only CpG site with independent prognostic significance. Functional mechanism analysis revealed that RAB17 is closely associated with immune infiltration. RAB17 expression was found to be negatively correlated with most immune cell infiltration according to two different methods. Furthermore, most immunomodulators were significantly negatively correlated with RAB17 expression, and significantly positively correlated with RAB17 DNA methylation levels. RAB17 was significantly low expression in KIRC cells and KIRC tissues. In vitro, silencing of RAB17 promoted KIRC cell migration.

CONCLUSION

RAB17 can be used as a potential prognostic biomarker for patients with KIRC and for assessing immunotherapy response.

Knockdown of Circular RNA Hsa_circ_0000714 Can Regulate RAB17 by Sponging miR-370-3p to Reduce Paclitaxel Resistance of Ovarian Cancer Through CDK6/RB Pathway

Purpose

Paclitaxel resistance in ovarian cancer has become an urgent clinical problem. This study investigated the regulatory effects of RAB17 on the non-coding RNA network of the paclitaxel-resistant ovarian cancer cell A2780/PTX.

Methods

Microarray analysis was used to identify differentially expressed genes in paclitaxel-resistant cell A2780/PTX compared to the parent paclitaxel-sensitive cell A2780. Quantitative real-time PCR and Western blot were used to measure the expression of related mRNAs and proteins. The CCK8 assay was used to determine cell survival ratios and drug resistance indices in ovarian cancer cells. The clone forming assay was used to analyze the cell clone proliferation. Flow cytometry was used to analyze the cell cycle. Dual-luciferase reporter gene assays evaluated the relationship between the genes.

Results

RAB17 is highly expressed in A2780/PTX cells. RAB17 knockdown increased the cell sensitivity to paclitaxel, inhibited proliferation, and caused cell cycle arrest in the G1 phase in A2780/PTX. Western blot confirmed that RAB17 influenced cell behavior by activating the CDK6/RB signaling pathway. Bioinformatics analyses identified RAB17 as a new target by the microRNA miR-370-3p, and the latter was predicted to interact with circular RNA hsa_circ_0000714. Hsa_circ_0000714 indeed acted as a miRNA sponge for miR-370-3p allowing its regulation of RAB17 expression. This regulation was accomplished through the CDK6/RB signaling pathway.

Conclusion

Hsa_circ_0000714 acts as a sponge for miR-370-3p, and regulates RAB17 expression through the CDK6/RB signaling pathway, which plays a role in the malignant progression of the paclitaxel-resistant ovarian cancer cell A2780/PTX.