Rab22a is a novel prognostic marker for cell progression in breast cancer

Linc00239 Facilitates the Progress of Clear Cell Renal Cell Carcinoma via the miR-204-5p/RAB22A Axis

Long intergenic non-coding RNA 239 (Linc00239) acts as an oncogene in colorectal cancer (CRC), esophageal squamous cell carcinoma, and acute myeloid leukemia cells. However, its role and regulatory mechanisms in clear cell renal cell carcinoma (ccRCC) remain unknown. We used StarBase and The Cancer Genome Atlas databases to evaluate Linc00239 expression and its effect on ccRCC. Furthermore, the function of Linc00239 in ccRCC proliferation and metastasis was analyzed using Cell Counting Kit-8 and Transwell assays following Linc00239 knockdown. Subsequently, the Linc00239-miRNA-mRNA regulatory associations were selected based on miRanda, miTarbase, and previous references, and their expression levels and binding relationship were further validated using quantitative real-time polymerase chain reaction, western blotting and dual-luciferase reporter gene assay. Additionally, we transfected a miRNA inhibitor to evaluate whether the miR-204-5p/RAB22A (Ras-related proteins in brain 22a) axis was involved in Linc00239 function. Linc00239 was elevated in ccRCC and correlated with poor prognosis. Linc00239 knockdown inhibited ccRCC progression. Additionally, Linc00239 inhibition elevated miR-204-5p expression and repressed RAB22A levels. Moreover, miR-204-5p inhibitors attenuated this inhibitory effect on proliferation, migration, invasion, and RAB22A level when Linc00239 was knocked down. Linc00239 promotes ccRCC proliferation and metastasis by elevating RAB22A expression through the adsorption of miR-204-5p, which provides a clue for the diagnosis and treatment of ccRCC.

RAB22A as a predictor of exosome secretion in the progression and relapse of multiple myeloma

BACKGROUND

Multiple myeloma (MM) is an incurable malignant plasma cell disease. We explored the role of RAB22A in exosome secretion, epithelial-mesenchymal transition (EMT) and immune regulation.

METHODS

We obtained MM samples from Gene Expression Omnibus (GEO) data sets. We downloaded the "IOBR" package, and used the "PCA" and "ssGSEA" algorithms to calculate the EMT scores and exosome scores. The "CIBERSORT" package was used to analyze the infiltration of immune cells. We extracted the exosomes of mesenchymal stem cell (MSC) to verify the biological function of RAB22A.

RESULTS

The expression level of RAB22A in smoldering multiple myeloma (SMM) and MM patients was significantly higher than that in normal people and monoclonal gammopathy of undetermined significance (MGUS) patients, and the expression level of RAB22A in relapse MM patients was significantly higher than that in newly diagnosed patients. The EMT scores and exosome scores of high RAB22A group were significantly higher than those of low RAB22A group, and the exosome scores of MSC in recurrent patients were significantly higher than those of newly diagnosed patients. In addition, the infiltration levels of monocyte, NK cells resting, eosinophils, T cells regulatory and T cells CD4 memory activated were positively correlated with RAB22A. After down-regulating the expression of RAB22A in MM-MSC, the secretion of exosomes decreased. Compared with the exosomes of MSC in si-RAB22A group, the exosomes in control group significantly promoted the proliferation of MM.

CONCLUSIONS

RAB22A is a potential therapeutic target to improve the prognosis of MM, which is closely related to exosome secretion, EMT and immune cell infiltration.

Rab22a Promotes Epithelial-Mesenchymal Transition in Papillary Thyroid Carcinoma by Activating PI3K/AKT/mTOR Signaling Pathway

Background

Rab22a is a member of the RAS superfamily, involved in early endosome formation and intracellular vesicle transport. Rab22a is significantly upregulated in a variety of malignant tumors. However, its function in thyroid cancer has never been addressed.

Methods

The expression of Rab22a in paraffin sections of 101 patients was detected by immunohistochemical staining. By upregulating and downregulating the expression of Rab22a in thyroid cancer cell lines, the effect of Rab22a on cell proliferation, invasion, and migration was analyzed. Co-IP was employed, and the interaction between Rab22a and PI3Kp85α was shown. The function of Rab22a on PI3K/AKT/mTOR signaling and epithelial-mesenchymal transition (EMT) was further studied by western blot analysis.

Results

Immunostaining showed that Rab22a was significantly overexpressed in thyroid cancer tissues but negative in adjacent normal tissues or nodular goiters. The proliferation, migration, invasion, and EMT in papillary thyroid carcinoma cell lines were enhanced upon Rab22a overexpression but inhibited after knocking down Rab22a. The co-IP assay demonstrated an interaction between Rab22a and PI3K85α, an effector of PI3K. We further found that Rab22a can activate the PI3K/AKT/mTOR signaling pathway. However, the ability of Rab22a to promote the proliferation, invasion, migration, and EMT of papillary thyroid carcinoma cells was significantly inhibited after being treated with LY294002, a PI3K inhibitor.

Conclusions

Rab22a can promote the EMT process and enhance proliferation, migration, and invasion of papillary thyroid carcinoma cells by activating the PI3K/AKT/mTOR signaling pathway. Our study provides new pathological diagnosis clues and clinical treatment targets for thyroid cancer.

CircNRIP1 Exerts Oncogenic Functions in Papillary Thyroid Carcinoma by Sponging miR-653-5p and Regulating PBX3 Expression

Background

Circular RNA circ_0004771 (termed circNRIP1) was identified by RNA-Seq previously and was elevated in papillary thyroid carcinoma (PTC) tissues. A series of studies also showed that circNRIP1 was upregulated in some tumors and could promote the malignant progression of tumors. This research intended to focus on the role of circNRIP1 in PTC progression and explore the mechanisms underlying circNRIP1 functions.

Methods

RT-PCR or western blot determined circNRIP1, miR-653-5p, and pre-B-cell leukemia homeobox 3 (PBX3) expression. EdU, CCK-8, Tunel, and transwell assays determined cell proliferation, apoptosis, invasion, and migration, respectively. Luciferase reporter assay, RNA immunoprecipitation (RIP), and RNA pull down assays clarified the target relation between miR-653-5p and circNRIP1 or PBX3. Xenograft models were applied to explore the role of circNRIP1 in vivo.

Results

circNRIP1 significantly increased in PTC tissues and PTC cell lines than that in normal ones. Higher circNRIP1 expression was associated with the TNM stage and poorer overall survival. circNRIP1 knockdown attenuated the malignant progression of PTC, specifically by inhibiting proliferation and invasion/migration and promoting apoptosis. circNRIP1 was a miR-653-5p sponge; miR-653-5p knockdown reversed the suppressive role of circNRIP1 silence in PTC progression. PBX3, a target of miR-653-5p, was positively medicated through circNRIP1 via competitively sponging miR-653-5p. Knockdown of circNRIP1 attenuated the PTC tumor progression via miR-653-5p/PBX3 axis.

Conclusion

Silencing of circNRIP1 suppressed PTC development via miR-653-5p elevation and PBX3 reduction, providing a novel perspective for understanding PTC pathogenesis.

Comprehensive Analysis of Expression, Clinicopathological Association and Potential Prognostic Significance of RABs in Pancreatic Cancer

RAB proteins (RABs) represent the largest subfamily of Ras-like small GTPases that regulate a wide variety of endosomal membrane transport pathways. Their aberrant expression has been demonstrated in various malignancies and implicated in pathogenesis. Using The Cancer Genome Atlas (TCGA) database, we analyzed the differential expression and clinicopathological association of RAB genes in pancreatic ductal adenocarcinoma (PDAC). Of the 62 RAB genes analyzed, five (RAB3A, RAB26, RAB25, RAB21, and RAB22A) exhibited statistically significant upregulation, while five (RAB6B, RAB8B, RABL2A, RABL2B, and RAB32) were downregulated in PDAC as compared to the normal pancreas. Racially disparate expression was also reported for RAB3A, RAB25, and RAB26. However, no clear trend of altered expression was observed with increasing stage and grade, age, and gender of the patients. PDAC from occasional drinkers had significantly higher expression of RAB21 compared to daily or weekly drinkers, whereas RAB25 expression was significantly higher in social drinkers, compared to occasional ones. The expression of RABL2A was significantly reduced in PDAC from diabetic patients, whereas RAB26 was significantly lower in pancreatitis patients. More importantly, a significant association of high expression of RAB21, RAB22A, and RAB25, and low expression of RAB6B, RABL2A, and RABL2B was observed with poorer survival of PC patients. Together, our study suggests potential diagnostic and prognostic significance of RABs in PDAC, warranting further investigations to define their functional and mechanistic significance.