Background: N‐acetyltransferase 10 ( NAT10 ) is the only enzyme known to mediate the N4‐acetylcytidine (ac4C) modification of mRNA and is crucial for mRNA stability and translation efficiency. However, its role in cancer development and prognosis has not yet been explored. This study aimed to examine the possible role of NAT10 in colon cancer. Methods: The expression levels of NAT10 were evaluated by immunohistochemical analyses with a colon cancer tissue microarray, and its prognostic value in patients was further analyzed. Quantitative real‐time polymerase chain reaction (qRT‐PCR) and Western blotting were performed to analyze NAT10 expression in harvested colon cancer tissues and cell lines. Stable NAT10 ‐knockdown and NAT10 ‐overexpressing colon cancer cell lines were constructed using lentivirus. The biological functions of NAT10 in colon cancer cell lines were analyzed in vitro by Cell Counting Kit‐8 (CCK‐8), wound healing, Transwell, cell cycle, and ferroptosis assays. Xenograft models were used to analyze the effect of NAT10 on the tumorigenesis and metastasis of colon cancer cells in vivo. Dot blotting, acetylated RNA immunoprecipitation‐qPCR, and RNA stability analyses were performed to explore the mechanism by which NAT10 functions in colon cancer progression. Results: NAT10 was upregulated in colon cancer tissues and various colon cancer cell lines. This increased NAT10 expression was associated with shorter patient survival. Knockdown of NAT10 in two colon cancer cell lines (HT‐29 and LoVo) impaired the proliferation, migration, invasion, tumor formation and metastasis of these cells, whereas overexpression of NAT10 promoted these abilities. Further analysis revealed that NAT10 exerted a strong effect on the mRNA stability and expression of ferroptosis suppressor protein 1 ( FSP1 ) in HT‐29 and LoVo cells. In these cells, FSP1 mRNA was found to be modified by ac4C acetylation, and this epigenetic modification was associated with the inhibition of ferroptosis. Conclusions: Our study revealed that NAT10 plays a critical role in colon cancer development by affecting FSP1 mRNA stability and ferroptosis, suggesting that NAT10 could be a novel prognostic and therapeutic target in colon cancer.

It is well known that human clear cell renal cell carcinoma (ccRCC) is a highly immunogenic and chemo-resistant tumor. Recently, emerging data suggest that the immune checkpoint blockade therapy is an important breakthrough in the treatment against ccRCC. HHLA2, a recently reported member of B7 family, is uniquely expressed in humans but not in mice, and it plays an important role in the functional inhibition of CD4 and CD8 T cells. Herein, we aimed to study the clinical implications of HHLA2 expression in human ccRCC and its potential regulatory role in the biological functions of the cancer cells. In the present study, we examined HHLA2 expression in human ccRCC tissues and analyzed the clinical implications as well as prognostic value. The intervention of HHLA2 in human ccRCC cell lines ACHN and 786-O was performed and its effect on the cellular function of the cells was also analyzed. We also identified the differentially expressed genes upon HHLA2 knockdown in ccRCC cell lines by using gene microarray analysis. We found that higher HHLA2 mRNA expression level in human ccRCC tissues compared with that in adjacent normal tissues based on TCGA data, and the HHLA2 expression at mRNA level was positively and significantly correlated with PD-L1, PD-L2, B7-H6, but negatively and significantly correlated with B7-H3. Moreover, our immunohistochemistry study showed that the staining intensity of HHLA2 in human ccRCC tissues was significantly higher than that in the adjacent normal tissues, and the overall survival rate of ccRCC patients with higher HHLA2 expression was significantly poorer than that of the patients with lower HHLA2 expression. Higher expression of HHLA2 in ccRCC tissues was positively and significantly associated with larger tumor size and advanced TNM stage. The COX model revealed that the parameters including patient’s age, TNM stage and HHLA2 expression level could be used as the independent risk factors respectively for the prognostic prediction of the patients. Our cellular study showed that upon knockdown of HHLA2 expression in human ccRCC cell lines, the cell viability, the migration and the invasion ability were significantly inhibited, while the cell cycle arrest at G1 phase was induced and the expressions of Cyclin D1, c-Myc and Cyclin E1 were decreased. In addition, according to the microarray data, the expressions of epithelia-to-mesenchymal transition markers, such as E-cadherin, N-cadherin and Vimentin, were significantly changed after knockdown of HHLA2 expression. Our findings indicated that HHLA2 was involved in the progression of human ccRCC and could be used as an important prognostic predictor for this malignancy.

Background: As an important N6-methyladenosine (m⁶A) regulator, abnormal expression of methyltransferase-like protein 3 (METTL3) has been reported in certain human cancers. Although some data have shown that METTL3 plays an essential role in the progression of clear-cell renal cell carcinoma RCC (ccRCC), the detailed mechanism still remains largely undetermined. Methods: Immunohistochemistry (IHC) assay was used to examine the expression of METTL3 and its clinical implications in human ccRCC by using tissue-microarray (TMA). The cellular models based on ccRCC cell lines such as 786-O and ACHN, were established by operating METTL3 and HHLA2 via knockdown or overexpression, followed by in vitro cellular function studies and in vivo subcutaneous transplantation tumor model. Results: We found that METTL3 expression in ccRCC tissues was significantly higher compared with adjacent normal tissues. We also found the overall survival (OS) of the patients with low METTL3 expression was significantly better compared with the patients with high METTL3 expression. Furthermore, HHLA2^highMETTL3^high could serve as a better prognostic predictor for ccRCC patients. Depletion of METTL3 could significantly inhibit the cell viability, migration, and invasion abilities in ccRCC cell lines. Cellular studies further revealed that METTL3 could regulate HHLA2 expression via m⁶A modification of HHLA2 mRNA. In vitro studies revealed that HHLA2 overexpression could reverse the inhibition of cellular functions mediated by METTL3 depletion. The subcutaneous transplantation tumor model confirmed that HHLA2 overexpression could reverse the inhibition of tumor growth mediated by METTL3 depletion. Conclusion: Our study indicated that METTL3 served as an important prognostic predictor for ccRCC patients, and we demonstrated a novel regulatory mechanism of HHLA2 by mRNA epigenetic modification via METTL3. Moreover, we found that the METTL3/HHLA2 axis could promote tumorigenesis of ccRCC. Collectively, our current findings provided new insights into the therapeutic strategy against this malignancy targeting METTL3.

The swift advancement of single-cell RNA sequencing (scRNA-seq) technology has furnished a crucial instrument for investigating the tumor microenvironment (TME) and its response to immunotherapy. As immunotherapy becomes increasingly prevalent, the challenge of accurately predicting its efficacy has emerged as a prominent focus in contemporary research. In recent years, the utilization of scRNA-seq in the context of immunotherapy has demonstrated promising potential, particularly in the realms of efficacy prediction and biomarker discovery. The heterogeneity of immune cells within the TME exerts intricate and multifaceted influences on treatment response, necessitating comprehensive investigation. Furthermore, the integration of biomaterials into tumor immunotherapy presents novel research opportunities in this domain. scRNA-seq technology offers a systematic approach to evaluating the modifications in the TME induced by biomaterials. This article aims to review the current state of scRNA-seq in the context of immunotherapy, identify existing challenges within related research, and propose future research directions.

The activation of glycolysis, particularly in the context of reprogrammed energy metabolism, is increasingly recognized as a significant characteristic of cancer. However, the precise mechanisms by which glycolysis is promoted in metastatic gastric cancer cells under normal oxygen conditions remain poorly understood. MicroRNAs (miRNAs) play a crucial role in the development of malignant phenotypes in gastric cancer. Nevertheless, our understanding of the specific involvement of miRNAs in hypoxia-induced metabolic shifting and the subsequent metastatic processes is limited. Hypoxia-induced downregulation of miR-598-3p mechanistically leads to the upregulation of RMP and IGF1r, thereby promoting glycolysis. Either overexpression of miR-598-3p or R406 treatment effectively suppresses the metastasis of gastric cancer cells both in vitro and in vivo. Collectively, the depletion of miR-598-3p alters glucose metabolism from oxidative phosphorylation to glycolysis, thereby exacerbating the malignancy of gastric cancer cells. The present findings indicate a potential target for the development of therapeutics against gastric cancers with increased miR-598-3p expression.