KIAA1429 regulates alternative splicing events of cancer-related genes in hepatocellular carcinoma

Hepatitis B Virus X Protein Contributes to Hepatocellular Carcinoma via Upregulation of KIAA1429 Methyltransferase and mRNA m6A Hypermethylation of HSPG2/Perlecan

Chronic hepatitis B virus (HBV) remains to be the most common risk factor of hepatocellular carcinoma (HCC). While previous work has primarily focussed on understanding the direct and indirect mechanisms of Hepatitis B virus X protein (HBx)-mediated hepatocarcinogenesis, from genetic and epigenetic perspectives, its influence on RNA modification mediated onset of liver malignancies is less well understood. This study explored the role of HBV-encoded HBx in altering the m6A methylome profile and its implications on the pathogenesis of HCC. We established HBx-expressing stable HCC cell lines, Huh7-HBx and HepG2-HBx, and explored the transcriptomic and epitranscriptomic profiles by RNA-seq and MeRIP-seq, respectively. Preliminary results suggest that HBx promotes liver cell proliferation, migration, survival and overall m6A methylation in HCC cells and is involved in modulating the extracellular matrix. We show that HBx mediates liver cell transformation by upregulating KIAA1429 methyltransferase. HBx also drives the expression and hypermethylation of the extracellular matrix protein HSPG2/Perlecan and promotes tumourigenesis. Furthermore, we observed a potential interaction between KIAA1429 and HSPG2 in HCC liver cancer cells and demands further investigation.

CancerHubs: a systematic data mining and elaboration approach for identifying novel cancer-related protein interaction hubs

Conventional approaches to predict protein involvement in cancer often rely on defining either aberrant mutations at the single-gene level or correlating/anti-correlating transcript levels with patient survival. These approaches are typically conducted independently and focus on one protein at a time, overlooking nucleotide substitutions outside of coding regions or mutational co-occurrences in genes within the same interaction network. Here, we present CancerHubs, a method that integrates unbiased mutational data, clinical outcome predictions and interactomics to define novel cancer-related protein hubs. Through this approach, we identified TGOLN2 as a putative novel broad cancer tumour suppressor and EFTUD2 as a putative novel multiple myeloma oncogene.

N6-Methyladenosine Methyltransferase Component KIAA1429 Is a Potential Target of Cancer Therapy

N6-methyladenosine (m6A), the most abundant RNA modification in eukaryotes, has a crucial impact on tumorigenesis. KIAA1429 is the key component of the m6A methyltransferase complex, in which KIAA1429 functions as a scaffold to bridge the catalytic core proteins. KIAA1429 is often overexpressed in malignances, associated with patient prognosis, and required for tumorigenesis. KIAA1429 regulates the expression of a number of tumor-associated genes in an m6A -dependent manner, and thus, contributes to cell proliferation, migration, drug resistance, tumor formation and metastasis. This review focuses on recent progress in the understanding of roles and mechanisms of KIAA1429 in cancers, and offers ideas for potential anti-cancer therapeutic methods by targeting KIAA1429.

Small HBV surface antigen drives regorafenib resistance in HCC via KIAA1429-dependent m6A modification of CCR9

A substantial body of literature, including our own, points to a connection between hepatitis B virus (HBV) infection and the development of drug resistance in hepatocellular carcinoma (HCC), particularly against sorafenib. However, the influence of HBV on resistance to regorafenib, another therapeutic agent, has been less studied. In this study, we used the GEO database (GSE87630) and clinical samples to demonstrate that C-C motif chemokine receptor 9 (CCR9) was highly expressed in HBV-related HCC and predicted poor overall survival. Its overexpression correlated with HBsAg-positive HCC patients. Both univariate and multivariable Cox regression analysis elucidated CCR9 was an independent risk factor for poor overall survival in HCC patients. Our in vitro findings further revealed that HBV structural proteins, small HBV surface antigen (SHBs), triggered an upregulation of CCR9. Functional assays showed that SHBs enhanced HCC cell proliferation, migration, and invasion, increased ABCB1 and ABCC1 expression, and promoted regorafenib resistance via CCR9. Intriguingly, overexpression of HBV plasmid and an AAV-HBV mouse model both exhibited a significant elevation in global N6-methyladenosine (m6A) levels. Further investigations revealed that SHBs elevated these m6A levels, upregulated CCR9 and stabilized CCR9 mRNA through KIAA1429-mediated m6A modification, with sites 1373 and 1496 on CCR9 mRNA being critical for modification. In conclusion, SHBs promoted HCC progression and regorafenib resistance via KIAA1429-mediated m6A modification of CCR9. Our findings suggested that CCR9 could be a potential prognostic biomarker and a valuable molecular therapeutic target of regorafenib resistance in HBV-related HCC.

KIAA1429-mediated RXFP1 attenuates non-small cell lung cancer tumorigenesis via N6-methyladenosine modification

BACKGROUND

N6-methyladenosine (m6A) modification has been associated with non-small cell lung cancer (NSCLC) tumorigenesis.

OBJECTIVES

This study aimed to determine the functions of Vir-like m6A methyltransferase-associated (KIAA1429) and relaxin family peptide receptor 1 (RXFP1) in NSCLC.

METHODS

A quantitative real-time polymerase chain reaction was used to analyze the mRNA levels of KIAA1429 and RXFP1 in NSCLC. After silencing KIAA1429 or RXFP1 in NSCLC cells, changes in the malignant phenotypes of NSCLC cells were assessed using cell counting kit-8, colony formation, and transwell assays. Finally, the m6A modification of RXFP1 mediated by KIAA1429 was confirmed using luciferase, methylated RNA immunoprecipitation, and western blot assays.

RESULTS

KIAA1429 and RXFP1 were upregulated and downregulated in NSCLC, respectively. Silencing of KIAA1429 attenuated the viability, migration, and invasion of NSCLC cells, whereas silencing of RXFP1 showed the opposite function in NSCLC cells. Moreover, RXFP1 expression was inhibited by KIAA1429 via m6A-modification. Therefore, silencing RXFP1 reversed the inhibitory effect of KIAA1429 knockdown in NSCLC cells.

CONCLUSION

Our findings confirmed that the KIAA1429/RXFP1 axis promotes NSCLC tumorigenesis. This is the first study to reveal the inhibitory function of RXFP1 in NSCLC via KIAA1429-mediated m6A-modification. These findings may help identify new biomarkers for targeted NSCLC therapy.

KIAA1429 Promotes Nasopharyngeal Carcinoma Progression by Mediating m6A Modification of PTGS2

Emerging evidence suggests that dysregulation of a N6-methyladenosine (m6A) methyltransferase KIAA1429 participates in the pathogenesis of multiple cancers except for nasopharyngeal carcinoma (NPC). This study is aimed to explore the function of KIAA1429 in NPC progression. The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets were used to confirm the mRNA expression in NPC by bioinformatic analysis. The levels of KIAA1429 and PTGS2 was detected by quantitative reverse transcription polymerase chain reaction and Western blotting. To investigate the effects of KIAA1429/PTGS2 knockdown or overexpression vectors on NPC cell malignancy, cell and animal experiments were performed. Finally, MeRIP and mRNA stability assays were used to verify the m6A modification and mRNA stability, respectively. KIAA1429 was upregulated in NPC tissues and cells. After transfecting KIAA1429 knockdown or overexpression vectors in NPC cells, we proved that KIAA1429 overexpression promoted proliferation, migration, invasion, and tumor growth, whereas KIAA1429 knockdown showed the opposite effect. Our results also indicated that KIAA1429 mediated m6A modification of PTGS2, enhancing PTGS2 mRNA stability in NPC cells. In addition, PTGS2 could also regulate the effects of KIAA1429 on NPC cell malignancy. This study confirmed the oncogenic function of KIAA1429 in NPC through m6A-modification of PTGS2, suggesting that targeting KIAA1429-mediated m6A modification of PTGS2 might provide a new therapeutic strategy for NPC.