Effect of mutation at c.493T>C locus of transcription factor HNF1α gene on its protein level.

Hepatocyte nuclear factor 1α (HNF1α) is a transcription factor that is crucial for the regulation to maintain the function of pancreatic ß-cell, hepatic lipid metabolism, and other processes. Mature-onset diabetes of the young type 3 is a monogenic form of diabetes caused by HNF1α mutations. Although several mutation sites have been reported, the specific mechanisms remain unclear, such hot-spot mutation as the P291fsinsC mutation and the P112L mutation and so on. In preliminary studies, we discovered one MODY3 patient carrying a mutation at the c.493T>C locus of the HNF1α gene. In this study, we analyzed the pathogenic of the mutation sites by using the Mutation Surveyor software and constructed the eukaryotic expression plasmids of the wild-type and mutant type of HNF1α to detect variations in the expression levels and stability of HNF1α protein by using Western blot. The analyses of the Mutation Surveyor software showed that the c.493T>C site mutation may be pathogenic gene and the results of Western blot showed that both the amount and stability of HNF1α protein expressed by the mutation type plasmid were reduced significantly compared to those by the wild type plasmid (P<0.05). This study suggests that the c.493T>C (p.Trp165Arg) mutation dramatically impacts HNF1α expression, which might be responsible for the development of the disease and offers fresh perspectives for the following in-depth exploration of MODY3's molecular pathogenic process.

CMYC-initiated HNF1A-AS1 overexpression maintains the stemness of gastric cancer cells.

Cancer stem cells (CSCs) are believed to be responsible for cancer metastasis and recurrence due to their self-renewal ability and resistance to treatment. However, the mechanisms that regulate the stemness of CSCs remain poorly understood. Recently, evidence has emerged suggesting that long non-coding RNAs (lncRNAs) play a crucial role in regulating cancer cell function in different types of malignancies, including gastric cancer (GC). However, the specific means by which lncRNAs regulate the function of gastric cancer stem cells (GCSCs) are yet to be fully understood. In this study, we investigated a lncRNA known as HNF1A-AS1, which is highly expressed in GCSC s and serves as a critical regulator of GCSC stemness and tumorigenesis. Our experiments, both in vitro and in vivo, demonstrated that HNF1A-AS1 maintained the stemness of GC cells. Further analysis revealed that HNF1A-AS1, transcriptionally activated by CMYC, functioned as a competing endogenous RNA by binding to miR-150-5p to upregulate ß-catenin expression. This in turn facilitated the entry of ß-catenin into the nucleus to activate the Wnt/ß-catenin pathway and promote CMYC expression, thereby forming a positive feedback loop that sustained the stemness of GCSCs. We also found that blocking the Wnt/ß-catenin pathway effectively inhibited the function of HNF1A-AS1, ultimately resulting in the inhibition of GCSC stemness. Taken together, our results demonstrated that HNF1A-AS1 is a regulator of the stemness of GCSCs and could serve as a potential marker for targeted GC therapy.

HNF1A induces glioblastoma by upregulating EPS8 and activating PI3K/AKT signaling pathway.

Despite the exact biological role of HNF1 homolog A (HNF1A) in the regulatory mechanism of glioblastoma (GBM), the molecular mechanism, especially the downstream regulation as a transcription factor, remains to be further elucidated. Immunohistochemistry was used to detect the expression and clinical relevance of HNF1A in GBM patients. CCK8, TUNEL, and subcutaneous tumor formation in nude mice were used to evaluate the effect of HNF1A on GBM in vitro and in vivo. The correction between HNF1A and epidermal growth factor receptor pathway substrate 8 (EPS8) was illustrated by bioinformatics analysis and luciferase assay. Further mechanism was explored that the transcription factor HNF1A regulated the expression of EPS8 and downstream signaling pathways by directly binding to the promoter region of EPS8. Our comprehensive analysis of clinical samples in this study showed that upregulated expression of HNF1A was associated with poor survival in GBM patients. Further, we found that knockdown of HNF1A markedly suppressed the malignant phenotype of GBM cells in vivo and in vitro as well as promoted apoptosis of tumor cells, which was reversed by upregulation of HNF1A. Mechanistically, HNF1A could significantly activate PI3K/AKT signaling pathway by specifically binding to the promoter regions of EPS8. Moreover, overexpression of EPS8 was able to reverse the apoptosis of tumor cells caused by HNF1A knockdown, thereby exacerbating the GBM progression. Correctively, our study has clarified the explicit mechanism by which HNF1A promotes GBM malignancy and provides a new therapeutic target for further clinical application.

The long noncoding RNA HNF1A-AS1 with dual functions in the regulation of cytochrome P450 3A4.

Cytochrome P450 3A4 (CYP3A4) is the most important and abundant drug-metabolizing enzyme in the human liver. Inter-individual differences in the expression and activity of CYP3A4 affect clinical and precision medicine. Increasing evidence indicates that long noncoding RNAs (lncRNAs) play crucial roles in the regulation of CYP3A4 expression. Here, we showed that lncRNA hepatocyte nuclear factor 1 alpha-antisense 1 (HNF1A-AS1) exerted dual functions in regulating CYP3A4 expression in Huh7 and HepG2 cells. Mechanistically, HNF1A-AS1 served as an RNA scaffold to interact with both protein arginine methyltransferase 1 and pregnane X receptor (PXR), thereby facilitating their protein interactions and resulting in the transactivation of PXR and transcriptional alteration of CYP3A4 via histone modifications. Furthermore, HNF1A-AS1 bound to the HNF1A protein, a liver-specific transcription factor, thereby blocking its interaction with the E3 ubiquitin ligase tripartite motif containing 25, ultimately preventing HNF1A ubiquitination and protein degradation, further regulating the expression of CYP3A4. In summary, these results reveal the novel functions of HNF1A-AS1 as the transcriptional and post-translational regulator of CYP3A4; thus, HNF1A-AS1 may serve as a new indicator for establishing or predicting individual differences in CYP3A4 expression.

An Italian MODY family with proband and son carrying variants in GCK and HFN1A: is it a true case of digenic MODY?

Maturity Onset Diabetes of the Young (MODY) is a monogenic autosomal dominant disorder affecting 1-5 % of all patients with diabetes mellitus. In Caucasians, GCK and HNF1A mutations are the most common cause of MODY. Here, we report two family members carrying a genetic variant of both GCK and HNF1A gene and their nine year clinical follow-up. Our report urges physicians to be cautious when variants in two genes are found in a single patient and suggests that collaboration with MODY genetics experts is necessary for correct diagnosis and treatment.

SPOP inhibits HBV transcription and replication by ubiquitination and degradation of HNF1α.

Hepatitis B virus (HBV) infection remains a significant public health burden worldwide. The persistence of covalently closed circular DNA (cccDNA) within the nucleus of infected hepatocytes is responsible for the failure of antiviral treatments. The ubiquitin proteasome system (UPS) has emerged as a promising antiviral target, as it can regulate HBV replication by promoting critical protein degradation in steps of viral life cycle. Speckle-type POZ protein (SPOP) is a critical adaptor for Cul3-RBX1 E3 ubiquitin ligase complex, but the effect of SPOP on HBV replication is less known. Here, we identified SPOP as a novel host antiviral factor against HBV infection. SPOP overexpression significantly inhibited the transcriptional activity of HBV cccDNA without affecting cccDNA level in HBV-infected HepG2-NTCP and primary human hepatocyte cells. Mechanism studies showed that SPOP interacted with hepatocyte nuclear factor 1α (HNF1α), and induced HNF1α degradation through host UPS pathway. Moreover, the antiviral role of SPOP was also confirmed in vivo. Together, our findings reveal that SPOP is a novel host factor which inhibits HBV transcription and replication by ubiquitination and degradation of HNF1α, providing a potential therapeutic strategy for the treatment of HBV infection.

Characterisation of HNF1A variants in paediatric diabetes in Norway using functional and clinical investigations to unmask phenotype and monogenic diabetes.

AIMS/HYPOTHESIS: Correctly diagnosing MODY is important, as individuals with this diagnosis can discontinue insulin injections; however, many people are misdiagnosed. We aimed to develop a robust approach for determining the pathogenicity of variants of uncertain significance in hepatocyte nuclear factor-1 alpha (HNF1A)-MODY and to obtain an accurate estimate of the prevalence of HNF1A-MODY in paediatric cases of diabetes. METHODS: We extended our previous screening of the Norwegian Childhood Diabetes Registry by 830 additional samples and comprehensively genotyped HNF1A variants in autoantibody-negative participants using next-generation sequencing. Carriers of pathogenic variants were treated by local healthcare providers, and participants with novel likely pathogenic variants and variants of uncertain significance were enrolled in an investigator-initiated, non-randomised, open-label pilot study (ClinicalTrials.gov registration no. NCT04239586). To identify variants associated with HNF1A-MODY, we functionally characterised their pathogenicity and assessed the carriers' phenotype and treatment response to sulfonylurea. RESULTS: In total, 615 autoantibody-negative participants among 4712 cases of paediatric diabetes underwent genetic sequencing, revealing 19 with HNF1A variants. We identified nine carriers with novel variants classified as variants of uncertain significance or likely to be pathogenic, while the remaining ten participants carried five pathogenic variants previously reported. Of the nine carriers with novel variants, six responded favourably to sulfonylurea. Functional investigations revealed their variants to be dysfunctional and demonstrated a correlation with the resulting phenotype, providing evidence for reclassifying these variants as pathogenic. CONCLUSIONS/INTERPRETATION: Based on this robust classification, we estimate that the prevalence of HNF1A-MODY is 0.3% in paediatric diabetes. Clinical phenotyping is challenging and functional investigations provide a strong complementary line of evidence. We demonstrate here that combining clinical phenotyping with functional protein studies provides a powerful tool to obtain a precise diagnosis of HNF1A-MODY.

Genetic testing for maturity-onset diabetes of the young resulting in an upgraded genetic classification of an HNF1A gene variant: a case report.

The frequent misdiagnosis of MODY (Maturity-Onset Diabetes of the Young) subtypes makes it necessary to clarify the clinical spectrum of the disease phenotypes in suspected subjects so that accurate diagnosis and management plans can be introduced as early as possible in the course of the disease. We report the case of a MODY subtype that was initially characterized as variant of uncertain significance (VUS) but was later changed to a likely pathogenic variant following our report of two cases where the full expression of the clinical phenotype was described. HNF1A-MODY (Maturity Onset Diabetes of the Young type 3) is one of the most common subtypes of MODY. Due to its variable clinical presentation, and the concerns with being misdiagnosed as either type 1 or type 2 diabetes, DNA sequencing is needed to confirm the diagnosis. This case report illustrates the clinical scenario leading to the identification of the gene variant c.416T>C(p. Leu139Pro) in the HNF1A gene, initially reported as a VUS and later upgraded to a likely pathogenic variant. Though the mutation was described in two Czech family members in 2020, the clinical course and phenotype was not characterized. Therefore, there was the need to fully describe the spectrum of the disease arising from the mutation. The case report fully describes the clinical spectrum of this mutation and provides much needed clinical management approaches to the wider scientific community.

Molecular characterization and re-interpretation of HNF1A variants identified in Indian MODY subjects towards precision medicine.

Background: HNF1A is an essential component of the transcription factor network that controls pancreatic ß-cell differentiation, maintenance, and glucose stimulated insulin secretion (GSIS). A continuum of protein malfunction is caused by variations in the HNF1A gene, from severe loss-of-function (LOF) variants that cause the highly penetrant Maturity Onset Diabetes of the Young (MODY) to milder LOF variants that are far less penetrant but impart a population-wide risk of type 2 diabetes that is up to five times higher. Before classifying and reporting the discovered variations as relevant in clinical diagnosis, a critical review is required. Functional investigations offer substantial support for classifying a variant as pathogenic, or otherwise as advised by the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) ACMG/AMP criteria for variant interpretation. Objective: To determine the molecular basis for the variations in the HNF1A gene found in patients with monogenic diabetes in India. Methods: We performed functional protein analyses such as transactivation, protein expression, DNA binding, nuclear localization, and glucose stimulated insulin secretion (GSIS) assay, along with structural prediction analysis for 14 HNF1A variants found in 20 patients with monogenic diabetes. Results: Of the 14 variants, 4 (28.6%) were interpreted as pathogenic, 6 (42.8%) as likely pathogenic, 3 (21.4%) as variants of uncertain significance, and 1 (7.14%) as benign. Patients harboring the pathogenic/likely pathogenic variants were able to successfully switch from insulin to sulfonylureas (SU) making these variants clinically actionable. Conclusion: Our findings are the first to show the need of using additive scores during molecular characterization for accurate pathogenicity evaluations of HNF1A variants in precision medicine.

Lysine 117 Residue Is Essential for the Function of the Hepatocyte Nuclear Factor 1α.

Hepatocyte nuclear factor 1α (HNF1α) plays essential roles in controlling development and metabolism; its mutations are clearly linked to the occurrence of maturity-onset diabetes of the young (MODY3) in humans. Lysine 117 (K117) to glutamic acid (E117) mutation in the HNF1α gene has been clinically associated with MODY3, but no functional data on this variant are available. Here, we addressed the role of lysine 117 in HNF1α function using a knock-in animal model and site-directed mutagenesis. HNF1α K117E homozygous mice exhibited dwarfism, hepatic dysfunction, renal Fanconi syndrome, and progressive wasting syndrome. These phenotypes were very similar to those of mice with complete HNF1α deficiency, suggesting that K117 is critical to HNF1α functions. K117E homozygotes developed diabetes in the early postnatal period. The relative deficiency of serum insulin levels and the normal response to insulin treatment in homozygous mice were markedly similar to those in the MODY3 disorder in humans. Moreover, K117E heterozygous mutant causes age-dependent glucose intolerance, which is similar to the pathogenesis of MODY3 as well. K117 mutants significantly reduced the overall transactivation and DNA binding capacity of HNF1α by disrupting dimerization. Collectively, our findings reveal a previously unappreciated role of POU domain of HNF1α in homodimerization and provide important clues for identifying the molecular basis of HNF1α-related diseases such as MODY3. ARTICLE HIGHLIGHTS: HNF1α K117E homozygous mice exhibited dwarfism, hepatic dysfunction, renal Fanconi syndrome, and progressive wasting syndrome. K117E homozygotes developed diabetes in the early postnatal period. K117E heterozygous mutant causes age-dependent glucose intolerance, which is similar to the pathogenesis of maturity-onset diabetes of the young. K117 mutants significantly reduced the overall transactivation and DNA binding capacity of HNF1α by disrupting dimerization.

HNF1A binds and regulates the expression of SLC51B to facilitate the uptake of estrone sulfate in human renal proximal tubule epithelial cells.

Renal defects in maturity onset diabetes of the young 3 (MODY3) patients and Hnf1a-/- mice suggest an involvement of HNF1A in kidney development and/or its function. Although numerous studies have leveraged on Hnf1α-/- mice to infer some transcriptional targets and function of HNF1A in mouse kidneys, species-specific differences obviate a straightforward extrapolation of findings to the human kidney. Additionally, genome-wide targets of HNF1A in human kidney cells have yet to be identified. Here, we leveraged on human in vitro kidney cell models to characterize the expression profile of HNF1A during renal differentiation and in adult kidney cells. We found HNF1A to be increasingly expressed during renal differentiation, with peak expression on day 28 in the proximal tubule cells. HNF1A ChIP-Sequencing (ChIP-Seq) performed on human pluripotent stem cell (hPSC)-derived kidney organoids identified its genome-wide putative targets. Together with a qPCR screen, we found HNF1A to activate the expression of SLC51B, CD24, and RNF186 genes. Importantly, HNF1A-depleted human renal proximal tubule epithelial cells (RPTECs) and MODY3 human induced pluripotent stem cell (hiPSC)-derived kidney organoids expressed lower levels of SLC51B. SLC51B-mediated estrone sulfate (E1S) uptake in proximal tubule cells was abrogated in these HNF1A-deficient cells. MODY3 patients also exhibit significantly higher excretion of urinary E1S. Overall, we report that SLC51B is a target of HNF1A responsible for E1S uptake in human proximal tubule cells. As E1S serves as the main storage form of nephroprotective estradiol in the human body, lowered E1S uptake and increased E1S excretion may reduce the availability of nephroprotective estradiol in the kidneys, contributing to the development of renal disease in MODY3 patients.

Insights from basic adjunctive examinations of GCK-MODY, HNF1A-MODY, and type 2 diabetes: A systemic review and meta-analysis.

BACKGROUND: Glucokinase maturity-onset diabetes of the young (GCK-MODY) is difficult to distinguish from other diabetic forms. This article aims to characterize the differences in results from routine examinations between GCK-MODY and hepatocyte nuclear factor 1-α (HNF1A)-MODY or type 2 diabetes (T2D) patients in different periods of diabetes. METHODS: Ovid Medline, Embase, and the Cochrane Library were searched up until October 9, 2022 for articles containing baseline characteristics of GCK-MODY, HNF1A-MOFY, and T2D, excluding pregnant women. The pooled standardized mean differences were derived using a random-effects model. RESULTS: Compared to HNF1A-MODY, GCK-MODY patients had lower indicators of glucose metabolism. Total triglycerides (TG) (-0.93 [-1.66, -0.21] mmol/l) were consistently lower in GCK-MODY patients in the all-family-members subgroup analysis. Compared to T2D, GCK-MODY patients were younger at diagnosis and had lower body mass index (BMI), lower high-sensitivity C-reactive protein (hsCRP) (-0.60 [-0.75, -0.44] mg/l), lower fasting C-peptide (FCP), and lower 2-hour postprandial glucose (2-h PG). Indicators of glycated hemoglobin (HbA1c) and fasting blood glucose (FPG) were consistently lower in subgroup studies with all family members of GCK-MODY patients as well. CONCLUSIONS: Lower HbA1c, FPG, 2-h PG, and change in 2-h PG may help to diagnose GCK-MODY differentially from HNF1A-MODY at an early stage, and lower TG may strengthen such a diagnosis in the follow-up stages. Younger age combined with lower BMI, FCP, hsCRP, and 2-h PG may be useful to distinguish GCK-MODY from MODY-like T2D, whereas results of glucose metabolism indicators such as HbA1c and FPG may not help physicians until after a long follow-up period.

HNF1A regulates oxaliplatin resistance in pancreatic cancer by targeting 53BP1.

DNA double­strand break repair is critically involved in oxaliplatin resistance in pancreatic ductal adenocarcinoma (PDAC). Hepatocyte nuclear factor 1 homeobox A (HNF1A) has received increased attention regarding its role in cancer progression. The present study explored the role of HNF1A in oxaliplatin resistance in PDAC. The results revealed that HNF1A expression was negatively associated with oxaliplatin chemoresistance in PDAC tissues and cell lines. HNF1A inhibition promoted the proliferation, colony formation and stemness of PDAC cells, and suppressed their apoptosis. Furthermore, HNF1A inhibition switched nonhomologous end joining to homologous recombination, thereby enhancing genomic stability and oxaliplatin resistance. Mechanistically, HNF1A transcriptionally activates p53­binding protein 1 (53BP1) expression by directly interacting with the 53BP1 promoter region. Upregulation of HNF1A and 53BP1 induced significant inhibition of PDAC growth and oxaliplatin resistance in patient­derived PDAC xenograft models and orthotopic models. In conclusion, the findings of the present study suggested that HNF1A/53BP1 may be a promising PDAC therapeutic target for overcoming oxaliplatin resistance.

De novo HNF1A mutation of young maturity-onset diabetes 3 of a young girl-Case report.

Young maturity-onset diabetes of the young type3(MODY3) as a special type of diabetes, the probability of diagnosis is low. This article reports on a case and reviews the relevant knowledge of the disease. We report an 11-year-and-11-month-old girl whose grandmother died from diabetic complications while the rest of the families were non-diabetes. The proband was initially treated with insulin and metformin but the threatment proved inefficient. After an exome-targeted capture sequencing test, she was diagnosed with mature-onset diabetes of young type 3 (MODY3), and sulfonylureas make sense. The key to mody treatment is a correct and timely diagnosis, which contributes to helping patients overcome the problems of MODY3, especially for blood sugar control.

Objective and Subjective Sleep Patterns in Adults With Maturity-Onset Diabetes of the Young (MODY).

OBJECTIVE: To examine sleep patterns in adults with maturity-onset diabetes of the young (MODY). RESEARCH DESIGN AND METHODS: Adults with glucokinase (GCK)-MODY and transcription factor (TF)-related MODY (HNF1A, HNF1B, HNF4A) were recruited (n = 24; age 46.0 years, 79% women, BMI 24.7 kg/m2) from The University of Chicago's Monogenic Diabetes Registry. Sleep patterns were assessed by 2-week wrist actigraphy (total 315 nights), one night of a home sleep apnea test, and validated surveys. RESULTS: Overall, compared with established criteria, 29% of participants had sleep latency ≥15 min, 38% had sleep efficiency ≤85%, 46% had wake after sleep onset >40 min, all indicating poor objective sleep quality. Among all participants, 54% had a sleep duration below the recommended minimum of 7 h, 88% reported poor sleep quality, 58% had obstructive sleep apnea, and 71% reported insomnia. Compared with GCK-MODY, participants with TF-related MODY had poorer objective sleep quality and increased night-to-night variability in sleep patterns. CONCLUSIONS: Sleep disturbances appear to be common in adults with MODY despite absent traditional risk factors for sleep disorders. Future research investigating the sleep-diabetes relationship is warranted in this population.

The contribution of functional HNF1A variants and polygenic susceptibility to risk of type 2 diabetes in ancestrally diverse populations.

AIMS/HYPOTHESIS: We examined the contribution of rare HNF1A variants to type 2 diabetes risk and age of diagnosis, and the extent to which their impact is affected by overall genetic susceptibility, across three ancestry groups. METHODS: Using exome sequencing data of 160,615 individuals of the UK Biobank and 18,797 individuals of the BioMe Biobank, we identified 746 carriers of rare functional HNF1A variants (minor allele frequency ≤1%), of which 507 carry variants in the functional domains. We calculated polygenic risk scores (PRSs) based on genome-wide association study summary statistics for type 2 diabetes, and examined the association of HNF1A variants and PRS with risk of type 2 diabetes and age of diagnosis. We also tested whether the PRS affects the association between HNF1A variants and type 2 diabetes risk by including an interaction term. RESULTS: Rare HNF1A variants that are predicted to impair protein function are associated with increased risk of type 2 diabetes in individuals of European ancestry (OR 1.46, p=0.049), particularly when the variants are located in the functional domains (OR 1.89, p=0.002). No association was observed for individuals of African ancestry (OR 1.10, p=0.60) or Hispanic-Latino ancestry (OR 1.00, p=1.00). Rare functional HNF1A variants were associated with an earlier age at diagnosis in the Hispanic-Latino population (ß=-5.0 years, p=0.03), and this association was marginally more pronounced for variants in the functional domains (ß=-5.59 years, p=0.03). No associations were observed for other ancestries (African ancestry ß=-2.7 years, p=0.13; European ancestry ß=-3.5 years, p=0.20). A higher PRS was associated with increased odds of type 2 diabetes in all ancestries (OR 1.61-2.11, p<10-5) and an earlier age at diagnosis in individuals of African ancestry (ß=-1.4 years, p=3.7 × 10-6) and Hispanic-Latino ancestry (ß=-2.4 years, p<2 × 10-16). Furthermore, a higher PRS exacerbated the effect of the functional HNF1A variants on type 2 diabetes in the European ancestry population (pinteraction=0.037). CONCLUSIONS/INTERPRETATION: We show that rare functional HNF1A variants, in particular those located in the functional domains, increase the risk of type 2 diabetes, at least among individuals of European ancestry. Their effect is even more pronounced in individuals with a high polygenic susceptibility. Our analyses highlight the importance of the location of functional variants within a gene and an individual's overall polygenic susceptibility, and emphasise the need for more genetic data in non-European populations.

Concurrent inactivating mutations and expression losses of RGS2, HNF1A, and CAPN12 candidate tumor suppressor genes in colon cancers.

Microsatellite instability-high (MSI-H) colorectal cancer (CRC) is different from microsatellite stable (MSS) CRC concerning biological, and clinical features. In MSI-H CRCs, defects of mismatch repair genes produce increased mutation accumulation in repetitive DNA sequences. To see whether candidate tumor suppressor genes (TSGs) are altered in MSI-H CRC, we studied frameshift mutation and protein expression of candidate TSGs of RGS2, HNF1A, HNF1B, CAPN12, RCBTB2, ATE1, PKNOX1, and USP19. We found frameshift mutations of RGS2 in 5 (5%), HNF1A in 6 (6%), HNF1B in 2 (2%), CAPN12 in 3 (3%), RCBTB2 in 4 (4%), ATE1 in 2 (2%), PKNOX1 in 2 (2%), and USP19 in 2 (2%) MSI-H CRCs. However, we found no such mutations in MSS CRCs. RCBTB2, CAPN12, HNF1A, and HNF1B frameshift mutations revealed the regional difference in the same tumors. In addition, we identified loss of RGS2, HNF1A, and CAPN12 protein expression irrespective of MSI phenotype in 13-29% of CRCs. The results indicate that many TSGs harbor concurrent inactivating mutations and protein loss in MSI-H CRCs with intratumoral mutational heterogeneity, and that MSS CRCs are altered by protein losses. These alterations could contribute to CRC development and underlying mechanisms and consequences of the TSG alterations remain to be clarified.

YTHDF3 mediates HNF1α regulation of cervical cancer radio-resistance by promoting RAD51D translation in an m6A-dependent manner.

Radiotherapy, as an important primary treatment, has effectively improved the survival of patients with cervical cancer (CC). Some patients, however, do not benefit optimally from radiotherapy because of radio-resistance. Therefore, identifying radio-resistance biomarkers and unravelling the underlying mechanisms is of critical importance for these patients. In the present study, we found significant upregulation of hepatocyte nuclear factor 1-alpha (HNF1α) expression in radio-resistant cervical cancer tissues and cell lines. Depletion of HNF1α reduced and overexpression of HNF1α promoted the resistance of CC cells to irradiation in vitro and in vivo. HNF1α positively regulated DNA repair protein RAD51 homologue 4 (RAD51D) at the protein level but not at the mRNA level. Mechanistically, upregulation of HNF1α enhanced YTH domain-containing family protein 3 (YTHDF3) transcription, which in turn promoted RAD51D mRNA N6 -methyladenosine (m6A) modification. YTHDF3 mediates HNF1α regulation of cervical cancer radio-resistance by promoting RAD51D translation in an m6A-dependent manner. The HFN1α/YTHDF3/RAD51D regulatory axis was found to play a critical role in conferring radio-resistance of CC cells. In conclusion, dysregulation of the HFN1α/YTHDF3/RAD51D axis may promote the radio-resistance of CC cells. Blocking this pathway may provide therapeutic benefits against CC radio-resistance.