A thorough analysis of data on the correlation between COL9A1 polymorphisms and the susceptibility to congenital talipes equinovarus: a meta-analysis.

BACKGROUND: Congenital talipes equinovarus (CTEV) is a prevalent pediatric deformity with a multifactorial etiology. The objective of this meta-analysis was to explore the association between genetic variations in COL9A1 and the susceptibility to CTEV. METHODS: A comprehensive analysis of pertinent literature released before November 15, 2023, in electronic bibliographic databases was carried out. The importance of the connection was clarified through odds ratios (ORs) with 95% confidence intervals (CIs), utilizing random or fixed-effects models depending on study heterogeneity. Statistical analysis was executed using Comprehensive Meta-Analysis software (Version 4.0). RESULTS: A total of eight case-control studies involving 833 CTEV patients and 1280 healthy individuals were included in the analysis. Among these, four studies investigated the rs1135056 variant, encompassing 432 CTEV cases and 603 controls; two studies examined the rs35470562 variant, with 189 CTEV cases and 378 controls; and two studies explored the rs592121 variant, including 212 CTEV cases and 299 controls. The results revealed a significant association between the rs1135056 and rs35470562 polymorphisms in the COL9A1 gene, suggesting an increased risk of CTEV in the overall population. Conversely, no such association was found for the rs592121 variant. CONCLUSION: Our findings reveal a substantial association between the genetic variants COL9A1 rs1135056 and rs35470562 and susceptibility to CTEV. Conversely, the variant rs592121 did not exhibit any corresponding link. However, the limitations imposed by the small study population have compromised the statistical reliability and generalizability of the results.

A novel missense COL9A3 variant in a pedigree with multiple lumbar disc herniation.

Trp3 allele in COL9A3 gene has been widely studied in populations with intervertebral disc disease. We identified a novel pathogenic variant in COL9A3 gene in a pedigree with multiple lumbar disc herniation (LDH). The proband was a 14-year-old boy who developed LDH at the L4/5 and L5/S1 spinal segments. His father, paternal aunt and grandfather were diagnosed with LDH at an age of 35, 30 and 23, respectively. By applying whole exome sequencing, a heterozygous missense variant (c.1150C > T, p.Arg384Trp) in COL9A3 was identified. According to the ACMG guidelines, this variant is predicted to be pathogenic. In addition, prediction tools found COL9A3 protein of this variant a reduced stability, some changed charge properties, and an altered spatial conformation. Findings expanded the mutational spectrum of LDH and contributed to the understanding of COL9A3 in the pathogenesis of LDH.

Hearing Loss in Stickler Syndrome: An Update.

Stickler syndrome is a connective tissue disorder characterized by ocular, skeletal, orofacial and auditory manifestations. Its main symptoms are high myopia, retinal detachment, joint hypermobility, early osteoarthritis, cleft palate, midfacial hypoplasia, micrognathia and hearing loss. Large phenotypical variability is apparent and partly explained by the underlying genetic heterogeneity, including collagen genes (COL2A1, COL11A1, COL11A2, COL9A1, COL9A2, COL9A3) and non-collagen genes (BMP4, LRP2, LOXL3). The most frequent type of Stickler syndrome (COL2A1) is characterized by a rather mild high-frequency sensorineural hearing loss in about half of the patients. COL11A1- and COL11A2-related Stickler syndrome results in more frequent hearing loss, being moderate and involving all frequencies. Hearing loss in the rarer types of Stickler syndrome depends on the gene expression in the cochlea, with moderate to severe downsloping hearing loss for Stickler syndrome caused by biallelic type IX collagen gene mutations and none or mild hearing loss for the non-collagen genes. Inherent to the orofacial manifestations, middle ear problems and temporary conductive hearing loss, especially at young age, are also prevalent. Consequently, hearing loss should be actively sought for and adequately treated in Stickler syndrome patients given its high prevalence and the concomitant visual impairment in most patients.

Identification of three novel homozygous variants in COL9A3 causing autosomal recessive Stickler syndrome.

BACKGROUND: Stickler syndrome (STL) is a rare, clinically and molecularly heterogeneous connective tissue disorder. Pathogenic variants occurring in a variety of genes cause STL, mainly inherited in an autosomal dominant fashion. Autosomal recessive STL is ultra-rare with only four families with biallelic COL9A3 variants reported to date. RESULTS: Here, we report three unrelated families clinically diagnosed with STL carrying different novel biallelic loss of function variants in COL9A3. Further, we have collected COL9A3 genotype-phenotype associations from the literature. CONCLUSION: Our report substantially expands the molecular genetics and clinical basis of autosomal recessive STL and provides an overview about allelic COL9A3 disorders.

USP3 promotes gastric cancer progression and metastasis by deubiquitination-dependent COL9A3/COL6A5 stabilisation.

As an important regulator of intracellular protein degradation, the mechanism of the deubiquitinating enzyme family in tumour metastasis has received increasing attention. Our previous study revealed that USP3 promotes tumour progression and is highly expressed in gastric cancer (GC). Herein, we report two critical targets, COL9A3 and COL6A5, downstream of USP3, via the isobaric tags for relative and absolute quantification technique. Mechanistically, we observed that USP3 interacted with and stabilised COL9A3 and COL6A5 via deubiquitination in GC. Importantly, we found that COL9A3 and COL6A5 were essential mediators of USP3-modulated oncogenic activity in vitro and in vivo. Examination of clinical samples confirmed that elevated expression of USP3, concomitant with increased COL9A3 and COL6A5 abundance, correlates with human GC progression. These data suggest that USP3 promotes GC progression and metastasis by deubiquitinating COL9A3 and COL6A5. These findings identify a mechanism of GC metastasis regarding USP3-mediated deubiquitinating enzyme activity and suggest potential therapeutic targets for GC management.

Association between polymorphisms of collagen genes and susceptibility to intervertebral disc degeneration: a meta-analysis.

BACKGROUND: Collagens are important structural components of intervertebral disc. A number of studies have been performed for association between polymorphisms of collagen genes and risk of intervertebral disc degeneration (IVDD) but yielded inconsistent results. Here, we performed a meta-analysis to investigate the association of collagen IX alpha 2 (COL9A2) Trp2, collagen IX alpha 3 (COL9A3) Trp3, collagen I alpha 1 (COL1A1) Sp1 and collagen XI alpha 1 (COL11A1) C4603T polymorphisms with susceptibility to IVDD. METHOD: Eligible studies were retrieved by searching MEDLINE, EMBASE, Web of Science prior to 31 March, 2021. Odds ratio (OR) and corresponding 95% confidence interval (CI) were calculated for association strength. RESULTS: A total of 28 eligible studies (31 datasets comprising 5497 cases and 5335 controls) were included. COL9A2 Trp2 carriers had an increased risk of IVDD than non-carriers in overall population (OR = 1.43, 95% CI 0.99-2.06, P = 0.058), which did not reach statistical significance. However, Trp2 carriers had 2.62-fold (95% CI 1.15-6.01, P = 0.022) risk than non-carriers in Caucasians. COL9A3 Trp3 was not associated with IVDD risk (OR = 1.28, 95% CI 0.81-2.02, P = 0.299). T allele and TT genotype of COL1A1 Sp1 (+ 1245G > T) were correlated with increased risk of IVDD. Significant associations were found between COL11A1 C4603T and IVDD risk under allelic (OR = 1.33, 95% CI 1.20-1.48), dominant (OR = 1.45, 95% CI 1.26-1.67), recessive (OR = 1.55, 95% CI 1.21-1.98) and homozygote model (OR = 1.81, 95% CI 1.40-2.34). CONCLUSIONS: COL1A1 Sp1 and COL11A1 C4603T polymorphism are associated with IVDD risk while the predictive roles of collagen IX gene Trp2/3 need verification in more large-scale studies.

Clinical and genetic characterization of autosomal recessive stickler syndrome caused by novel compound heterozygous mutations in the COL9A3 gene.

BACKGROUND: Stickler syndrome (STL) is a clinically variable and genetically heterogeneous collagenopathy characterized by ophthalmic, auditory, skeletal, and orofacial abnormalities. STL is mainly inherited in an autosomal dominant pattern with mutations in the COL2A1, COL11A1, and COL11A2 genes. Autosomal recessive forms are rare. However, 19 patients have been reported to date, with STL caused by homozygous or compound heterozygous mutations in genes that encode for the three chains of type IX collagen: COL9A1, COL9A2, and COL9A3. METHODS: Genetic analysis was performed using the next-generation sequencing of 166 genes associated with skeletal disorders and sequenced on an Ion Torrent S5 system with a minimum coverage of 100X. The two variants in the COL9A3 gene identified in the proband and the parents were confirmed by Sanger sequencing on an ABI3130xl sequencer. RESULTS: We describe a novel case of autosomal recessive Stickler syndrome caused by two undescribed mutations in the COL9A3 gene: c.268C>T (p.Arg90Ter) and c.1729C>T (p.Arg577Ter). The clinical features included severe sensorineural hearing loss, high myopia, vitreoretinal degeneration, and early-onset arthropathy of the lower limbs. Radiography revealed mild spondyloepiphyseal dysplasia. CONCLUSION: This case further expands the mutational and phenotypic spectrum of COL9A-associated STL with a more severe presentation.

SOX9-COL9A3-dependent regulation of choroid plexus epithelial polarity governs blood-cerebrospinal fluid barrier integrity.

The choroid plexus (CP) is an extensively vascularized neuroepithelial tissue that projects into the brain ventricles. The restriction of transepithelial transport across the CP establishes the blood-cerebrospinal fluid (CSF) barrier that is fundamental to the homeostatic regulation of the central nervous system microenvironment. However, the molecular mechanisms that control this process remain elusive. Here we show that the genetic ablation of Sox9 in the hindbrain CP results in a hyperpermeable blood-CSF barrier that ultimately upsets the CSF electrolyte balance and alters CSF protein composition. Mechanistically, SOX9 is required for the transcriptional up-regulation of Col9a3 in the CP epithelium. The reduction of Col9a3 expression dramatically recapitulates the blood-CSF barrier defects of Sox9 mutants. Loss of collagen IX severely disrupts the structural integrity of the epithelial basement membrane in the CP, leading to progressive loss of extracellular matrix components. Consequently, this perturbs the polarized microtubule dynamics required for correct orientation of apicobasal polarity and thereby impedes tight junction assembly in the CP epithelium. Our findings reveal a pivotal cascade of SOX9-dependent molecular events that is critical for construction of the blood-CSF barrier.

Heterozygous COL9A3 variants cause severe peripheral vitreoretinal degeneration and retinal detachment.

The COL9A3 gene encodes one of the three alpha chains of Type IX collagen, with heterozygous variants reported to cause multiple epiphyseal dysplasia, and suggested as contributory in some cases of sensorineural hearing loss. Patients with homozygous variants have midface hypoplasia, myopia, sensorineural hearing loss, epiphyseal changes and carry a diagnosis of Stickler syndrome. Variants in COL9A3 have not previously been reported to cause vitreoretinal degeneration and/or retinal detachments. This report describes two families with autosomal dominant inheritance and predominant features of peripheral vitreoretinal lattice degeneration and retinal detachment. Genomic sequencing revealed a heterozygous splice variant in COL9A3 [NG_016353.1(NM_001853.4):c.1107 + 1G>C, NC_000020.10(NM_001853.4):c.1107 + 1G>C, LRG1253t1] in Family 1, and a heterozygous missense variant [NG_016353.1(NM_001853.4):c.388G>A p.(Gly130Ser)] in Family 2, each segregating with disease. cDNA studies of the splice variant demonstrated an in-frame deletion in the COL2 domain, and the missense variant occurred in the COL3 domain, both indicating the critical role of Type IX collagen in the vitreous base of the eye.

Gene Environment Interactions Between the COL9A1 Gene and Maternal Drinking of Alcohol Contribute to the Risk of Congenital Talipes Equinovarus.

Background: Previous studies have indicated that both genetic and environmental factors contribute to the risk of congenital talipes equinovarus (CTEV). The COL9A1 gene encodes one of the three alpha chains of type IX collagen, which is a key collagen component of hyaline cartilage. Our study aimed to evaluate the effect of COL9A1 gene polymorphisms on susceptibility to CTEV in the Han Chinese population. Methods: A total of 2205 unrelated subjects comprising 692 CTEV patients and 1513 healthy controls were recruited. Demographic and characteristic information was collected, including maternal smoking and maternal drinking. Genetic association analyses and gene-environment interaction analyses were conducted based on the genotypic data of 36 tag single nucleotide polymorphisms (SNPs). Results: Although there was no association between genotyped SNPs and CTEV, a gene-environment interaction signal between SNP rs6455357 and maternal drinking was identified. Furthermore, significant heterogeneity was identified for this interaction signal when stratified by maternal drinking. For subjects with never maternal drinking, the A allele of SNP rs6455357 was significantly associated with a decreased risk of CTEV. In contrast, the A allele was associated with an increased risk of CTEV in the "occasional" and "often" groups. Conclusions: Our results indicate a combined effect of genetics and environmental factors on the etiology of CTEV. This study increases our understanding of the etiology of CETV and provides useful information for genetic counseling for at-risk families for the development of prevention programs and improved management.

Whole exome sequencing reveals pathogenic variants in MYO3A, MYO15A and COL9A3 and differential frequencies in ancestral alleles in hearing impairment genes among individuals from Cameroon.

There is scarcity of known gene variants of hearing impairment (HI) in African populations. This knowledge deficit is ultimately affecting the development of genetic diagnoses. We used whole exome sequencing to investigate gene variants, pathways of interactive genes and the fractions of ancestral overderived alleles for 159 HI genes among 18 Cameroonian patients with non-syndromic HI (NSHI) and 129 ethnically matched controls. Pathogenic and likely pathogenic (PLP) variants were found in MYO3A, MYO15A and COL9A3, with a resolution rate of 50% (9/18 patients). The study identified significant genetic differentiation in novel population-specific gene variants at FOXD4L2, DHRS2L6, RPL3L and VTN between HI patients and controls. These gene variants are found in functional/co-expressed interactive networks with other known HI-associated genes and in the same pathways with VTN being a hub protein, that is, focal adhesion pathway and regulation of the actin cytoskeleton (P-values <0.05). The results suggest that these novel population-specific gene variants are possible modifiers of the HI phenotypes. We found a high proportion of ancestral allele versus derived at low HI patients-specific minor allele frequency in the range of 0.0-0.1. The results showed a relatively low pickup rate of PLP variants in known genes in this group of Cameroonian patients with NSHI. In addition, findings may signal an evolutionary enrichment of some variants of HI genes in patients, as the result of polygenic adaptation, and suggest the possibility of multigenic influence on the phenotype of congenital HI, which deserves further investigations.

Multiple variants in collagen genes are associated with the susceptibility to lumbar disc herniation in the Chinese population.

PURPOSE: Lumbar disc herniation (LDH) is an important cause of back pain and sciatica, but its aetiology is not fully understood. Single-nucleotide polymorphisms (SNPs) in specific collagen genes are known to increase the risk of lumbar disc degeneration. We performed a case-control study among the Chinese Han population to investigate whether genetic variations in collagen genes were associated with the risk of LDH or not. METHODS: We genotyped SNPs selected from 1000 Genome Projects using Agena MassARRAY technology. Three hundred and eighty-four LDH cases were compared with 384 controls of similar age, using the odds ratio and 95% confidence interval to calculate the susceptibility in several genetic models. RESULTS: Our results revealed that subjects with the rs6122316-C variant of the COL9A3 gene had a higher likelihood of LDH than subjects with the allele T variant in both the codominant and recessive models. In addition, after gender stratification analysis, we found significant associations between rs16970089 and rs740024 and LDH risk in females. Age stratification analysis illustrated that rs16970089 and rs6122316 were also correlated with LDH risk in people over 50 years. The smoking stratification illustrated that rs2071358 and rs740024 had an increased association with LDH risk in smokers. And after drinking stratification, we also observed the significance between rs740024 and LDH risk. CONCLUSIONS: Variants in genes for COL1A1, COL9A3 and COL2A1 significantly influence the risk of LDH. Large and well-designed studies are needed to confirm and explain these conclusions. These slides can be retrieved under Electronic Supplementary Material.

Clinical, histopathological and genetic characterisation of oculoskeletal dysplasia in the Northern Inuit Dog.

Seven Northern Inuit Dogs (NID) were diagnosed by pedigree analysis with an autosomal recessive inherited oculoskeletal dysplasia (OSD). Short-limbed dwarfism, angular limb deformities and a variable combination of macroglobus, cataracts, lens coloboma, microphakia and vitreopathy were present in all seven dogs, while retinal detachment was diagnosed in five dogs. Autosomal recessive OSD caused by COL9A3 and COL9A2 mutations have previously been identified in the Labrador Retriever (dwarfism with retinal dysplasia 1-drd1) and Samoyed dog (dwarfism with retinal dysplasia 2-drd2) respectively; both of those mutations were excluded in all affected NID. Nine candidate genes were screened in whole genome sequence data; only one variant was identified that was homozygous in two affected NID but absent in controls. This variant was a nonsense single nucleotide polymorphism in COL9A3 predicted to result in a premature termination codon and a truncated protein product. This variant was genotyped in a total of 1,232 dogs. All seven affected NID were homozygous for the variant allele (T/T), while 31/116 OSD-unaffected NID were heterozygous for the variant (C/T) and 85/116 were homozygous for the wildtype allele (C/C); indicating a significant association with OSD (p = 1.41x10-11). A subset of 56 NID unrelated at the parent level were analysed to determine an allele frequency of 0.08, estimating carrier and affected rates to be 15% and 0.6% respectively in NID. All 1,109 non-NID were C/C, suggesting the variant is rare or absent in other breeds. Expression of retinal mRNA was similar between an OSD-affected NID and OSD-unaffected non-NID. In conclusion, a nonsense variant in COL9A3 is strongly associated with OSD in NID, and appears to be widespread in this breed.

Exome-wide copy number variation analysis identifies a COL9A1 in frame deletion that is associated with hearing loss.

Pathogenic variants in COL9A1 are primarily associated with autosomal recessive Stickler syndrome. Patients with COL9A1-associated Stickler syndrome (STL) present hearing loss (HL), ophthalmic manifestations and skeletal abnormalities. However, the clinical spectrum of patients with COL9A1 variants can also include multiple epiphyseal dysplasia, as well as non-syndromic HL that was observed in one previously reported proband. Exome sequencing was performed on the genomic DNA of an Iranian patient and his affected brother who both report non-syndromic HL. A 44.6 kb homozygous in-frame deletion spanning exons 6 to 33 of COL9A1 was detected via exome-based copy number variation analysis. The deleted exons were confirmed by PCR in the patient and his affected brother, who both have non-syndromic HL. Segregation analysis via qPCR confirmed the parents as heterozygous deletion carriers. Breakpoint analysis mapped the homozygous deletion spanning introns 5 to 33 (g.70,948,188_70,997,277del, NM_001851.4(COL9A1):c.697-3754_2112+769del, p.(Phe233_Ser704del), with an additional 67 bp of inserted intronic sequence that may have originated due to a fork stalling and template switching/microhomology-mediated break-induced replication (FoSTeS/MMBIR) mechanism. This mechanism has not been previously implicated in HL or STL. This is also the first reported copy number variation in COL9A1 that was identified through an exome data set in an Iranian family with apparent non-syndromic HL. The present study emphasizes the importance of exome-wide copy number variation analysis in molecular diagnosis and provides supporting evidence to associate COL9A1 with autosomal recessive non-syndromic HL.

Variants in FAT1 and COL9A1 genes in male population with or without substance use to assess the risk factors for oral malignancy.

A number of genetic variants were suggested to be associated with oral malignancy, few variants can be replicated. The aim of this study was to identify significant variants that enhanced personal risk prediction for oral malignancy. A total of 360 patients diagnosed with oral squamous cell carcinoma, 486 controls and 17 newly diagnosed patients with OPMD including leukoplakia or oral submucous fibrosis were recruited. Fifteen tagSNPs which were derived from somatic mutations were genotyped and examined in associations with the occurrence of oral malignancy. Environmental variables along with the SNPs data were used to developed risk predictive models for oral malignancy occurrence. The stepwise model analysis was conducted to fit the best model in an economically efficient way. Two tagSNPs, rs28647489 in FAT1 gene and rs550675 in COL9A1 gene, were significantly associated with the risk of oral malignancy. The sensitivity and specificity were 85.7% and 85.5%, respectively (area under the receiver operating characteristic curve (AUC) was 0.91) for predicting oral squamous cell carcinoma occurrence with the combined genetic variants, betel-quid, alcohol and age. The AUC for OPMD was only 0.69. The predictive probability of squamous cell carcinoma occurrence for genetic risk score without substance use increased from 10% up to 43%; with substance use increased from 73% up to 92%. Genetic variants with or without substance use may enhance risk prediction for oral malignancy occurrence in male population. The prediction model may be useful as a clinical index for oral malignancy occurrence and its risk assessments.

Whole-genome sequencing reveals novel genes in ossification of the posterior longitudinal ligament of the thoracic spine in the Chinese population.

BACKGROUND: Ossification of the posterior longitudinal ligament (OPLL) of the spine is a complex, multifactorial disease. Although several genes that are linked to cervical OPLL susceptibility have been reported, specific genetic studies regarding thoracic OPLL are lacking. Whole-genome sequencing has been considered as an efficient strategy to search for disease-causing genes. METHODS: We analysed whole-genome sequences in a cohort of 25 unrelated patients with thoracic OPLL. Bioinformatics analysis and various algorithms were used to predict deleterious variants. Sanger sequencing was used to confirm the variants. RESULTS: Four deleterious mutations in three genes (c.2716C>T (p.Arg906Cys) in collagen type VI α6 (COL6A6); c.1946G>C (p.Gly649Ala) in collagen type IX α1 (COL9A1); and c.301T>C (p.Ser101Pro) and c.171A>G (p.Ile57Met) in toll-like receptor 1 (TLR1)) were successfully identified. All the variants were confirmed by Sanger sequencing. CONCLUSION: The novel deleterious mutations of the three genes may contribute to the development of thoracic OPLL.

Collagen IX gene polymorphisms and lumbar disc degeneration: a systematic review and meta-analysis.

BACKGROUND: An increasing number of studies have investigated associations between collagen IX alpha 2 chain (COL9A2) and collagen IX alpha 3 chain (COL9A3) gene polymorphisms and the risk of lumbar disc degeneration (LDD). However, these studies have yielded contradictory results. The purpose of this meta-analysis is to investigate the association between the collagen IX gene polymorphisms (rs12077871, rs12722877, rs7533552 in COL9A2; rs61734651 in COL9A3) and LDD. METHODS: All relevant articles were collected from PubMed, Web of Science, and China National Knowledge Infrastructure (CNKI). The last electronic search was performed on September 1, 2017. The allele/genotype frequencies were extracted from each study. The odds ratio (OR) and 95% confidence interval (CI) were used to assess the strength of associations under the five comparison genetic models. Statistical analysis was performed by Review Manager (RevMan) 5.31 software. RESULTS: The meta-analysis of 10 case-control studies, including 2102 LDD cases and 2507 controls, indicated that COL9A2 gene (rs12077871, rs12722877, rs7533552) and COL9A3 gene (rs61734651) polymorphisms were not associated with LDD (rs12077871: T vs. C, OR = 1.85, 95% CI = 0.87-3.91, P = 0.11; rs12722877: G vs. C, OR = 0.83, 95% CI = 0.69-1.01, P = 0.06; rs7533552: G vs. A, OR = 1.11, 95% CI = 0.98-1.25, P = 0.09; rs61734651: T vs. C, OR = 1.57, 95% CI = 0.51-4.84, P = 0.43). The Egger text and the Begg funnel plot did not show any evidence of publication bias. CONCLUSION: rs12077871, rs12722877, and rs7533552 variants in COL9A2 and rs61734651 variant in COL9A3 were not significantly associated with a predisposition to LDD. Large-scale and well-designed studies are needed to confirm this conclusion.

ATRA Signaling Regulates the Expression of COL9A1 through BMP2-WNT4-RUNX1 Pathway in Antler Chondrocytes.

Although all-trans retinoic acid (ATRA) is involved in the regulation of cartilage growth and development, its regulatory mechanisms remain unknown. Here, we showed that ATRA could induce the expression of COL9A1 in antler chondrocytes. Silencing of cellular retinoic acid binding protein 2 (CRABP2) could impede the ATRA-induced upregulation of COL9A1, whereas overexpression of CRABP2 presented the opposite effect. RARα agonist Am80 induced the expression of COL9A1, whereas treatment with RARα antagonist Ro 41-5253 or RXRα small-interfering RNA (siRNA) caused an obvious blockage of ATRA on COL9A1. In antler chondrocytes, CYP26A1 and CYP26B1 weakened the sensitivity of ATRA to COL9A1. Simultaneously, Bone morphogenetic protein 2 (BMP2) and WNT4 mediated the regulation of ATRA on COL9A1 expression. Knockdown of WNT4 could abrogate the inhibitory effect of BMP2 overexpression on COL9A1. Conversely, constitutive expression of WNT4 reversed the upregulation of COL9A1 elicited by BMP2 siRNA. Together these data indicated that WNT4 might act downstream of BMP2 to mediate the effect of ATRA on COL9A1 expression. Further analysis evidenced that attenuation of runt-related transcription factor 1 (RUNX1) could prevent the stimulation of ATRA on COL9A1 expression, while exogenous rRUNX1 further enhanced this effectiveness. Moreover, RUNX1 might serve as an intermediate to mediate the regulation of BMP2 and WNT4 on COL9A1 expression. Collectively, ATRA signaling might regulate the expression of COL9A1 through BMP2-WNT4-RUNX1 pathway.

Combined Genetic Biomarkers and Betel Quid Chewing for Identifying High-Risk Group for Oral Cancer Occurrence.

We integrated genetic risk scores (GRS) and environmental factors for identifying high-risk subjects for oral squamous cell carcinoma (OSCC) occurrence by using case-control study. A total of 447 patients diagnosed with OSCC and 580 unrelated subjects were recruited from two medical centers in Taiwan. A multinomial logistic regression model was conducted to access interaction between GRS and betel quid (BQ) chewing. We employed ROC curve to compare the accuracy of OSCC occurrence. Four tag SNPs were found in NOTCH1, BRCA1, COL9A1, and HSPA13 genes that were significantly associated with OSCC occurrence. GRS was calculated by the four tag SNP risk alleles. The higher GRS (scores = 4) remained independently associated with risk of OSCC after adjustment for age, the use of alcohol, BQ, and cigarette: adjusted OR = 4.42 [95% confidence interval (95% CI), 1.34-14.55]. The GRS and BQ chewing interaction showed an increased risk for OSCC occurrence with adjusting for other substance use and age (OR = 70.77; 95% CI, 8.70-575.73). The synergy index was 16.58 (95% CI, 2.27-70.56), suggesting a positive additive interaction between GRS and BQ chewing. The areas under the ROC curves (AUROC) were 0.91 for combined GRS and BQ chewing with sensitivity of 88.6% and specificity of 86.7%. The AUROC of GRS and BQ chewing is above 90%, which may be valuable in identifying high-risk subjects. Early screening can allow the clinician to provide the appropriate intervention and to reduce the OSCC occurrence. Cancer Prev Res; 10(6); 355-62. ©2017 AACR.

Structural insight for chain selection and stagger control in collagen.

Collagen plays a fundamental role in all known metazoans. In collagens three polypeptides form a unique triple-helical structure with a one-residue stagger to fit every third glycine residue in the inner core without disturbing the poly-proline type II helical conformation of each chain. There are homo- and hetero-trimeric types of collagen consisting of one, two or three distinct chains. Thus there must be mechanisms that control composition and stagger during collagen folding. Here, we uncover the structural basis for both chain selection and stagger formation of a collagen molecule. Three distinct chains (α1, α2 and α3) of the non-collagenous domain 2 (NC2) of type IX collagen are assembled to guide triple-helical sequences in the leading, middle and trailing positions. This unique domain opens the door for generating any fragment of collagen in its native composition and stagger.