FAM83H is involved in stabilization of β-catenin and progression of osteosarcomas

Background

FAM83H was initially identified as a protein essential for dental enamel formation. Recent reports have shown that FAM83H is also involved in the progression of human cancers in conjunction with tumor-associated molecules, such as MYC and β-catenin. However, the role of FAM83H in sarcoma has not yet been investigated.

Methods

The expression and roles of FAM83H and β-catenin were evaluated in human osteosarcomas from 34 patients and osteosarcoma cells.

Results

The expression of nuclear FAM83H, cytoplasmic FAM83H, and β-catenin were significantly associated with each other and significantly associated with shorter survival of osteosarcoma patients by univariate analysis. In multivariate analysis, cytoplasmic expression of FAM83H was an independent indicator of shorter survival of osteosarcoma patients (overall survival; P <  0.001, relapse-free survival; P <  0.001). In U2OS, MG63, and KHOS/NP osteosarcoma cells, the knock-down of FAM83H decreased proliferation and invasion activity and overexpression of FAM83H increased proliferation and invasion activity. In KHOS/NP cells, knock-down of FAM83H significantly inhibited, and overexpression of FAM83H significantly increased in vivo growth of cells. In addition, the knock-down of FAM83H decreased protein expression of β-catenin, active β-catenin, cyclin D1, vimentin, and snail. Overexpression of FAM83H increased protein expression of β-catenin, active β-catenin, cyclin D1, vimentin, and snail. However, the expression of β-catenin mRNA was not significantly altered with knock-down or overexpression of FAM83H. In addition, FAM83H and β-catenin shown to directly interact via immunoprecipitation and nuclear and cytoplasmic localization of β-catenin was decreased with knock-down of FAM83H. Moreover, the ubiquitination and proteasomal degradation of β-catenin was increased with knock-down of FAM83H.

Conclusions

This study suggests that FAM83H is involved in the progression of osteosarcomas via a mechanism involving the stabilization of β-catenin and the promotion of proliferation and invasiveness of osteosarcomas.

MMP20, KLK4, and MMP20/KLK4 double null mice define roles for matrix proteases during dental enamel formation

Matrix metalloproteinase 20 (MMP20) and kallikrein‐related peptidase 4 (KLK4) are secreted proteinases that are essential for proper dental enamel formation. We characterized and compared enamel formed in wild‐type, Mmp20^−/−, Klk4^−/−, Mmp20^+/−Klk4^+/−, and Mmp20^−/−Klk4^−/− mice using dissecting and light microscopy, backscattered scanning electron microscopy (bSEM), SEM, microcomputed tomography (μCT), and energy‐dispersive X‐ray analysis (EDX). Following eruption, fractures were observed on Mmp20^−/−, Klk4^−/−, Mmp20^+/−Klk4^+/−, and Mmp20^−/−Klk4^−/− molars. Failure of the enamel in the Mmp20^+/−Klk4^+/− molars was unexpected and suggested that digenic effects could contribute to the etiology of amelogenesis imperfecta in humans. Micro‐CT analyses of hemimandibles demonstrated significantly reduced high‐density enamel volume in the Mmp20^−/− and Klk4^−/− mice relative to the wild‐type, which was further reduced in Mmp20^−/−Klk4^−/− mice. bSEM images of 7‐week Mmp20^−/− and Mmp20^−/−Klk4^−/− mandibular incisors showed rough, pitted enamel surfaces with numerous indentations and protruding nodules. The Mmp20^+/− and Mmp20^+/−Klk4^+/− incisors showed prominent, evenly spaced, horizontal ridges that were more distinct in Mmp20^+/−Klk4^+/− incisors relative to Mmp20^+/− incisors due to the darkening of the valleys between the ridges. In cross sections, the Mmp20^−/− and Mmp20^−/−Klk4^−/− exhibited three distinct layers. The outer layer exhibited a disturbed elemental composition and an irregular enamel surface covered with nodules. The Mmp20 null enamel was apparently unable to withstand the sheer forces associated with eruption and separated from dentin during development. Cells invaded the cracks and interposed between the dentin and enamel layers. MMP20 and KLK4 serve overlapping and complementary functions to harden enamel by removing protein, but MMP20 potentially serves multiple additional functions necessary for the adherence of enamel to dentin, the release of intercellular protein stores into the enamel matrix, the retreat of ameloblasts to facilitate thickening of the enamel layer, and the timely transition of ameloblasts to maturation.

FAM83H overexpression predicts worse prognosis and correlates with less CD8+ T cells infiltration and Ras-PI3K-Akt-mTOR signaling pathway in pancreatic cancer

BACKGROUND

Family with sequence similarity 83 members H (FAM83H) is one member of Family with sequence similarity 83 (FAM83) family, which possess oncogenic properties in several types of cancer. However, the potential function of FAM83H in pancreatic cancer (PC) still remain unknown.

AIM

This study aims to explore the role of FAM83H during pancreatic carcinogenesis and the regulation of immune infiltration in PC.

METHODS

In the current study, the clinical significance and potential biological of FAM83H were evaluated by bioinformatics analysis. Possible associations between FAM83H expression and tumor immunity were analyzed using ESTIMATE algorithm and single-sample gene set enrichment analysis (ssGSEA).

RESULTS

FAM83H expression was significantly upregulated in tumor tissues, and positively associated with higher histologic grade, tumor recurrence, and worse prognosis. FAM83H overexpression is notably associated with KRAS activation. And functional enrichment analysis demonstrated that FAM83H may be involved in positive regulation of cell proliferation and migration, Ras protein signal transduction, regulation of cell-matrix adhesion, epithelial to mesenchymal transition (EMT), TGF-β receptor signaling in EMT, and activated NOTCH transmits signal to the nucleus. ESTIMATE algorithm and ssGSEA demonstrated that FAM83H overexpression suppressed the infiltration and antitumor activity of tumor-infiltrating lymphocytes (TILs), especially for CD8⁺ T cells. Besides, FAM83H overexpression significantly correlated with low expression of TIL-related gene markers (e.g. CD8A, CD8B, CD2, CD3D, and CD3E).

CONCLUSION

The study suggests that FAM83H overexpression predicts poor prognosis and correlates with less CD8⁺ T cells infiltration and Ras-PI3K-Akt-mTOR signaling pathway in PC.

The Expression Patterns of FAM83H and PANX2 Are Associated With Shorter Survival of Clear Cell Renal Cell Carcinoma Patients

FAM83H is primarily known for its role in amelogenesis; however, recent reports suggest FAM83H might be involved in tumorigenesis. Although the studies of FAM83H in kidney cancer are limited, a search of the public database shows a significant association between FAM83H and pannexin-2 (PANX2) in clear cell renal cell carcinomas (CCRCCs). Therefore, we evaluated the clinicopathological significance of the immunohistochemical expression of FAM83H and PANX2 in 199 CCRCC patients. The expression of FAM83H and PANX2 were significantly associated with each other. In univariate analysis, individual, and co-expression pattern of FAM83H and PANX2 was significantly associated with shorter overall survival (OS) and relapse-free survival (RFS) of CCRCC patients: nuclear expression of FAM83H (OS; P < 0.001, RFS; P < 0.001), cytoplasmic expression of FAM83H (OS; P < 0.001, RFS; P < 0.001), nuclear expression of PANX2 (OS; P < 0.001, RFS; P < 0.001), cytoplasmic expression of PANX2 (OS; P < 0.001, RFS; P < 0.001), co-expression pattern of nuclear FAM83H and nuclear PANX2 (OS; P < 0.001, RFS; P < 0.001). In multivariate analysis, nuclear expression of FAM83H (OS; P < 0.001, RFS; P = 0.003) and the co-expression pattern of nuclear FAM83H and PANX2 (OS; P < 0.001, RFS; P < 0.001) were independent indicators of shorter survival of CCRCC patients. Cytoplasmic expression of FAM83H was associated with shorter RFS (P = 0.030) in multivariate analysis. In Caki-1 and Caki-2 CCRCC cells, knock-down of FAM83H decreased PANX2 expression and cell proliferation, and overexpression of FAM83H increased PANX2 expression and cell proliferation. These results suggest that FAM83H and PANX2 might be involved in the progression of CCRCC in a co-operative manner, and their expression might be used as novel prognostic indicators for CCRCC patients.

FAM83H and SCRIB stabilize β-catenin and stimulate progression of gastric carcinoma

FAM83H primarily is known for its function in tooth development. Recently, a role for FAM83H in tumorigenesis, conjunction with MYC and β-catenin, has been suggested. Analysis of public data indicates that FAM83H expression is closely associated with SCRIB expression in human gastric cancers. Therefore, this study investigated the roles of FAM83H and SCRIB in 200 human gastric cancers and gastric cancer cells. In human gastric carcinomas, both the individual and combined expression patterns of the nuclear FAM83H and SCRIB were independent indicators of shorter survival of gastric carcinoma patients. In MKN-45 and NCI-N87 gastric cancer cells, the expression of FAM83H and SCRIB were associated with proliferation and invasiveness of cells. FAM83H-mediated in vivo tumor growth was attenuated with knock-down of SCRIB. Moreover, immunoprecipitation indicates that FAM83H, SCRIB, and β-catenin, form a complex, and knock-down of either FAM83H or SCRIB accelerated proteasomal degradation of β-catenin. In conclusion, this study has found that the individual and combined expression patterns of nuclear FAM83H and SCRIB are prognostic indicators of gastric carcinomas and further suggests that FAM83H and SCRIB are involved in the progression of gastric carcinomas by stabilizing β-catenin.

TRIM29 in Cutaneous Squamous Cell Carcinoma

Tripartite motif (TRIM) proteins play important roles in a wide range of cell physiological processes, such as signal transduction, transcriptional regulation, innate immunity, and programmed cell death. TRIM29 protein, encoded by the ATDC gene, belongs to the RING-less group of TRIM protein family members. It consists of four zinc finger motifs in a B-box domain and a coiled-coil domain, and makes use of the B-box domain as E3 ubiquitin ligase in place of the RING. TRIM29 was found to be involved in the formation of homodimers and heterodimers in relation to DNA binding; additional studies have also demonstrated its role in carcinogenesis, DNA damage signaling, and the suppression of radiosensitivity. Recently, we reported that TRIM29 interacts with keratins and FAM83H to regulate keratin distribution. Further, in cutaneous SCC, the expression of TRIM29 is silenced by DNA methylation, leading to the loss of TRIM29 and promotion of keratinocyte migration. This paper reviews the role of TRIM family proteins in malignant tumors, especially the role of TRIM29 in cutaneous SCC.

Loss of FAM83H promotes cell migration and invasion in cutaneous squamous cell carcinoma via impaired keratin distribution

BACKGROUNDS

FAM83H is essential for amelogenesis, but recent reports implicate that FAM83H is involved in the tumorigenesis. We previously clarified that TRIM29 binds to FAM83H to regulate keratin distribution and squamous cell migration. However, little is known about FAM83H in normal/malignant skin keratinocytes.

OBJECTIVE

To investigate the expression of FAM83H in cutaneous squamous cell carcinoma (SCC) and its physiological function.

METHODS

Immunohistochemical analysis and RT-PCR of human SCC tissues were performed. Next, we examined the effect of FAM83H knockdown/overexpression in SCC cell lines using cell proliferation, migration, and invasion assay. To investigate the molecular mechanism, immunoprecipitation of FAM83H was examined. Further, Immunofluorescence staining was performed. Finally, we examined the correlation between the expressions of FAM83H and the keratin distribution.

RESULTS

FAM83H expression was lower in SCC lesions than in normal epidermis and correlated with differentiation grade. The mRNA expression levels of FAM83H in SCC tumors were also lower than in normal epidermis. The knockdown of FAM83H enhanced SCC cell migration and invasion, whereas the overexpression of FAM83H led to decreases in both. Furthermore, the knockdown of FAM83H enhanced the cancer cell metastasis in vivo. FAM83H formed a complex with TRIM29 and keratins. The knockdown of FAM83H altered keratin distribution and solubility. Clinically, the loss of FAM83H correlates with an altered keratin distribution.

CONCLUSION

Our findings reveal a critical function for FAM83H in regulating keratin distribution, as well as in the migration/invasion of cutaneous SCC, suggesting that FAM83H could be a crucial molecule in the tumorigenesis of cutaneous SCC.

Family with Sequence Similarity 83 Member H Promotes the Viability and Metastasis of Cervical Cancer Cells and Indicates a Poor Prognosis

PURPOSE

Family with sequence similarity 83 member H (FAM83H) plays key roles in tumorigenesis. However, the specific roles of FAM83H in cervical cancer (CC) have not been well studied.

MATERIALS AND METHODS

The RNA-seq data of 306 CC tissues and three normal samples downloaded from The Cancer Genome Atlas were used to analyze the expression of FAM83H. The Kaplan-Meier method was used to draw survival curves. Associations between FAM83H expression and clinicopathological factors were analyzed by chi-square test. Cox proportional hazards model was used to analyze prognostic factors. Loss-of-function assays were conducted to discover the biological functions of FAM83H in cell proliferation, colony formation, invasion, and migration. Real-time Quantitative Reverse Transcription PCR (qRT-PCR) and Western blotting were used to measure the expression levels of FAM83H in CC cell lines.

RESULTS

Our results demonstrated that FAM83H is overexpressed in CC tissues and that high FAM83H expression is associated with worse overall survival (OS). High FAM83H expression in CC was associated with clinical stage, pathologic tumor, and pathologic node. Univariate analysis suggested that FAM83H expression was significantly related to the OS of CC patients. Although multivariate analysis showed that FAM83H expression was not an independent prognostic factor for the OS of CC patients, the effects of FAM83H on CC cell growth and motility was significant. Loss-of-function experiments demonstrated that knockdown of FAM83H inhibited proliferation, colony formation, migration, and invasion of CC cells by inactivating PI3K/AKT pathway.

CONCLUSION

FAM83H might play a crucial role in CC progression and could act as a novel therapeutic target in CC.

Expression of FAM83H and ZNF16 are associated with shorter survival of patients with gallbladder carcinoma

Background

Recently, FAM83H was reported to have roles in cancer progression in conjunction with oncogenic molecules such as MYC and b-catenin. Moreover, the data from the public database indicates a molecular relationship between FAM83H and zinc finger proteins, especially between FAM83H and ZNF16. However, studies on FAM83H and ZNF16 in gallbladder cancer have been limited.

Methods

This study investigated the expression of FAM83H and ZNF16 in 105 gallbladder carcinomas.

Results

In human gallbladder carcinomas, immunohistochemical expression of FAM83H was significantly associated with ZNF16 expression. In univariate analysis, nuclear and cytoplasmic expression of FAM83H or ZNF16 were significantly associated with shorter survival of gallbladder carcinoma patients. Multivariate analysis revealed the nuclear expression of FAM83H as an independent indicator of poor prognosis of overall survival (p = 0.005) and relapse-free survival (p = 0.005) of gallbladder carcinoma patients. Moreover, co-expression patterns of nuclear FAM83H and ZNF16 were also independent indicators of shorter survival of gallbladder carcinoma patients (overall survival; p <  0.001, relapse-free survival; p <  0.001).

Conclusions

This study suggests FAM83H and ZNF16 are associated with the progression of gallbladder carcinoma, and the expressions of FAM83H and ZNF16 might be novel prognostic indicators of gallbladder carcinoma patients.

The gain-of-function FAM83H mutation caused hypocalcification amelogenesis imperfecta in a Chinese family

OBJECTIVES

Autosomal-dominant hypocalcification amelogenesis imperfecta (ADHCAI) is a hereditary disease characterized by enamel defects. ADHCAI is mainly caused by nonsense mutations in a gene called family with sequence similarity 83 member H (FAM83H). To study the pathogenesis of ADHCAI, a Chinese ADHCAI family was investigated.

MATERIALS AND METHODS

The ultrastructure of enamel was analyzed by micro-CT and scanning electron microscopy. Whole-exome sequencing (WES) was performed to identify the pathogenic gene. The function of the mutant FAM83H was studied by real-time PCR, western blotting, subcellular localization, and protein degradation pathway analyses.

RESULTS

WES identified a known nonsense mutation (c.1915A > T) in exon 5 of the FAM83H gene, causing a truncated protein (p.Lys639*). However, the cases reported herein exhibited significant differences in the clinical phenotype compared with that the previously reported case. An abnormal enamel rod head structure was observed in affected teeth. In vitro functional studies showed altered protein localization and a decreased protein degradation rate for mutant FAM83H.

CONCLUSIONS

We verified the FAM83H p.Lys639* protein as a gain-of-function variant causing ADHCAI. Abnormal enamel rod head structure was observed in teeth with mutant FAM83H proteins. We also investigated the molecular pathogenesis and presented data on the abnormal degradation of mutant FAM83H proteins.

CLINICAL RELEVANCE

This study helped the family members to understand the disease progression and provided new insights into the pathogenesis of ADHCAI. Due to the large heterogeneity of ADHCAI, this study also provided a genetic basis for individuals who exhibit similar clinical phenotypes.

Individual and Co-Expression Patterns of FAM83H and SCRIB at Diagnosis Are Associated with the Survival of Colorectal Carcinoma Patients

Background: FAM83H is important in teeth development; however, an increasing number of reports have indicated a role for it in human cancers. FAM83H is involved in cancer progression in association with various oncogenic molecules, including SCRIB. In the analysis of the public database, there was a significant association between FAM83H and SCRIB in colorectal carcinomas. However, studies evaluating the association of FAM83H and SCRIB in colorectal carcinoma have been limited. Methods: The clinicopathological significance of the immunohistochemical expression of FAM83H and SCRIB was evaluated in 222 colorectal carcinomas. Results: The expressions of FAM83H and SCRIB were significantly associated in colorectal carcinoma tissue. In univariate analysis, the nuclear expressions of FAM83H and SCRIB and the cytoplasmic expression of SCRIB were significantly associated with shorter survival of colorectal carcinomas. The nuclear expressions of FAM83H and SCRIB and the cytoplasmic expression of SCRIB were independent indicators of shorter cancer-specific survival in multivariate analysis. A co-expression pattern of nuclear FAM83H and cytoplasmic SCRIB predicted shorter cancer-specific survival (p < 0.001) and relapse-free survival (p = 0.032) in multivariate analysis. Conclusions: This study suggests that FAM83H and SCRIB might be used as prognostic markers of colorectal carcinomas and as potential therapeutic targets for colorectal carcinomas.

LncRNA FAM83H-AS1 Contributes to the Radio-resistance and Proliferation in Liver Cancer through Stability FAM83H Protein

BACKGROUND

Liver cancer (LC) is one of China's most common malignant tumors, with a high mortality rate, ranking third leading cause of death after gastric and esophageal cancer. Recent patents propose the LncRNA FAM83H-AS1 has been verified to perform a crucial role in the progression of LC. LncRNA FAM83H-AS1 has been verified to perform a crucial role in the progression of LC. However, the concrete mechanism remains to be pending further investigation.

OBJECTIVE

This study aimed to explore the embedding mechanism of FAM83H-AS1 molecules in terms of radio sensitivity of LC and provide potentially effective therapeutic targets for LC therapy.

METHODS

Quantitative real-time PCR (qRT-PCR) was conducted to measure the transcription levels of genes. Proliferation was determined via CCK8 and colony formation assays. Western blot was carried out to detect the relative protein expression. A xenograft mouse model was constructed to investigate the effect of LncRNA FAM83H-AS1 on tumor growth and radio-sensitivity in vivo.

RESULTS

The levels of lncRNA FAM83H-AS1 were remarkably increased in LC. Knockdown of FAM83H-AS1 inhibited LC cell proliferation and colony survival fraction. Deletion of FAM83H-AS1 increased the sensitivity of LC cells to 4 Gy of X-ray radiation. In the xenograft model, radiotherapy combined with FAM83H-AS1 silencing significantly reduced tumor volume and weight. Overexpression of FAM83H reversed the effects of FAM83H-AS1 deletion on proliferation and colony survival fraction in LC cells. Moreover, the over-expressing of FAM83H also restored the tumor volume and weight reduction caused by the knockdown of FAM83H-AS1 or radiation in the xenograft model.

CONCLUSION

Knockdown of lncRNA FAM83H-AS1 inhibited LC growth and enhanced radiosensitivity in LC. It has the potential to be a promising target for LC therapy.

Identification of a Novel FAM83H Mutation and Management of Hypocalcified Amelogenesis Imperfecta in Early Childhood

Amelogenesis imperfecta (AI) is a heterogeneous group of rare genetic disorders affecting amelogenesis during dental development. Therefore, the molecular genetic etiology of AI can provide information about the nature and progress of the disease. To confirm the genetic etiology of AI in a Korean family with an autosomal dominant inheritance, pedigree and mutational analyses were performed. DNA was isolated from the participating family members and whole-exome sequencing was performed with the DNA sample of the father of the proband. The identified mutation was confirmed by Sanger sequencing. The mutational analysis revealed a novel nonsense mutation in the FAM83H gene (NM_198488.5: c.1363C > T, p.(Gln455*)), confirming autosomal dominant hypocalcified AI. Full-mouth restorative treatments of the affected children were performed after the completion of the deciduous dentition. Early diagnosis of AI can be useful for understanding the nature of the disease and for managing the condition and treatment planning.

Amelogenesis imperfecta in a Chinese family resulting from a FAM83H variation and the effect of FAM83H on the secretion of enamel matrix proteins

OBJECTIVES

To investigate the variant of an amelogenesis imperfecta (AI) family and to explore the function of the FAM83H (family with sequence similarity 83 member H) in the enamel formation.

MATERIALS AND METHODS

We investigated a five-generation Chinese family diagnosed with AI; clinical data was collected, whole-exome sequencing (WES) was conducted to explore the pathogenic gene and variants and Sanger sequencing was used to verify the variants. The three-dimensional protein structures of wild-type and mutant FAM83H were predicted using alpha fold 2. To study the possible regulatory function of Fam83h on amelogenesis, immunolocalization was performed to observe the expression of Fam83h protein in Sprague-Dawley rat postnatal incisors. The mRNA and protein level of amelogenin, enamelin, kallikrein-related peptidase-4 and ameloblastin were also detected after the Fam83h was knocked down by small interfering RNA (siRNA) in HAT-7 cells.

RESULTS

A known nonsense variant (c.973 C > T) in exon 5 of FAM83H gene was found in this family, causing a truncated protein (p.R325X). Immunolocalization of Fam83h in Sprague-Dawley rat postnatal incisors showed that Fam83h protein expression was detected in presecretory and secretory stages. When Fam83h expression was reduced by siRNA, the expression of amelogenin, enamelin, kallikrein-related peptidase-4 decreased. However, the expression of ameloblastin increased.

CONCLUSIONS

FAM83H gene variant (c.973 C > T) causes AI. FAM83H regulates the secretion of enamel matrix proteins and affects ameloblast differentiation.

CLINICAL RELEVANCE

This study provided that FAM83H variants could influence enamel formation and provided new insights into the pathogenesis of AI.

A Recurrent FAM83H Mutation in an Extended Colombian Family and Variable Craniofacial Phenotypes

Amelogenesis imperfecta (AI) is a collection of rare genetic disorders affecting the quantity and/or quality of the tooth enamel. AI can be classified into three major types according to the clinical phenotype: hypoplastic, hypocalcified, and hypomatured. Among them, the hypocalcified type shows the weakest physical properties, leaving rough and discolored enamel surfaces after tooth eruption. To date, mutations in the FAM83H gene are responsible for the autosomal-dominant hypocalcified AI. In this study, we recruited a four-generation Colombian family with hypocalcified AI and identified a recurrent nonsense mutation in the FAM83H gene (NM_198488.5:c.1289C>A, p.(Ser430 *)) by candidate gene sequencing. Cephalometric analyses revealed the anterior open bite that occurred in the proband is not correlated with the AI in this family.

Missense Mutation in Fam83H Gene in Iranian Patients with Amelogenesis Imperfecta

BACKGROUND

Amelogenesis Imperfecta (AI) is a disorder of tooth development where there is an abnormal formation of enamel or the external layer of teeth. The aim of this study was to screen mutations in the four most important candidate genes, ENAM, KLK4, MMP20 and FAM83H responsible for amelogenesis imperfect.

METHODS

Geneomic DNA was isolated from five Iranian families with 22 members affected with enamel malformations. The PCR amplifications were typically carried out for amplification the coding regions for AI patients and unaffected family members. The PCR products were subjected to direct sequencing. The pedigree analysis was performed using Cyrillic software.

RESULTS

One family had four affected members with autosomal dominant hypocalcified amelogenesis imperfecta (ADHPCAI); pedigree analysis revealed four consanguineous families with 18 patients with autosomal recessive hypoplastic amelogenesis imperfecta (ARHPAI). One non-synonymous single-nucleotide substitution, c.1150T>A, p. Ser 342Thr was identified in the FAM83H, which resulted in ADHCAI. Furthermore, different polymorphisms or unclassified variants were detected in MMP20, ENAM and KLK4.

CONCLUSION

Our results are consistent with other studies and provide further evidence for pathogenic mutations of FAM83H gene. These findings suggest different loci and genes could be implicated in the pathogenesis of AI.

Tooth ultrastructure changes induced by a nonsense mutation in the FAM83H gene: insights into the diversity of amelogenesis imperfecta

OBJECTIVES

The current research on single-nucleotide polymorphism (SNP) mutation sites at different positions of the FAM83H gene and their phenotypic changes leading to amelogenesis imperfecta (AI) is inconsistent. We identified a previously reported heterozygous nonsense mutation c.1192C>T (p.Q398*) in the FAM83H gene and conducted a comprehensive analysis of the dental ultrastructure and chemical composition changes induced by this mutation. Additionally, we predicted the protein feature affected by this mutation site. The aim was to further deepen our understanding of the diversity of AI caused by different mutation sites in the FAM83H gene.

METHODS

Whole-exome sequencing (WES) and Sanger sequencing were used to confirm the mutation sites. Physical features of the patient's teeth were investigated using various methods including cone beam computer tomography (CBCT), scanning electron microscopy (SEM), contact profilometry (roughness measurement), and a nanomechanical tester (nanoindentation measurement). The protein features of wild-type and mutant FAM83H were predicted using bioinformatics methods.

RESULTS

One previously discovered FAM83H heterozygous nonsense mutation c.1192C>T (p.Q398*) was detected in the patient. SEM revealed inconsistent dentinal tubules, and EDS showed that calcium and phosphorus were lower in the patient's dentin but higher in the enamel compared to the control tooth. Roughness measurements showed that AI patients' teeth had rougher occlusal surfaces than those of the control tooth. Nanoindentation measurements showed that the enamel and dentin hardness values of the AI patients' teeth were both significantly reduced compared to those of the control tooth. Compared to the wild-type FAM83H protein, the mutant FAM83H protein shows alterations in stability, hydrophobicity, secondary structure, and tertiary structure. These changes could underlie functional differences and AI phenotype variations caused by this mutation site.

CONCLUSIONS

This study expands the understanding of the effects of FAM83H mutations on tooth structure.

CLINICAL RELEVANCE

Our study enhances our understanding of the genetic basis of AI and may contribute to improved diagnostics and personalized treatment strategies for patients with FAM83H-related AI.

FAM83H regulated by glis3 promotes triple-negative breast cancer tumorigenesis and activates the NF-κB signaling pathway

Triple-negative breast cancer (TNBC) is a highly aggressive and invasive form of breast cancer (BC) with a high mortality rate and a lack of effective targeted drugs. Family with sequence similarity 83 member H (FAM83H) is critically implicated in tumorigenesis. However, the potential role of FAM83H in TNBC remains elusive. Here, we discovered that FAM83H exhibited high expression in tumor tissues of patients with TNBC and was associated with TNM stage. Gain- or loss-of-function experiments were conducted to explore the biological role of FAM83H in TNBC. Subsequently, functional enrichment analysis confirmed that FAM83H overexpression promoted TNBC cell proliferation, invasion, migration and epithelial-mesenchymal transition (EMT), accompanied by upregulation of cyclin E, cyclin D, Vimentin, N-cadherin and Slug. As observed, FAM83H knockdown showed anti-cancer effects, such as fostering apoptosis and inhibiting tumorigenicity and metastasis of TNBC cells. Mechanistically, FAM83H activated the NF-κB signaling pathway. Moreover, a dual-luciferase reporter assay demonstrated that GLIS family zinc finger 3 (GLIS3) bound to the promoter of FAM83H and enhanced its transcription. Notably, overexpression of GLIS3 significantly stimulated TNBC cell proliferation and invasion, and all of this was reversed by rescue experiments involving the knockdown of FAM83H. Overall, FAM83H exacerbates tumor progression, and in-depth understanding of FAM83H as a therapeutic target for TNBC will provide clinical translational potential for intervention therapy.

FAM83H Expression Is Associated with Tumor-Infiltrating PD1-Positive Lymphocytes and Predicts the Survival of Breast Carcinoma Patients

BACKGROUND

FAM83H has been implicated in cancer progression, and PD1 is an important target for anti-cancer immune checkpoint therapy. Recent studies suggest an association between FAM83H expression and immune infiltration. However, studies on the roles of FAM83H and its relationship with PD1 in breast carcinomas have been limited.

METHODS

Immunohistochemical expression of FAM83H and PD1 and their prognostic significance were evaluated in 198 breast carcinomas.

RESULTS

The expression of FAM83H in cancer cells was significantly associated with the presence of PD1-positive lymphoid cells within breast carcinoma tissue. Individual and co-expression patterns of nuclear FAM83H and PD1 were significantly associated with shorter survival of breast carcinomas in univariate analysis. In multivariate analysis, the expression of nuclear FAM83H (overall survival, p < 0.001; relapse-free survival, p = 0.003), PD1 (overall survival, p < 0.001; relapse-free survival, p = 0.003), and co-expression patterns of nuclear FAM83H and PD1 (overall survival, p < 0.001; relapse-free survival, p < 0.001) were the independent indicators of overall survival and relapse-free survival of breast carcinoma patients.

CONCLUSIONS

This study suggests a close association between FAM83H expression and the infiltration of PD1-positive lymphoid cells in breast carcinomas and their expression as the prognostic indicators for breast carcinoma patients, and further studies are needed to clarify this relationship.

Expression of AMELX, AMBN, ENAM, TUFT1, FAM83H and MMP20 Genes in Buccal Epithelial Cells from Patients with Molar Incisor Hypomineralization (MIH)-A Pilot Study

Molar incisor hypomineralization (MIH) is a developmental defect that affects the enamel tissue of permanent teeth. Clinicians may observe a range of opacities in the affected teeth, varying from white to creamy, yellow, and brown. Of particular interest is an etiology of MIH that has not been rigorously elucidated. Researchers believe that there are many potential etiological factors with strong genetic and/or epigenetic influence. The primary factors contributing to the risk of MIH development include specific medical conditions and circumstances. These encompass prematurity, cesarean delivery, perinatal hypoxia, and various health issues such as measles, urinary tract infections, otitis media, gastrointestinal disorders, bronchitis, kidney diseases, pneumonia, and asthma. Although genetic research in this area has received substantial attention, the investigation of epigenetic factors remains comparatively underexplored. Special attention is given to genes and their protein products involved in amelogenesis. Examples of such genes are AMELX, AMBN, ENAM, TUFT1, FAM83H, and MMP20. The median relative FAM83H gene expression in the control group was 0.038 (0.031-0.061) and 0.045 (0.032-0.087) in the study group in buccal swabs. The median relative TUFT1 gene expression in the control group was 0.328 (0.247-0.456) and 0.704 (0.334-1.183) in the study group in buccal swabs. Furthermore, children with MIH had significantly higher TUFT1 expression levels compared to the control group (p-value = 0.0043). Alterations in the expression of the TUFT1 and FAM83H genes could be contributing factors to MIH pathogenesis. Nonetheless, further investigation is essential to comprehensively elucidate the roles of all analyzed genes in the pathogenesis of MIH.