JMJD2A sensitizes gastric cancer to chemotherapy by cooperating with CCDC8.

BACKGROUND: Jumonji domain-containing protein 2A (JMJD2A) of the JMJD2 family of histone lysine demethylases has been implicated in tumorigenesis. However, its expression and role in gastric cancer (GC) drug resistance remain unknown. Here, we investigated the role of JMJD2A in GC chemotherapeutic susceptibility and its clinical relevance in GC. METHODS: We selected 12 relevant genes from previously identified gene signatures that can predict GC susceptibility to docetaxel, cisplatin, and S-1 (DCS) therapy. Each gene was knocked down using siRNA in GC cell lines, and cell viability assays were performed. JMJD2A expression in GC cell lines and tissues was assessed using qRT-PCR and immunohistochemistry, respectively. A JMJD2A downstream target related to drug susceptibility was examined using whole-gene expression array and immunoprecipitation. RESULTS: Among the 12 candidate genes, down-regulation of JMJD2A showed the maximum effect on GC susceptibility to anti-cancer drugs and increased the IC50 values for 5-FU, cisplatin, and docetaxel 15.3-, 2.7-, and 4.0-fold, respectively. JMJD2A was universally expressed in 12 GC cell lines, and its overexpression in GC tissue was positively correlated with tumor regression in 34 DCS-treated patients. A whole-gene expression array of JMJD2A-knockdown GC cells demonstrated a significant decrease in the expression of pro-apoptotic coiled-coil domain containing 8 (CCDC8), a downstream target of JMJD2A. Direct interaction between CCDC8 and JMJD2A was verified using immunoprecipitation. CCDC8 inhibition restored drug resistance to docetaxel, cisplatin, and S-1. CONCLUSIONS: Our results indicate that JMJD2A is a novel epigenetic factor affecting GC chemotherapeutic susceptibility, and JMJD2A/CCDC8 is a potential GC therapeutic target.

3M syndrome patient with a novel mutation: A case report.

BACKGROUND: A rare autosomal recessive genetic disorder, 3M syndrome, is characterized by severe intrauterine and postnatal growth retardation. Children with 3M syndrome typically exhibit short stature, facial deformities, long tubular bones, and high vertebral bodies but generally lack mental abnormalities or other organ damage. Pathogenic genes associated with 3M syndrome include CUL7, OBSL1 and CCDC8. The clinical and molecular characteristics of patient with 3M syndrome are unique and serve as important diagnostic indicators. CASE SUMMARY: In this case, the patient displayed square shoulders, scoliosis, long slender tubular bones, and normal neurological development. Notably, the patient did not exhibit the typical dysmorphic facial features, relative macrocephaly, or growth retardation commonly observed in individuals with 3M syndrome. Whole exon sequencing revealed a novel heterozygous c.56681+1G>C (Splice-3) variant and a previously reported nonsense heterozygous c.3341G>A (p.Trp1114Ter) variant of OBSL1. Therefore, it is important to note that the clinical features of 3M syndrome may not always be observable, and genetic confirmation is often required. Additionally, the identification of the c.5683+1G>C variant in OBSL1 is noteworthy because it has not been previously reported in public databases. CONCLUSION: Our study identified a new variant (c.5683+1G>C) of OBSL1 that contributes to expanding the molecular profile of 3M syndrome.

Construction of circRNA-based ceRNA network and its prognosis-associated subnet of clear cell renal cell carcinoma.

Circular RNAs (circRNAs) are novel biomarkers of various cancers. CircRNAs can sponge miRNAs and regulate target mRNAs, which was called competing endogenous RNAs (ceRNA). This study was designed to identify circRNAs related to patients with clear cell renal cell carcinoma (ccRCC) and the first to select three independent Gene Expression Omnibus microarrays covering circRNAs, miRNAs, and mRNAs for multiple analyses. The data of clinical cases applied in our study were obtained from The Cancer Genome Atlas. We successfully conducted a circRNA/miRNA/mRNA ceRNA network related to ccRCC patients via R software and Cytoscape including 8 circRNAs, 6 miRNAs, and 49 mRNAs. The prognosis-associated subnet covered 8 circRNAs, 6 miRNAs, and 22 mRNAs. Quantitative real-time PCR was applied to measure our prediction in three renal cell lines and 23 pairs of tissues. Small interfering RNA targeting the back-splice region of hsa_circ_0001167 was further implied to confirm the regulation. Ultimately, hsa_circ_0001167/hsa-miR-595/CCDC8 regulatory axis was identified in this study, which may serve as prognostic indicators. Lower levels of hsa_circ_0001167 and CCDC8 were potentially correlated with worse patient survival.

G9a Regulates Cell Sensitivity to Radiotherapy via Histone H3 Lysine 9 Trimethylation and CCDC8 in Lung Cancer.

PURPOSE: To investigate the role and underlying mechanism of G9a and CCDC8 in lung cancer radioresistance. METHODS: Western blotting assays were used for G9a, CCDC8, H3K9me3 expression detection. MTT assays and clone formation assays were used for measuring cell proliferation activities. Flow cytometry assays were used for cell apoptosis detection. The enrichment of H3K9me3 in CCDC8 promoter was measured by chromatin immunoprecipitation assay. RESULTS: G9a and G9a-mediated H3K9me3 are upregulated in radioresistant lung cancer cells (A549/IR cell and XWLC-05/IR cell). Blocking G9a not only promotes radiosensitivity of A549/IR cell and XWLC-05/IR cell but also reduces aggressive behavior of radioresistant A549 cell/IR and XWLC-05/IR cell. In addition, G9a-controlled H3K9me3 is able to binding to the promoter of tumor suppressor gene CCDC8 and suppresses CCDC8 expression. CCDC8 dysregulation is responsible for G9a-mediated radioresistance of A549/IR cell and XWLC-05/IR cell. CONCLUSION: G9a and H3K9me3 contribute to the lung cancer radioresistance via modulating CCDC8 expression.

Two Siblings with a Mutation in CCDC8 Presenting with Mild Short Stature: A Case of 3-M Syndrome.

BACKGROUND: Short stature can be caused by mutations in a multitude of different genes. 3-M syndrome is a rare growth disorder marked by severe pre- and postnatal growth retardation along with subtle dysmorphic features. There have only been 2 prior reports of mutations in CCDC8 causing 3-M syndrome. METHODS: Two patients presenting with mild short stature underwent whole exome sequencing. The mutation was confirmed via Sanger sequencing. We compare the clinical characteristics of our 2 patients to patients previously reported with mutations in the same gene. RESULTS: Exome sequencing identified a homozygous frameshift mutation in CCDC8 in both patients. They presented with a much milder phenotype than previously described patients with the same mutation. CONCLUSION: In this study, we report a case of 2 sisters with relatively mild short stature who were found via exome sequencing to carry a previously reported homozygous mutation in CCDC8. These patients expand the anthropometric phenotype of 3-M syndrome and demonstrate the power of exome sequencing in the diagnosis of children with short stature. 3-M syndrome should be considered in children with mild skeletal abnormalities, normal/high growth hormone-IGF axis parameters, and normal intelligence.

Coiled-coil domain-containing protein 8 inhibits the invasiveness and migration of non-small cell lung cancer cells.

Lung cancer has always been the leading cause of death among patients with malignant tumors, and the majority of these patients die because of cancer cell invasion and metastasis. Previous studies have implicated coiled-coil domain-containing protein 8 (CCDC8) as a tumor suppressor in several types of cancer, such as breast and prostate cancers. However, the expression levels or functions of CCDC8 in lung cancer have not been elucidated. Here, we used immunohistochemical staining to measure CCDC8 expression in 147 samples from tumors and 30 samples from the adjacent normal lung tissues of patients with non-small cell lung cancer. CCDC8 was shown to be located predominantly in the cytoplasm and partially on the cell membrane, and its expression level was significantly lower in lung cancer samples than that in the adjacent normal lung tissues (P=.001). CCDC8 expression was closely related to tumor differentiation (P=.039), tumor-node-metastasis stage (P=.009), lymph node metastasis (P=.038), and prognosis (P=.043) of lung cancer. Transfection of A549 cells with CCDC8 significantly reduced cell invasion and migration (P<.05), whereas the invasiveness and migration capacity in CCDC8-knockdown A549 cells were significantly increased in comparison with the control cells (P<.05). Furthermore, we demonstrated that CCDC8 can downregulate the expression of Snail and upregulate the expression of E-cadherin by inhibiting p-P38 and p-IκBα. Collectively, CCDC8 may suppress the invasion and metastasis of lung cancer cells, and it may represent a promising therapeutic target for non-small cell lung cancer.

3-M syndrome: a growth disorder associated with IGF2 silencing.

3-M syndrome is an autosomal recessive disorder characterised by pre- and post-natal growth restriction, facial dysmorphism, normal intelligence and radiological features (slender long bones and tall vertebral bodies). It is known to be caused by mutations in the genes encoding cullin 7, obscurin-like 1 and coiled-coil domain containing 8. The mechanisms through which mutations in these genes impair growth are unclear. The aim of this study was to identify novel pathways involved in the growth impairment in 3-M syndrome. RNA was extracted from fibroblast cell lines derived from four 3-M syndrome patients and three control subjects, hybridised to Affymetrix HU 133 plus 2.0 arrays with quantitative real-time PCR used to confirm changes found on microarray. IGF-II protein levels in conditioned cell culture media were measured by ELISA. Of the top 10 downregulated probesets, three represented IGF2 while H19 was identified as the 23rd most upregulated probeset. QRT-PCR confirmed upregulation of H19 (P<0.001) and downregulation of IGF2 (P<0.001). Levels of IGF-II secreted into conditioned cell culture medium were higher for control fibroblasts than those for 3-M fibroblasts (10.2±2.9 vs 0.6±0.9 ng/ml, P<0.01). 3-M syndrome is associated with a gene expression profile of reduced IGF2 expression and increased H19 expression similar to that found in Silver-Russell syndrome. Loss of autocrine IGF-II in the growth plate may be associated with the short stature seen in children with 3-M syndrome.