Meta-analysis of the expression of the mitosis-related gene Fam83D

The FBXW7-binding sites on FAM83D are potential targets for cancer therapy

Increasing evidence shows the oncogenic function of FAM83D in human cancer, but how FAM83D exerts its oncogenic function remains largely unclear. Here, we investigated the importance of FAM83D/FBXW7 interaction in breast cancer (BC). We systematically mapped the FBXW7-binding sites on FAM83D through a comprehensive mutational analysis together with co-immunoprecipitation assay. Mutations at the FBXW7-binding sites on FAM83D led to that FAM83D lost its capability to promote the ubiquitination and proteasomal degradation of FBXW7; cell proliferation, migration, and invasion in vitro; and tumor growth and metastasis in vivo, indicating that the FBXW7-binding sites on FAM83D are essential for its oncogenic functions. A meta-evaluation of FAM83D revealed that the prognostic impact of FAM83D was independent on molecular subtypes. The higher expression of FAM83D has poorer prognosis. Moreover, high expression of FAM83D confers resistance to chemotherapy in BCs, which is experimentally validated in vitro. We conclude that identification of FBXW7-binding sites on FAM83D not only reveals the importance for FAM83D oncogenic function, but also provides valuable insights for drug target.

Inhibition of FAM83D displays antitumor effects in glioblastoma via down-regulation of the AKT/Wnt/β-catenin pathway

Up-regulation of family with sequence similarity 83 member D (FAM83D) has been acknowledged as a vital contributor for the carcinogenesis of numerous cancers. The relevance of FAM83D in glioblastoma (GBM), however, is not well understood. This current work aimed to determine the possible roles and mechanisms of FAM83D in GBM. By analyzing The Cancer Genome Atlas (TCGA) data, we found dramatic increases in FAM83D expression in GBM tissue. We also observed elevated levels of FAM83D in the clinical specimens of GBM. In vitro data showed that silencing FAM83D resulted in remarkable antitumor effects via inhibiting the proliferation, invasion and epithelial-mesenchymal transition of GBM cells. Moreover, the knockdown of FAM83D improved sensitivity to the chemotherapy drug temozolomide. In-depth mechanism research revealed that the silencing of FAM83D strikingly decreased the phosphorylation levels of AKT and glycogen synthase kinase-3β, and prohibited activation of the Wnt/β-catenin pathway. The suppression of AKT abolished FAM83D-mediated activation of the Wnt/β-catenin pathway. The re-expression of β-catenin reversed FAM83D-silencing-induced antitumor effects in GBM cells. In addition, GBM cells with FAM83D silencing exhibited reduced tumorigenic potential in vivo. Overall, the data from this work show that the inhibition of FAM83D displays antitumor effects in GBM via down-regulation of the AKT/Wnt/β-catenin pathway and propose FAM83D as a new therapeutic target for GBM.

Dynamic expression of FAM83D in peripheral organs at different ages in mice

The family with sequence similarity 83 member (FAM83D) plays important role in the process of cell division as well as tumour progression. However, the role of FAM83D in tissue development was not well explored. Here, we assessed transcriptional levels of FAM83D and other possibly related genes in organs of mice at different ages and methylation level of FAM83D promoter. Our results indicate the trend of FAM83D expression in mouse testis, liver, lung and small intestine, and its relationship to CYCLINB1 and KI67. Finally, we found no effect of promoter methylation status on FAM83D expression during mice development.

G3BP1 interacts with YWHAZ to regulate chemoresistance and predict adjuvant chemotherapy benefit in gastric cancer

BACKGROUND

A large proportion of gastric cancer patients are susceptible to chemoresistance, while the underlying mechanism remains obscure. Stress granules (SGs) play a self-defence role for tumour cells in inhibiting chemotherapy-induced apoptosis. As an SG assembly effector, G3BP1 (Ras-GTPase-activating protein SH3 domain-binding protein) has been reported to be overexpressed in gastric cancer; thus, here we aim to explore its potent roles in gastric cancer chemoresistance.

METHODS

Kaplan–Meier analysis was used to compare survival rates in gastric cancer patients with different G3BP1 expression. The influence of G3BP1 on gastric cancer cell chemoresistance and apoptosis were evaluated by in vitro and in vivo approaches. The interaction between G3BP1 and YWHAZ was assessed by immunohistochemistry, immunoprecipitation and immunofluorescence.

RESULTS

G3BP1 was associated with the poor outcome of gastric cancer patients who received adjuvant chemotherapy. G3BP1 knockdown significantly increased the sensitivity of gastric cancer cells to chemotherapy drugs. Mechanically, cell apoptosis and pro-apoptotic-associated molecules were significantly elevated upon G3BP1 depletion. Gene co-expression network analyses identified YWHAZ as the critical interlayer of G3BP1; as a result, G3BP1 interacted with YWHAZ to sequester Bax into the cytoplasm. Clinically, G3BP1^highYWHAZ^high gastric cancer patients displayed the worst outcome compared with other patients after chemotherapy.

CONCLUSIONS

The expression of G3BP1 and YWHAZ could predict the adjuvant chemotherapy benefit in gastric cancer patients.

Fam83d modulates MAP kinase and AKT signaling and is induced during neurogenic skeletal muscle atrophy

Skeletal muscle atrophy is a serious health condition that can arise due to aging, cancer, corticosteroid exposure, and denervation. Previous work comparing gene expression profiles in control and denervated muscle tissue revealed for the first time that Fam83d is expressed in skeletal muscle and is significantly induced in response to denervation. Quantitative PCR and Western blot analysis found that Fam83d is more highly expressed in proliferating myoblasts compared to differentiated myotubes. Characterization of the transcriptional regulation of Fam83d showed that ectopic expression of myogenic regulatory factors inhibits Fam83d reporter gene activity. To assess where Fam83d is localized in the cell, Fam83d was fused with green fluorescent protein, expressed in C₂C₁₂ cells, and found to localize in a punctate manner to the cytoplasm of muscle cells. To assess function, Fam83d was ectopically expressed in cultured muscle cells and markers of muscle cell differentiation, the MAP Kinase signaling pathway, and the AKT signaling pathway were analyzed. Fam83d overexpression resulted in significant repression of myosin heavy chain and myogenin expression, while phosphorylated ERK and AKT were also significantly repressed. Interestingly, inhibition of the 26S proteasome and the MAP kinase signaling pathway both resulted in stabilization of Fam83d during muscle cell differentiation. Finally, Fam83d has a putative phospholipase D-like domain that appears to be necessary for destabilizing casein kinase Iα and inhibiting ERK phosphorylation in cultured myoblasts. The discovery that Fam83d is expressed in skeletal muscle combined with the observation that Fam83d, a potential modulator of MAP kinase and AKT signaling, is induced in response to neurogenic atrophy helps further our understanding of the molecular and cellular events of skeletal muscle wasting.

FAM83D inhibits autophagy and promotes proliferation and invasion of ovarian cancer cells via PI3K/AKT/mTOR pathway

Ovarian cancer is one of the most lethal malignant tumors in women. The family with sequence similarity 83, member D (FAM83D) plays an important role in several cancers, but its function and underlying mechanism in ovarian cancer remain unknown. To investigate the role of FAM83D in ovarian cancer, the expression of FAM83D was determined by immunohistochemistry in tissue microarray slide. Cellular proliferation and invasion were detected by 5-Ethynyl-2'-deoxyuridine assays and transwell invasion assays. The correlations between FAM83D and autophagy were detected by western blot analysis and confocal microscopy. Western blot analysis was used to identify the protein expression of FAM83D, phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), mammalian target of rapamycin (mTOR) and Sequestosome 1 (P62). Tumorigenesis in nude mice was used to explore the function of FAM83D in vivo. We found high expression level of FAM83D in ovarian cancer tissues as compared to the normal ovarian tissues. Knockdown of FAM83D in SKOV3 cells enhanced autophagy and inhibited the proliferation and invasion in vitro, whereas ectopic expression of FAM83D in A2780 cells exerted an opposite effect. Mechanistically, overexpression of FAM83D activated the PI3K/AKT/mTOR pathway, and Torin1 could suppress FAM83D-induced cell proliferation and invasion. In vivo, overexpression FAM83D promoted tumor growth. Overall, FAM83D promoted ovarian cancer cell invasion and proliferation, while inhibited autophagy via the PI3K/AKT/mTOR signaling pathway. Our results suggest that FAM83D may be a candidate oncogene in ovarian cancer, which provides a fresh perspective of FAM83D in ovarian cancer.

FAM83D is associated with gender, AJCC stage, overall survival and disease-free survival in hepatocellular carcinoma

Prognostic significance of family with sequence similarity 83, member D (FAM83D) in hepatocellular carcinoma (HCC) patients has not been well-investigated using Gene Expression Omnibus (GEO) series and TCGA database, we compared FAM83D expression levels between tumor and adjacent tissues, and correlated FAM83D in tumors with outcomes and clinico-pathological features in HCC patients. Validated in GSE33006, GSE45436, GSE84402 and TCGA, FAM83D was significantly overexpressed in tumor tissues than that in adjacent tissues (all P<0.01). FAM83D up-regulation was significantly associated with worse overall survival (OS) and disease-free survival (DFS) in HCC patients (Log rank P=0.00583 and P=4.178E-04, respectively). Cox analysis revealed that FAM83D high expression was significantly associated with OS in HCC patients [hazard ratio (HR) = 1.44, 95% confidence interval (CI) = 1.005-2.063, P=0.047]. Additionally, patients deceased or recurred/progressed had significantly higher FAM83D mRNA levels than those living or disease-free (P=0.0011 and P=0.0238, respectively). FAM83D high expression group had significantly more male patients and advanced American Joint Committee on Cancer (AJCC) stage cases (P=0.048 and P=0.047, respectively). FAM83D mRNA were significantly overexpressed in male (P=0.0193). Compared with patients with AJCC stage I, those with AJCC stage II and stage III-IV had significantly higher FAM83D mRNA levels (P = 0.0346 and P=0.0045, respectively). In conclusion, overexpressed in tumors, FAM83D is associated with gender, AJCC stage, tumor recurrence and survival in HCC.

FAM83 proteins: Fostering new interactions to drive oncogenic signaling and therapeutic resistance

The FAM83 proteins were recently identified as novel transforming oncogenes that function as intermediaries in EGFR/RAS signaling. Using two distinct forward genetics screens, the Bissell and Jackson laboratories uncovered the importance of the FAM83 proteins in promoting resistance to EGFR tyrosine kinase inhibitors and therapies targeting downstream EGFR signaling effectors. The discovery of this novel oncogene family using distinct genetic screens provides compelling evidence that the FAM83 proteins are key oncogenic players in cancer-associated signaling when they are overexpressed or dysregulated. Consistent with a role in oncogenic transformation, the FAM83 genes are frequently overexpressed in diverse human cancer specimens. Importantly, ablation of numerous FAM83 members results in a marked suppression of cancer-associated signaling and loss of tumorigenic potential. Here, we review the current knowledge of the FAM83 proteins’ involvement in cancer signaling and discuss the potential mechanisms by which they contribute to tumorigenesis. Both redundant activities shared by all 8 FAM83 members and non-redundant activities unique to each member are highlighted. We discuss the promise and challenges of the FAM83 proteins as novel points of attack for future cancer therapies.

FAM83D, a microtubule-associated protein, promotes tumor growth and progression of human gastric cancer

FAM83D, a microtubule-associated protein (MAP), is overexpressed in diverse types of human cancer. The expression and critical role of FAM83D in human gastric cancer (GC), however, remains largely unknown. Here, we conducted molecular, cellular and clinical analyses to evaluate the functional link of FAM83D to GC. FAM83D expression was elevated in gastric tumors, and its expression strongly correlated with lymph node metastasis and TNM stage. In addition, over-expression of FAM83D in GC cell lines enhanced cell proliferation, cycle progression, migration, invasion, as well as tumor growth and metastatic dissemination in vivo. Furthermore, FAM83D exhibited a strong cell cycle correlated expression. The knockdown of FAM83D inhibited the regrowth of microtubules in GC cells. FAM83D was co-immunoprecipitated with HMMR, TPX2, and AURKA, a set of drivers of mitosis progression. Taken together, our results demonstrate FAM83D as an important player in the development of human gastric cancer, and as a potential therapeutic target for the treatment of cancer.

Prognostic significance of FAM83D gene expression across human cancer types

The family with sequence similarity 83, member D (FAM83D) gene has been proposed as a new prognostic marker for breast cancer. Here we further evaluate the prognostic significance of FAM83D expression in different breast cancer subtypes using a meta-analysis. Patients with higher FAM83D mRNA levels have significantly decreased overall and metastatic relapse-free survival, particularly in the group of patients with ER-positive, or luminal subtype tumors. We also assessed FAM83D alterations and its prognostic significance across 22 human cancer types using The Cancer Genome Atlas (TCGA). FAM83D is frequently gained in the majority of human cancer types, resulting in the elevated expression of FAM83D. Higher levels of FAM83D mRNA expression are significantly associated with decreased overall survival in several cancer types. Finally, we demonstrate that TP53 mutation in human cancers is coupled to a significant increase in the expression of FAM83D, and that a higher level of FAM83D expression is positively correlated with an increase in genome instability in many cancer types. These results identify FAM83D as a potential novel oncogene across multiple human cancer types.

Upregulation of FAM83D affects the proliferation and invasion of hepatocellular carcinoma

The identification of potential oncogenes plays an important role in finding novel therapeutic targets for many cancers, including hepatocellular carcinoma (HCC), which is one of the most common cancers worldwide. In our previous research, using microarray technology, we found that FAM83D was overexpressed in HCCs. However, whether the overexpression of FAM83D contributes to hepatocarcinogenesis remains unclear. In this study, we found that FAM83D was significantly upregulated in 76.6% (167 of 218) of the HCC specimens at the mRNA level and in 69.44% (50 of 72) of the HCC specimens at the protein level compared with adjacent non-cancerous liver specimens, as indicated by RT-PCR and immunohistochemical staining, respectively. The FAM83DmRNA expression level was positively correlated with the level of alpha-fetoprotein (AFP) (≥100 ng/ml), the clinical TNM stage, the presence of a portal vein tumor thrombus (PVTT), disease-free survival (DFS) and the overall survival (OS) time of the HCC patients (P < 0.05). Knocking down FAM83D significantly promoted the growth of Huh7 and HepG2 cells, as demonstrated in an RNA interference assay. Moreover, the DNA methylation status of the FAM83D promoter was significantly reduced in the HCC specimens with overexpression of FAM83D gene. Our data suggest that the upregulation of FAM83D, a potential oncotarget gene, may be triggered by epigenetic events and can contribute to hepatocarcinogenesis.

Multi-omics approach to infer cancer therapeutic targets on chromosome 20q across tumor types

The identification of good targets is a critical step for the development of targeted therapies for cancer treatment. Here, we used a multi-omics approach to delineate potential targets on chromosome 20q, which frequently shows a complex pattern of DNA copy number amplification in many human cancers suggesting the presence of multiple driver genes. By comparing the amounts of individual mRNAs in cancer from 11 different human tissues with those in their corresponding normal tissues, we identified 18 genes that were robustly elevated across human cancers. Moreover, we found that higher expression levels of a majority of these genes were associated with poor prognosis in many human cancer types. Using DNA copy number and expression data for all 18 genes obtained from The Cancer Genome Atlas project, we discovered that amplification is a major mechanism driving overexpression of these 18 genes in the majority of human cancers. Our integrated analysis suggests that 18 genes on chromosome 20q might serve as novel potential molecular targets for targeted cancer therapy.

Decreased expression of EFS is correlated with the advanced prostate cancer

Prostate cancer is the most frequently diagnosed malignant neoplasm in men in the developed countries. Although the progression of prostate cancer and the processes of invasion and metastasis by tumor cells are comparatively well understood, the genes involved in these processes are not fully determined. Therefore, a common area of research interest is the identification of novel molecules that are involved in these processes. In the present study, we have used in silico and experimental approaches to compare the expression of embryonal Fyn-associated substrate (EFS) between normal prostate and prostate cancer. We showed that EFS expression is remarkably downregulated in prostate cancer cells, compared to normal prostate cells. We also found that decreased expression of EFS in prostate cancer cells is due to DNA methylation. In addition, we showed that high EFS expression is important to suppress a malignant behavior of prostate cancer cells. Therefore, we suggest that EFS should be considered as a novel tumor suppressor gene in prostate cancer.

Identification of new genes downregulated in prostate cancer and investigation of their effects on prognosis

Prostate cancer is the most common noncutaneous malignant neoplasm in men in the Western countries. It is well established that genetic and epigenetic alterations are common events in prostate cancer, which may lead to aberrant expression of critical genes. Most of the studies are focused on the overexpressed or duplicated genes in prostate cancer. However, it is known that some of the differentially expressed genes in prostate cancer are downregulated. Since the inventory of downregulated genes is incomplete, we performed in silico approaches to reveal the novel prostate cancer downregulated genes. Moreover, we also investigated for a possible link between the expression of the downregulated genes and tumor grade, recurrence, metastasis, or survival status in prostate cancer. Our results showed that the expression of GSTP1 and AOX1 are downregulated in prostate cancer, in concordance with previous reports. Moreover, we showed that TPM2, CLU, and COL4A6 mRNA levels are downregulated in prostate cancer. Further, we found a significant negative correlation between the expression of the above-mentioned genes and the prognosis of prostate cancer.