FAM83D knockdown regulates proliferation, migration and invasion of colorectal cancer through inhibiting FBXW7/Notch-1 signalling pathway

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.

METTL3 regulates FAM83D m6A modification to accelerate tumorigenesis of triple-negative breast cancer via the Wnt/β-catenin pathway

N6-methyladenosine (m6A) modification, the most abundant methylation modification on eukaryotic mRNAs, was implicated in the tumourigenesis. This study aimed to explore the role of methyltransferase like 3 (METTL3) in triple-negative breast cancer progression and its underlying mechanisms. FAM83D was markedly elevated in triple-negative breast cancer tissues and cells, and high expression of FAM83D was related to the poor prognosis of triple-negative breast cancer patients. FAM83D knockdown significantly retarded cell proliferation, invasion, stemness, and accelerated cell apoptosis in triple-negative breast cancer cells. On the contrary, overexpression of FAM83D promoted the malignant behaviors. METTL3 could interact with FAM83D and mediate m6A modification of FAM838D. Moreover, METTL3 positively regulated FAM83D expression, and FAM83D overexpression could block the inhibition effects of MRTTL3 knockdown on the malignant behaviors. METTL3 knockdown decreased FAM83D expression to inhibit the Wnt/β-catenin pathway. In addition, knockdown of FAM83D also showed the repressive effects on tumor growth in triple-negative breast cancer in vivo. These findings suggested that METTL3 could modulate FAM83D protein expression through m6A modification to aggravate triple-negative breast cancer progression via the Wnt/β-catenin pathway.

Dpep Inhibits Cancer Cell Growth and Survival via Shared and Context-Dependent Transcriptome Perturbations

Dpep is a cell-penetrating peptide targeting transcription factors ATF5, CEBPB, and CEBPD, and that selectively promotes the apoptotic death of multiple tumor cell types in vitro and in vivo. As such, it is a potential therapeutic. To better understand its mechanism of action, we used PLATE-seq to compare the transcriptomes of six cancer cell lines of diverse origins before and after Dpep exposure. This revealed a context-dependent pattern of regulated genes that was unique to each line, but that exhibited a number of elements that were shared with other lines. This included the upregulation of pro-apoptotic genes and tumor suppressors as well as the enrichment of genes associated with responses to hypoxia and interferons. Downregulated transcripts included oncogenes and dependency genes, as well as enriched genes associated with different phases of the cell cycle and with DNA repair. In each case, such changes have the potential to lie upstream of apoptotic cell death. We also detected the regulation of unique as well as shared sets of transcription factors in each line, suggesting that Dpep may initiate a cascade of transcriptional responses that culminate in cancer cell death. Such death thus appears to reflect context-dependent, yet shared, disruption of multiple cellular pathways as well as of individual survival-relevant genes.

Identification of novel molecular subtypes and a signature to predict prognosis and therapeutic response based on cuproptosis-related genes in prostate cancer

Background

Prostate cancer (PCa) is the most common malignant tumor of the male urinary system. Cuproptosis, as a novel regulated cell death, remains unclear in PCa. This study aimed to investigate the role of cuproptosis-related genes (CRGs) in molecular stratification, prognostic prediction, and clinical decision-making in PCa.

Methods

Cuproptosis-related molecular subtypes were identified by consensus clustering analysis. A prognostic signature was constructed with LASSO cox regression analyses with 10-fold cross-validation. It was further validated in the internal validation cohort and eight external validation cohorts. The tumor microenvironment between the two risk groups was compared using the ssGSEA and ESTIMATE algorithms. Finally, qRT-PCR was used to explore the expression and regulation of these model genes at the cellular level. Furthermore, 4D Label-Free LC-MS/MS and RNAseq were used to investigate the changes in CRGs at protein and RNA levels after the knockdown of the key model gene B4GALNT4.

Results

Two cuproptosis-related molecular subtypes with significant differences in prognoses, clinical features, and the immune microenvironment were identified. Immunosuppressive microenvironments were associated with poor prognosis. A prognostic signature comprised of five genes (B4GALNT4, FAM83D, COL1A, CHRM3, and MYBPC1) was constructed. The performance and generalizability of the signature were validated in eight completely independent datasets from multiple centers. Patients in the high-risk group had a poorer prognosis, more immune cell infiltration, more active immune-related functions, higher expression of human leukocyte antigen and immune checkpoint molecules, and higher immune scores. In addition, anti-PDL-1 immunotherapy prediction, somatic mutation, chemotherapy response prediction, and potential drug prediction were also analyzed based on the risk signature. The validation of five model genes' expression and regulation in qPCR was consistent with the results of bioinformatics analysis. Transcriptomics and proteomics analyses revealed that the key model gene B4GALNT4 might regulate CRGs through protein modification after transcription.

Conclusion

The cuproptosis-related molecular subtypes and the prognostic signature identified in this study could be used to predict the prognosis and contribute to the clinical decision-making of PCa. Furthermore, we identified a potential cuproptosis-related oncogene B4GALNT4 in PCa, which could be used as a target to treat PCa in combination with cuproptosis.

Pan-cancer and single-cell analysis reveals FAM83D expression as a cancer prognostic biomarker

Background: The family with sequence similarity 83 member D (FAM83D) protein is known to play a significant role in many human diseases. However, its role in cancer remains ambiguous. This study aimed to investigate the function of FAM83D in a pan-cancer analysis, with a special focus on breast cancer. Methods: Samples were collected from The Cancer Genome Atlas (TCGA) and used for bioinformatic analysis. Datasets from the Gene Expression Omnibus (GEO) and Genotype-Tissue Expression (GTEx) databases were also analyzed for verification. The potential value of FAM83D as a prognostic and diagnostic biomarker was visualized through R software. The "survival" and "GSVA" package were used for univariate, multivariate and pathway enrichment analyseis. We further analyzed the CancerSEA databases and TISIDB websites for single-cell and immune-related profiling. Lastly, we validated those data in vitro using quantitative reverse transcriptase-polymerase chain reaction (RT‒qPCR), cell counting kit-8 (CCK-8), transwell, flow cytometry, and tumorigenicity assays in a murine cell line model. Results: The expression of FAM83D in tumor samples was significantly higher than in normal tissues for most cancer types in the datasets. We confirmed this finding using RT‒qPCR in a breast cancer cell line. Analysis of multiple datasets suggests that overall survival (OS) was extremely poor for breast cancer patients with high FAM83D expression. The CCK-8 assay demonstrated that MCF-7 cell proliferation was inhibited after genetic silencing of FAM83D. Transwell assay showed that knockdown of FAM83D significantly inhibited the invasion and migration ability of MCF-7 cells compared to the control. The results of flow cytometry showed that silencing FAM83D could block the G1 phase of MCF-7 cells compared with negative groups. The tumorigenicity assay in nude mice indicated that the tumorigenic ability to silence FAM83D decreased compared. Conclusion: Results suggest that FAM83D expression can serve as a valuable biomarker and core gene across cancer types. Furthermore, FAM83D expression is significantly associated with MCF-7 cell proliferation and thus may be a prospective prognostic biomarker especially for breast cancer.

Pan-cancer analysis of the FAM83 family and its association with prognosis and tumor microenvironment

Family with sequence similarity 83 (FAM83) is a newly identified family of oncogenes whose members play important roles in signaling and cancer progression. However, a thorough understanding of the FAM83 family in tumors is still lacking. Here, we performed a comprehensive analysis of the expression levels of the FAM83 family across cancers and patient prognoses using bioinformatics methods. We found that the expression levels of FAM83 family genes were upregulated in most tumors, and importantly, high expression levels of FAM83 family genes were related to poor prognosis in most tumors. In addition, we analyzed the relationship of FAM83 family genes with immune subtypes and the tumor microenvironment (TME). The results showed that FAM83 family genes were significantly associated with immune infiltrative subtypes and to varying degrees with the level of stromal cell infiltration and tumor stem cells. Finally, our study also showed the relationship between FAM83 family genes and drug sensitivity. Therefore, this pan-cancer analysis demonstrates the critical role of FAM83 family genes in tumor development and provides new clues for therapeutic strategies for cancer.

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.

Suppression of FAM83D Inhibits Glioma Proliferation, Invasion and Migration by Regulating the AKT/mTOR Signaling Pathway

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FAM83D is upregulated in the glioma cells and tissues.

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Silencing FAM83D inhibits the proliferation, invasion and migration of glioma cells.

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Silencing FAM83D inhibits the activity of AKT/mTOR signaling pathway.

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FAM83D inhibition limits the in vivo growth of glioma cells.

Objective

To explore the mechanism by which the family with sequence similarity 83, member D (FAM83D)-mediated AKT/mTOR signaling pathway activation affects the proliferation and metastasis of glioma cells.

Methods

FAM83D protein expression in glioma cells and tissues was detected by western blotting. Glioma U87 and U251 cells were selected and divided into the Mock, siNC, siFAM83D, FAM83D, MK2206 and FAM83D + MK2206 groups. Cell proliferation was assessed by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) and clone formation assays, while invasion and migration were evaluated by Transwell assays and wound healing tests. The protein expression of members of the AKT/mTOR pathway was determined via western blotting. Xenograft models were also established in nude mice to observe the in vivo effect of FAM83D on the growth of glioma.

Results

FAM83D was upregulated in glioma patients, especially in those with Stage III-IV. In addition, cells treated with siFAM83D had significant downregulation of p-AKT/AKT and p-mTOR/mTOR, with decreased proliferation and colony numbers, as well as decreased invasion and migration compared to the Mock group. However, FAM83D overexpression could activate the Akt/mTOR pathway and promote the proliferation, invasion and migration of glioma cells. Moreover, treatment with MK2206, an inhibitor of AKT, reversed the promoting effect of FAM83D on the growth of glioma cells. The in vivo experiments demonstrated that silencing FAM83D could inhibit the in vivo growth of glioma cells

Conclusion

FAM83D was upregulated in glioma and silencing FAM83D suppressed the proliferation, invasion and migration of glioma cells via inhibition of the AKT/mTOR pathway.

Comprehensive Analysis and Identification of Prognostic Biomarkers and Therapeutic Targets Among FAM83 Family Members for Gastric Cancer

Background: Gastric cancer (GC) is one of the most common and poor prognosis malignancy in the world. The Family with sequence similarity 83 (FAM83) comprises of eight members of A–H. Accumulating evidence confirmed important roles for FAM83 family in tumorigenesis and progression. However, the prognostic values of FAM83 family in GC still have not been clarified.

Methods: ONCOMINE, UALCAN, GEPIA, THE HUMAN PROTEIN ATLAS, Kaplan–Meier Plotter, cBioPortal, DAVID, STRING and TIMER databases and R software were adopted in this study.

Results: In this study, we demonstrated that the mRNA levels of FAM83 B/C/D/H were significantly up-regulated in stomach adenocarcinoma (STAD), but the protein level of FAM83G/H were remarkable lowly in STAD. Next, FAM83C/D/G/H were significantly associated with tumor stages in STAD patients. Then, the mutation rate of FAM83 family members in STAD patients was 46%, and the highest mutation rate was FAM83H (23%). Furthermore, the functions of FAM83 family and their 259 co-expression genes were primarily related to Shigellosis, RNA degradation and Ribosome biogenesis in eukaryotes pathway. Besides, we have established the prognostic model of FAM83 family in STAD, including the prognostic model of STAD patients (FAM83C/D/G), STAD with lymph node metastasis (FAM83C/D/G/H) and STAD with ERBB2 high expression (FAM83G/H). FAM83C/D high expression with a poor prognosis, while FAM83G/H high expression with a favorable prognosis of STAD. Additionally, we found that the expression of FAM83C/D/G/H were significantly correlated with the infiltration of six types of immune cells [B cells, CD8⁺T cells, CD4⁺T cells, macrophages and Myeloid dendritic cells (DC)], whereas CD4⁺T cells and Macrophage cells have higher risk scores (HR > 1) when FAM83C lowly expression and FAM83D highly expression. The risk score of NK cells was significantly reduced when FAM83G lowly expression and FAM83H highly expression (HR < 1).

Conclusion: These findings suggested that FAM83C/D/G/H might play key roles in STAD tumorigenesis and progression, and FAM83C/D might be risk factors but FAM83G/H might be favorable prognostic factors for STAD patients. In addition, CD4⁺T cells and Macrophage cells may be the promoters of FAM83D in progression of STAD, while NK cells may promote the protective effect of FAM83H on STAD patients.

Identification of Prognostic Biomarkers Among FAM83 Family Genes in Human Ovarian Cancer Through Bioinformatic Analysis and Experimental Verification

Purpose

Family with sequence similarity 83 (FAM83) is a newly discovered oncogene family, and the members of which can affect the prognosis of patients with malignant tumors via various mechanisms. However, the functions and molecular mechanisms of FAM83 genes in ovarian cancer (OC) have not yet been investigated. This study aimed to explore the clinical significance and prognostic value of FAM83 genes in OC.

Materials and Methods

We used a series of bioinformatics databases (Oncomine, GEPIA, cBioPortal, Kaplan–Meier plotter, DAVID and TIMER) to investigate the expression status, prognostic value, genetic alteration and biological function of all eight FAM83 genes in OC. In addition, a tissue microarray cohort (TMA) comprising 99 ovarian tumor tissues and 19 normal ovarian tissues was used to validate the protein expression and clinicopathological significance of FAM83H.

Results

Several datasets demonstrated the mRNA levels of FAM83A/D/E/F/H were significantly higher in OC compared with that in normal tissue. Moreover, the upregulation of FAM83D/H has been mutually confirmed in the Oncomine and GEPIA datasets. Kaplan–Meier survival analysis indicated that the FAM83D/H upregulation could predict poor prognosis of OC patients who had shorter overall survival (OS) and progression-free survival (PFS). In addition, cBioportal analysis indicated that the genetic alterations of FAM83 genes might affect the survival outcomes of patients with OC. Furthermore, KEGG analysis suggested that FAM83D/H are involved in the progression of OC through the cell cycle signaling pathway, and they had significant co-expression relationship with cell cycle-related genes. Finally, immunohistochemistry analysis confirmed the high expression of FAM83H protein in OC tissue, suggesting that its expression is positively correlated with the FIGO stage and pathological subtype of OC.

Conclusion

This study elucidated the expression status and prognostic value of FAM83 genes in OC and identified that FAM83D/H might be potential targets for the prognostic monitoring and targeted therapy of OC.

NOVA1-Mediated SORBS2 Isoform Promotes Colorectal Cancer Migration by Activating the Notch Pathway

Background: Gene expression and alternative splicing (AS) can promote cancer development via complex mechanisms. We aimed to identify and verify the hub AS events and splicing factors associated with the progression of colorectal cancer (CRC).

Methods: RNA-Seq data, clinical data, and AS events of 590 CRC samples were obtained from the TCGA and TCGASpliceSeq databases. Cox univariable and multivariable analyses, KEGG, and GO pathway analyses were performed to identify hub AS events and splicing factor/spliceosome genes, which were further validated in five CRCs.

Results: In this study, we first compared differentially expressed genes and gene AS events between normal and tumor tissues. Differentially expressed genes were different from genes with differentially expressed AS events. Prognostic analysis and co-expression network analysis of gene expression and gene AS events were conducted to screen five hub gene AS events involved in CRC progression: EPB41L2, CELF2, TMEM130, VCL, and SORBS2. Using qRT-PCR, we also verified that the gene AS events SORBS2 were downregulated in tumor tissue, and gene AS events EPB41L2, CELF2, TMEM130, and VCL were upregulated in tumor tissue. The genes whose mRNA levels were significantly related to the five hub gene AS events were significantly enriched in the GO term of cell division and Notch signaling pathway. Further coexpression of gene AS events and alternative splicing factor genes revealed NOVA1 as a crucial factor regulating the hub gene AS event expression in CRC. Through in vitro experiments, we found that NOVA1 inhibited gene AS event SORBS2, which induced the migration of CRC cells via the Notch pathway.

Conclusion: Integrated analysis of gene expression and gene AS events and further experiments revealed that NOVA1-mediated SORBS2 promoted the migration of CRC, indicating its potential as a therapeutic target.

The FBXW7-NOTCH interactome: A ubiquitin proteasomal system-induced crosstalk modulating oncogenic transformation in human tissues

BACKGROUND

Ubiquitin ligases or E3 ligases are well programmed to regulate molecular interactions that operate at a post-translational level. Skp, Cullin, F-box containing complex (or SCF complex) is a multidomain E3 ligase known to mediate the degradation of a wide range of proteins through the proteasomal pathway. The three-dimensional domain architecture of SCF family proteins suggests that it operates through a novel and adaptable "super-enzymatic" process that might respond to targeted therapeutic modalities in cancer.

RECENT FINDINGS

Several F-box containing proteins have been characterized either as tumor suppressors (FBXW8, FBXL3, FBXW8, FBXL3, FBXO1, FBXO4, and FBXO18) or as oncogenes (FBXO5, FBXO9, and SKP2). Besides, F-box members like βTrcP1 and βTrcP2, the ones with context-dependent functionality, have also been studied and reported. FBXW7 is a well-studied F-box protein and is a tumor suppressor. FBXW7 regulates the activity of a range of substrates, such as c-Myc, cyclin E, mTOR, c-Jun, NOTCH, myeloid cell leukemia sequence-1 (MCL1), AURKA, NOTCH through the well-known ubiquitin-proteasome system (UPS)-mediated degradation pathway. NOTCH signaling is a primitive pathway that plays a crucial role in maintaining normal tissue homeostasis. FBXW7 regulates NOTCH protein activity by controlling its half-life, thereby maintaining optimum protein levels in tissue. However, aberrations in the FBXW7 or NOTCH expression levels can lead to poor prognosis and detrimental outcomes in patients. Therefore, the FBXW7-NOTCH axis has been a subject of intense study and research over the years, especially around the interactome's role in driving cancer development and progression. Several studies have reported the effect of FBXW7 and NOTCH mutations on normal tissue behavior. The current review attempts to critically analyze these mutations prognostic value in a wide range of tumors. Furthermore, the review summarizes the recent findings pertaining to the FBXW7 and NOTCH interactome and its involvement in phosphorylation-related events, cell cycle, proliferation, apoptosis, and metastasis.

CONCLUSION

The review concludes by positioning FBXW7 as an effective diagnostic marker in tumors and by listing out recent advancements made in cancer therapeutics in identifying protocols targeting the FBXW7-NOTCH aberrations in tumors.

Fam83D promotes tumorigenesis and gemcitabine resistance of pancreatic adenocarcinoma through the Wnt/β-catenin pathway

BACKGROUND

Elevated expression of family with sequence similarity 83 member D (Fam83D) has been found in various cancers; however, its role in pancreatic adenocarcinoma (PDAC) remains unclear. The current study was designed to elucidate the roles of Fam83D in pancreatic cancer.

METHOD

The level of Fam83D was detected in PDAC tissues and adjacent no-tumorous tissues. Effects of Fam83D on proliferation, glycolysis and gemcitabine (GEM) sensitivity of pancreatic cancer cells were examined.

RESULTS

Fam83D was overexpressed in PDAC and associated with clinical stage, metastatic status and survival rates of PDAC patients. Function study showed that Fam83D knockdown (KD) caused inhibited proliferation, suppressed mitochondrial respiration capacity, reduced aerobic glycolysis, and down-regulation of nuclear β-catenin, proto-oncogene C-Myc, and lactate dehydrogenase A (LDHA). Fam83D KD enhanced the sensitivity of PDAC cells to GEM in vitro and in vivo. On the contrary, Fam83D overexpression displayed reverse effects on PDAC cells. Moreover, the Wnt/β-catenin inhibitor abolished the effects of Fam83D overexpression in PDAC cells.

CONCLUSIONS

the current data suggest that enhanced Fam83D expression contributes to PDAC progression and the development of chemoresistance through the Wnt/β-catenin signaling.

Comprehensive serum proteomic analysis in early endometrial cancer

OBJECTIVE

Endometrial cancer is the most common gynecologic cancer and yet much is still unknown about this disease. Our goal was to identify unique biomarkers of disease by performing a comprehensive proteomic analysis of early stage, low-grade endometrial cancer through analysis of serum collected from patients pre- and post-definitive surgery.

METHODS

We used mass spectrometry (MS)-based proteomics to identify serum proteins from these patients. Serum samples from women undergoing hysterectomy with bilateral salpingo-oophorectomy for benign reasons served as control samples for the correlative studies. We then correlated our findings with The Cancer Genome Atlas (TCGA) database for additional confirmation.

RESULTS

The Ingenuity Pathway Analysis of proteins that were differentially expressed in endometrial cancer showed increased cell survival and decreased organismal death, the most common hallmarks of cancer. We identified over expression of FAM83D (family with sequence similarity 83, member D) in the serum of patients with early stage low-grade endometrial cancer and verified the same in the endometrial cancer cell lines and patient tumors. We also confirmed our hypothesis that FAM83D may serve as a biomarker for endometrial cancer in a cohort of patients with endometrial cancer from The Cancer Genome Atlas (TCGA) project.

CONCLUSION

Comprehensive proteomic analysis is a feasible strategy for potential biomarker identification. Using this technique, FAM83D was identified as a candidate biomarker in early endometrial cancer in our patient samples and was not present in benign control samples. FAM83D has been associated with poor clinical outcomes in several human malignancies.

SIGNIFICANCE

Our manuscript describes an alternative approach to comprehensive protein analysis in a model pre and post tumor removal for a sample of patients with early endometrial cancer. The model is innovative and the findings of over expression FAM83D in this population of early cancer may be useful in the study of a disease where there are few biomarkers or targetable therapies.

Systematic Analysis of Expression Profiles and Prognostic Significance for FAM83 Family in Non-small-Cell Lung Cancer

Background

Lung cancer remains a common malignancy and the leading cause of cancer-related deaths in the world. Although dramatic progress made in multimodal therapies, it still has a poor prognosis. The Family with sequence similarity 83 (FAM83) of poorly characterized proteins are defined by the presence of the conserved DUF1669 domain of unknown function at their N-termini, most of which significantly elevated levels of expression in multiple cancers. However, the expression and prognostic values of different FAM83 family in lung cancer, especially in non-small-cell lung cancer (NSCLC), have not been clarified.

Methods

ONCOMINE, UALCAN, GEPIA, Kaplan–Meier Plotter, cBioPortal, and STRING databases were utilized in this study.

Results

The transcriptional levels of FAM83A/B/C/D/F/G/H were up-regulated in patients with NSCLC. A noticeable correlation was found between the over-expressions of FAM83A/B/D/F/H and clinical cancer stages in NSCLC patients. Besides, higher mRNA expressions of FAM83A/B/C/D/F/H were discovered to be expressively associated with overall survival (OS) in lung cancer patients, furthermore, FAM83A, FAM83C, and FAM83H in OS group achieved 0.9475/1, 0.971897/1, and 0.9454545/0.8974359 specificity/sensitivity in distinguishing short survivors from long survivors, respectively. Moreover, a high mutation rate of FAM83 family (51%) was also observed in lung adenocarcinoma (LUAD) patients, and genetic alteration in the FAM83 family was associated with shorter OS and disease-free survival (DFS) in LUAD patients.

Conclusion

Our results indicated that FAM83A/H might play important roles in NSCLC tumorigenesis and might be risk factor for the survival of NSCLC patients.

Identification of NUF2 and FAM83D as potential biomarkers in triple-negative breast cancer

Background

Breast cancer is a heterogeneous disease. Compared with other subtypes of breast cancer, triple-negative breast cancer (TNBC) is easy to metastasize and has a short survival time, less choice of treatment options. Here, we aimed to identify the potential biomarkers to TNBC diagnosis and prognosis.

Material/Methods

Three independent data sets (GSE45827, GSE38959, GSE65194) were downloaded from the Gene Expression Omnibus (GEO). The R software packages were used to integrate the gene profiles and identify differentially expressed genes (DEGs). A variety of bioinformatics tools were used to explore the hub genes, including the DAVID database, STRING database and Cytoscape software. Reverse transcription quantitative PCR (RT-qPCR) was used to verify the hub genes in 14 pairs of TNBC paired tissues.

Results

In this study, we screened out 161 DEGs between 222 non-TNBC and 126 TNBC samples, of which 105 genes were up-regulated and 56 were down-regulated. These DEGs were enriched for 27 GO terms and two pathways. GO analysis enriched mainly in “cell division”, “chromosome, centromeric region” and “microtubule motor activity”. KEGG pathway analysis enriched mostly in “Cell cycle” and “Oocyte meiosis”. PPI network was constructed and then 10 top hub genes were screened. According to the analysis results of the Kaplan-Meier survival curve, the expression levels of only NUF2, FAM83D and CENPH were associated with the recurrence-free survival in TNBC samples (P < 0.05). RT-qPCR confirmed that the expression levels of NUF2 and FAM83D in TNBC tissues were indeed up-regulated significantly.

Conclusions

The comprehensive analysis showed that NUF2 and FAM83D could be used as potential biomarkers for diagnosis and prognosis of TNBC.

Using mRNAsi to identify prognostic-related genes in endometrial carcinoma based on WGCNA

AIMS

Cancer Stem Cells (CSCs) refers to heterogeneous tumor cells retaining the abilities of self-renewal and differentiation. This study used mRNAsi, which is an index to describe the similarity between tumor cells and CSCs, to define genes involved in endometrial carcinoma.

MATERIALS AND METHODS

The mRNA expression profiles of 552 tumor samples and 23 non-tumor samples were calculated for differentially expressed genes. WGCNA was utilized to construct gene co-expression networks and classify screened genes into different modules. Univariate and multivariate Cox regression models were performed to identify and construct the prognostic model. Time-dependent receiver operating characteristic (ROC), Kaplan-Meier curve, multivariate Cox regression analysis, and nomogram were used to assess the prognostic capacity of the six-gene signature. The screened genes were further validated by GEO (GSE17025) and qRT-PCR in EC tissues.

KEY FINDINGS

2573 upregulated and 1890 downregulated genes were identified. A total of 35 genes in the turquoise module were identified as key genes. With multivariate analysis, six genes (DEPDC1, FAM83D, NCAPH, SPC25, TPX2, and TTK) up-regulated in endometrial carcinoma were identified, and their higher expression was associated with a higher stage/age/grade. Moreover, ROC and Kaplan-Meier plots indicated these genes had a high prognostic value for EC. A nomogram was constructed for clinical use. In addition, we explored the pathogenesis involving six genes. The results showed that these genes may become pathogenic as their copy numbers changes and methylation level reduces. Finally, GSEA revealed these genes had a close association with cell cycle, etc. SIGNIFICANCE: These findings may provide new insights into the treatment of diseases.

Knockdown of FAM83D Enhances Radiosensitivity in Coordination with Irradiation by Inhibiting EMT via the Akt/GSK-3β/Snail Signaling Pathway in Human Esophageal Cancer Cells

Purpose

To explore the effects of FAM83D on the proliferation, invasion and radiosensitivity of human esophageal cancer cells and to elucidate the mechanism involved in the regulation of the growth and metastasis of esophageal cancer cells.

Methods and Materials

This study included sixty-nine patients with esophageal cancer. The expression levels of FAM83D in the esophageal cancer tissues and paracarcinoma tissues of the sixty-nine patients were measured. We also examined FAM83D expression in five cell lines. We analyzed the effects of FAM83D on the proliferation, invasion and radiosensitivity of human esophageal cancer cells via MTS, Transwell, and colony formation assays. The effect of FAM83D knockdown on cell apoptosis was assayed by flow cytometry. In addition, we also examined changes in the expression of metastasis-related molecules at the protein and mRNA levels by qRT-PCR and Western blotting after silencing FAM83D expression, and we detected the expression of PI3K/Akt signaling-related proteins by Western blotting.

Results

The results demonstrated that the expression of FAM83D was obviously higher in esophageal cancer tissues and cell lines than that in human adjacent normal tissues and normal esophageal epithelial cell lines. FAM83D overexpression was positively associated with tumor size, tumor-node-metastasis (TNM) stage, T classification, N classification, distant metastasis and relapse and was negatively associated with patient survival rates. FAM83D shRNA transfection suppressed its expression. Compared to that in the control group, the proliferation of tumor cells in the FAM83D shRNA group was hindered after exposure to radiation in vitro and in vivo; in addition, FAM83D knockdown inhibited cell invasion, induced apoptosis and regulated apoptosis-related protein expression. Moreover, the radiosensitivity of esophageal cancer cells was increased after depletion of FAM83D. In addition, FAM83D silencing was associated with the reversion of EMT, as reflected by an increase in the epithelial marker E-cadherin and a decrease in the mesenchymal markers N-cadherin and vimentin. Further study showed that FAM83D depletion suppressed the signaling pathway involving p-Akt, p-GSK-3β and Snail.

Conclusion

The results reveal that FAM83D may be a potential therapeutic target for esophageal squamous cell carcinoma (ESCC) and that lower expression of FAM83D in coordination with irradiation promotes the radiosensitization of ESCC by inducing EMT through the Akt/GSK-3β/Snail signaling pathway.

Cell proliferation is induced in renal cell carcinoma through miR-92a-3p upregulation by targeting FBXW7

Renal cell carcinoma (RCC) is the most common type of kidney cancer whose incidence has gradually increased worldwide. MicroRNAs (miRNAs) represent a type of short endogenous non-coding RNA containing approximately 22 nucleotides, which are capable of regulating mRNAs at the post-transcriptional level in human cells. miRNAs have been demonstrated to mediate gene expression by influencing important regulatory genes. Accumulating evidence indicates that certain miRNAs are involved in RCC development. The present study investigated the underlying mechanism and functional role of miR-92a-3p in RCC cells using reverse transcription-quantitative polymerase chain reaction, western blotting, 3′ UTR luciferase assay, cell proliferation assay and soft agar assay. The results demonstrated that miR-92a-3p expression level is significantly upregulated in RCC tissues and cell lines; however, F-box and WD repeat domain containing 7 (FBXW7) expression level was significantly downregulated in RCC tissues and cell lines. Subsequently, whether FBXW7 could be considered as a direct target of miR-92a-3p in RCC cells was investigated. The results demonstrated that miR-92a-3p overexpression significantly promoted RCC cell proliferation and colony formation. Conversely, miR-92a-3p downregulation significantly inhibited RCC cell proliferation and colony formation. In addition, FBXW7 knockdown significantly enhanced RCC cell proliferation and colony formation. Conversely, FBXW7 overexpression significantly inhibited RCC cell proliferation and colony formation. Collectively, these results demonstrated that miR-92a-3p/FBXW7 pathway may represent a novel strategy and therapeutic target for RCC.

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 promotes epithelial-mesenchymal transition, invasion and cisplatin resistance through regulating the AKT/mTOR pathway in non-small-cell lung cancer

PURPOSE

FAM83D has been proposed to act as an oncoprotein in several types of human cancer. Its role and mode of action in human non-small cell lung cancer (NSCLC) metastasis and its impact on chemotherapy are as yet, however, poorly understood.

METHODS

FAM83D expression was measured in NSCLC cells and normal lung epithelial cells, as well as in primary NSCLC tissues and corresponding adjacent non-cancerous tissues, using qRT-PCR, Western blotting and immunohistochemistry. FAM83D was stably overexpressed in BEAS2B cells or silenced in A549 and H1299 cells using retroviral or lentiviral vectors. The growth capacity of NSCLC cells was evaluated using MTT and colony formation assays. Epithelial-mesenchymal transition (EMT) was assessed using Western blotting and immunofluorescence. NSCLC cell invasive capacities were assessed using scratch wound healing and Boyden chamber assays. NSCLC cell viability in response to cisplatin treatment was assessed using MTT assays in vitro and a xenograft model in vivo.

RESULTS

We found that FAM83D expression levels were significantly elevated in NSCLC cells and tissues, and positively correlated with tumor progression and a poor prognosis. Exogenous FAM83D overexpression promoted, while FAM83D silencing inhibited NSCLC cell proliferation, EMT and invasion. FAM83D silencing also reduced cisplatin resistance. Concordantly, we found that NSCLC patients with a low FAM83D expression benefited most from chemotherapy. Mechanistically, we found that FAM83D activated the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway. Pharmacological treatment with either AKT or mTOR inhibitors reverted FAM83D-induced tumorigenic phenotypes.

CONCLUSIONS

Our results suggest a role of FAM83D in NSCLC development. In addition, our results indicate that NSCLC patients exhibiting FAM83D overexpression are likely to benefit from AKT and/or mTOR inhibitor treatment.

Ubiquitin-Regulated Cell Proliferation and Cancer

Ubiquitin ligases (E3) play a crucial role in the regulation of different cellular processes such as proliferation and differentiation via recognition, interaction, and ubiquitination of key cellular proteins in a spatial and temporal regulated manner. The type of ubiquitin chain formed determines the fate of the substrates. The ubiquitinated substrates can be degraded by the proteasome, display altered subcellular localization, or can suffer modifications on their interaction with functional protein complexes. Deregulation of E3 activities is frequently found in various human pathologies, including cancer. The illegitimated or accelerated degradation of oncosuppressive proteins or, inversely, the abnormally high accumulation of oncoproteins, contributes to cell proliferation and transformation. Anomalies in protein abundance may be related to mutations that alter the direct or indirect recognition of proteins by the E3 enzymes or alterations in the level of expression or activity of ubiquitin ligases. Through a few examples, we illustrate here the complexity and diversity of the molecular mechanisms related to protein ubiquitination involved in cell cycle regulation. We will discuss the role of ubiquitin-dependent degradation mediated by the proteasome, the role of non-proteolytic ubiquitination during cell cycle progression, and the consequences of this deregulation on cellular transformation. Finally, we will highlight the novel opportunities that arise from these studies for therapeutic intervention.

Study of the aqueous extract of Aloe vera and its two active components on the Wnt/β-catenin and Notch signaling pathways in colorectal cancer cells

ETHNOPHARMACOLOGICAL RELEVANCE

Aloe vera (L.) Burm. f. (Aloe vera) is a common Traditional Chinese Medicine (TCM) recorded in Pharmacopoeia of the People's Republic of China (version 2015). It has been traditionally used for treatment of constipation. Aloe vera requires much attention for its safety evaluation because several studies have reported the association between oral consumption of Aloe vera and the development of colorectal cancer (CRC). However the material basis and molecular mechanism are.still less well elucidated. Although Wnt/β-catenin and Notch signaling pathway have been known to be closely related to the initiation and development of CRC, the impacts of Aloe vera on these cancerous pathways have not been completely determined yet.

AIM OF THIS STUDY

Hence, this study aimed to study the impacts of Aloe vera on the Wnt/β-catenin and Notch signaling pathway, as well as proliferation of CRC cells.

MATERIALS AND METHODS

Firstly, the effects of Aloe vera aqueous extract and its two active components (aloin and aloesin) on the Wnt/β-catenin and Notch signaling pathway were studied by luciferase reporter, RT-qPCR, western blotting and immunofluorescence assays, respectively. Furthermore, RNA sequencing analysis (RNA-seq) was then performed to verify their regulatory activities on the Wnt-related and Notch-related genes expression. Finally, their impacts on RKO cell proliferation and cell cycle phase were also evaluated via MTT assay and cell cycle analysis.

RESULTS

Our results indicate that the aqueous extract of Aloe vera and its active component aloin activated the Wnt/β-catenin pathway and inhibited the Notch signaling pathway only in the presence of Wnt3a. While aloesin was characterized to directly activate the Wnt/β-catenin pathway and inhibit the Notch pathway independent of Wnt3a. Within 24h, the Aloe vera extract and its two components were failed to affect the proliferation or cell cycle phase of RKO cells. Nevertheless, in the presence of Wnt3a, the aqueous extract of Aloe vera with the concentration of 33.3 μg/ml start to promote the cell proliferation of RKO cells after 48h incubation.

CONCLUSION

In conclusion, this study showed that Aloe vera extract and its active component aloin activated the Wnt/β-catenin pathway and inhibited the Notch pathway in the presence of Wnt3a. While another active component, aloesin, activated the Wnt/β-catenin pathway and inhibited the Notch signaling pathway independent of Wnt3a. Given that Wnt/β-catenin and Notch pathway are closely associated with the progression of CRC, these findings would be helpful to better understand the colonic carcinogenicity of Aloe vera.

Mutation profiling of cancer drivers in Brazilian colorectal cancer

The molecular basis of colorectal cancer (CRC) can guide patient prognosis and therapy. In Brazil, knowledge on the CRC mutation landscape is limited. Here, we investigated the mutation profile of 150 cancer-related genes by next-generation sequencing and associated with microsatellite instability (MSI) and genetic ancestry in a series of 91 Brazilian CRC patients. Driver mutations were found in the APC (71.4%), TP53 (56.0%), KRAS (52.7%), PIK3CA (15.4%) and FBXW7 (10.9%) genes. Overall, genes in the MAPK/ERK, PIK3/AKT, NOTCH and receptor tyrosine kinase signaling pathways were mutated in 68.0%, 23.1%, 16.5%, and 15.3% of patients, respectively. MSI was found in 13.3% of tumors, most of which were proximal (52.4%, P< 0.001) and had a high mutation burden. European genetic ancestry was predominant (median of 83.1%), followed by Native American (4.1%), Asian (3.4%) and African (3.2%). NF1 and BRAF mutations were associated with African ancestry, while TP53 and PIK3CA mutations were inversely correlated with Native American ancestry. Our study suggests that Brazilian CRC patients exhibit a mutation profile similar to other populations and identify the most frequently mutated genes, which could be useful in future target therapies and molecular cancer screening strategies.

Upregulation of family with sequence similarity 83 member D expression enhances cell proliferation and motility via activation of Wnt/β-catenin signaling and predicts poor prognosis in gastric cancer

Background/aims

Gastric cancer (GC) is the third most common cause of cancer-related death worldwide. The molecular mechanisms underlying the progression of gastric cancer are still not fully elucidated. In this study, we focused on exploring the role of family with sequence similarity 83, member D (FAM83D) in gastric cancer progression.

Methods

The expression of FAM83D in GC tissues was detected by immunohistochemistry (IHC) staining. FAM83D knockdown or overexpression were constructed in AGS and SGC-7901 cells with two distinct siRNA duplexes and lentivirus infection, respectively, to explore the role of FAM83D in gastric cancer progression. Nude mouse xenograft assay was used to further explore the role of FAM83D in tumorigenesis in vivo.

Results

We found that FAM83D mRNA and protein levels were higher in human GC tumor tissues and in GC cell lines, compared with the adjacent normal tissues and non-malignant gastric epithelial cell lines, respectively, and that higher FAM83D expression was correlated with worse overall survival (p<0.0001) and disease-free survival (p<0.0001) in GC patients. Additionally, our results showed that FAM83D overexpression significantly enhanced the proliferation, clonogenicity, and motility of GC cells, whereas FAM83D depletion caused a dramatic increase in the number of cells arrested at the G1 phase of the cell cycle. Consistent with these findings from in vitro experiment, our data also indicated that FAM83D knockdown significantly repressed GC tumor growth in vivo. Furthermore, we demonstrated that FAM83D depletion was associated with reduced Wnt/β-catenin signaling.

Conclusions

This study suggested that FAM83D overexpression enhanced the proliferation, clonogenicity, and motility of GC cells by activating Wnt/β-catenin signaling, and FAM83D may be a promising diagnostic and therapeutic target for human GC.

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.

CLDN8 promotes colorectal cancer cell proliferation, migration, and invasion by activating MAPK/ERK signaling

Background

Claudin 8 (CLDN8), an integral membrane protein that constitutes tight junctions in cell membranes, was recently implicated in tumor progression. However, its roles in colorectal cancer (CRC) progression and metastasis remain unknown.

Methods

In this study, we examined the effect of CLDN8 on the progression of CRC, including cell proliferation, migration, and invasion, and determines its underlying molecular mechanism using in vitro CRC cell lines and in vivo mouse xenograft models.

Results

We found that CLDN8 expression in human CRC tissues was significantly higher than that in adjacent normal tissues. The knockdown of CLDN8 markedly suppressed the proliferation, migration, and invasion of SW480 and HT-29 CRC cells, whereas the overexpression of CLDN8 notably promoted tumor progression in SW480 and HT-29 CRC cells. Mechanistic studies revealed that CLDN8 upregulated p-ERK (p-PKB/AKT) and MMP9 in CRC cells. Notably, the MAPK/ERK inhibitor PD98095 dramatically attenuated the effects of CLDN8 on p-ERK and MMP9. Moreover, PD98095 remarkably blocked the tumor-promoting activity of CLDN8. The knockdown of CLDN8 also inhibited the in vivo tumor growth in a nude mouse xenograft model. Collectively, CLDN8 promoted CRC cell proliferation, migration, and invasion, at least in part, by activating the MAPK/ERK signaling pathway.

Conclusion

These findings suggest that CLDN8 exhibits an oncogenic effect in human CRC progression.

FBXW7 in Cancer: What Has Been Unraveled Thus Far?

: The FBXW7 (F-box with 7 tandem WD40) protein encoded by the gene FBXW7 is one of the crucial components of ubiquitin ligase called Skp1-Cullin1-F-box (SCF) complex that aids in the degradation of many oncoproteins via the ubiquitin-proteasome system (UPS) thus regulating cellular growth. FBXW7 is considered as a potent tumor suppressor as most of its target substrates can function as potential growth promoters, including c-Myc, Notch, cyclin E, c-JUN, and KLF5. Its regulators include p53, C/EBP-δ, Numb, microRNAs, Pin 1, Hes-5, BMI1, Ebp2. Mounting evidence has indicated the involvement of aberrant expression of FBXW7 for tumorigenesis. Moreover, numerous studies have also shown its role in cancer cell chemosensitization, thereby demonstrating the importance of FBXW7 in the development of curative cancer therapy. This comprehensive review emphasizes on the targets, functions, regulators and expression of FBXW7 in different cancers and its involvement in sensitizing cancer cells to chemotherapeutic drugs.

Overview of the oncogenic signaling pathways in colorectal cancer: Mechanistic insights

Colorectal cancer is a multifaceted disease which is therapeutically challenging. Based on insights gleaned from almost a quarter century of research, it is obvious that deregulation of spatio-temporally controlled signaling pathways play instrumental role in development and progression of colorectal cancer. High-throughput technologies have helped to develop a sharper and broader understanding of the wide ranging signal transduction cascades which also contribute to development of drug resistance, loss of apoptosis and, ultimately, of metastasis. In this review, we have set the spotlight on role of JAK/STAT, TGF/SMAD, Notch, WNT/β-Catenin, SHH/GLI and p53 pathways in the development and progression of colorectal cancer. We have also highlighted recent reports on TRAIL-mediated pathways and molecularly distinct voltage-gated sodium channels in colorectal cancer.

STK899704 inhibits stemness of cancer stem cells and migration via the FAK-MEK-ERK pathway in HT29 cells

Colon cancer is one of the most lethal and common malignancies worldwide. STK899704, a novel synthetic agent, has been reported to exhibit anticancer effects towards numerous cancer cells. However, the effect of STK899704 on the biological properties of colon cancer, including cancer cell migration and cancer stem cells (CSCs), remains unknown. Here, we examined the inhibitory effect of STK899704 on cell migration and CSC stemness. In the wound healing assay, STK899704 significantly inhibited the motility of colon cancer cells. Furthermore, STK899704 downregulated the mRNA expression levels of the cell migration mediator focal adhesion kinase (FAK). STK899704 also suppressed mitogen-activated protein kinase kinase and extracellular signal-regulated kinase, which are downstream signaling molecules of FAK. Additionally, STK899704 inhibited stemness gene expression and sphere formation in colon cancer stem cells. These results suggest that STK899704 can be used to treat human colon cancer.

FBXW7: a critical tumor suppressor of human cancers

The ubiquitin-proteasome system (UPS) is involved in multiple aspects of cellular processes, such as cell cycle progression, cellular differentiation, and survival (Davis RJ et al., Cancer Cell 26:455-64, 2014; Skaar JR et al., Nat Rev Drug Discov 13:889-903, 2014; Nakayama KI and Nakayama K, Nat Rev Cancer 6:369-81, 2006). F-box and WD repeat domain containing 7 (FBXW7), also known as Sel10, hCDC4 or hAgo, is a member of the F-box protein family, which functions as the substrate recognition component of the SCF E3 ubiquitin ligase. FBXW7 is a critical tumor suppressor and one of the most commonly deregulated ubiquitin-proteasome system proteins in human cancer. FBXW7 controls proteasome-mediated degradation of oncoproteins such as cyclin E, c-Myc, Mcl-1, mTOR, Jun, Notch and AURKA. Consistent with the tumor suppressor role of FBXW7, it is located at chromosome 4q32, a genomic region deleted in more than 30% of all human cancers (Spruck CH et al., Cancer Res 62:4535-9, 2002). Genetic profiles of human cancers based on high-throughput sequencing have revealed that FBXW7 is frequently mutated in human cancers. In addition to genetic mutations, other mechanisms involving microRNA, long non-coding RNA, and specific oncogenic signaling pathways can inactivate FBXW7 functions in cancer cells. In the following sections, we will discuss the regulation of FBXW7, its role in oncogenesis, and the clinical implications and prognostic value of loss of function of FBXW7 in human cancers.

Long non-coding RNA LINC00261 sensitizes human colon cancer cells to cisplatin therapy

Colon cancer is one of the most common digestive tumors. The present study aimed to explore the functional role, as well as the underlying mechanism of long non-coding RNA LINC00261 in colon cancer. Expression of LINC00261 was analyzed in colon cancer cell lines and human normal cell lines. Acquired resistance cell lines were then built and the acquired resistance efficiency was detected by evaluating cell viability. Thereafter, the effects of LINC00261 overexpression on cisplatin-resistant colon cancer cells were measured, as well as cell apoptosis, viability, migration, and invasion. Subsequently, we investigated the interaction of LINC00261 and β-catenin. The results showed that the LINC00261 gene was down-regulated in colon cancer cell lines and tissues, and in cisplatin-resistant cells. LINC00261 overexpression might relieve cisplatin resistance of colon cancer cells via promoting cell apoptosis, and inhibiting cell viability, migration, and invasion. Moreover, LINC00261 might down-regulate nuclear β-catenin through restraining β-catenin from cytoplasm into nuclei or it could also promote β-catenin degradation and inhibit activation of Wnt pathway. Finally, LINC00261 reduced cisplatin resistance of colon cancer in vivo and enhanced the anti-colon cancer effect of cisplatin through reducing tumor volume and weight.