The facilitating effects of KRT80 on chemoresistance, lipogenesis, and invasion of esophageal cancer.

Keratin 80 (KRT80) is a filament protein that makes up one of the major structural fibers of epithelial cells, and involved in cell differentiation and epithelial barrier integrity. Here, KRT80 mRNA expression was found to be higher in esophageal cancer than normal epithelium by RT-PCR and bioinformatics analysis (p < .05), opposite to KRT80 methylation (p < .05). There was a negative relationship between promoter methylation and expression level of KRT80 gene in esophageal cancer (p < .05). KRT80 mRNA expression was positively correlated with the differentiation, infiltration of immune cells, and poor prognosis of esophageal cancer (p < .05). KRT80 mRNA expression was positively linked to no infiltration of immune cells, the short survival time of esophageal cancers (p < .05). The differential genes of KRT80 mRNA were involved in fat digestion and metabolism, peptidase inhibitor, and intermediate filament, desosome, keratinocyte differentiation, epidermis development, keratinization, ECM regulator, complement cascade, metabolism of vitamins and co-factor (p < .05). KRT-80-related genes were classified into endocytosis, cell adhesion molecule binding, cadherin binding, cell-cell junction, cell leading edge, epidermal cell differentiation and development, T cell differentiation and receptor complex, plasma membrane receptor complex, external side of plasma membrane, metabolism of amino acids and catabolism of small molecules, and so forth (p < .05). KRT80 knockdown suppressed anti-apoptosis, anti-pyroptosis, migration, invasion, chemoresistance, and lipogenesis in esophageal cancer cells (p < .05), while ACC1 and ACLY overexpression reversed the inhibitory effects of KRT80 on lipogenesis and chemoresistance. These findings indicated that up-regulated expression of KRT80 might be involved in esophageal carcinogenesis and subsequent progression, aggravate aggressive phenotypes, and induced chemoresistance by lipid droplet assembly and ACC1- and ACLY-mediated lipogenesis.

Regenerating gene 4 promotes chemoresistance of colorectal cancer by affecting lipid droplet synthesis and assembly.

BACKGROUND: Regenerating gene 4 (REG4) has been proved to be carcinogenic in some cancers, but its manifestation and possible carcinogenic mechanisms in colorectal cancer (CRC) have not yet been elucidated. Our previous study found that the drug resistance of CRC cells may be closely linked to their fat metabolism. AIM: To explore the role of REG4 in CRC and its association with lipid droplet formation and chemoresistance. METHODS: We conducted a meta-analysis and bioinformatics and pathological analyses of REG4 expression in CRC. The effects of REG4 on the phenotypes and related protein expression were also investigated in CRC cells. We detected the impacts of REG4 on the chemoresistance and lipid droplet formation in CRC cells. Finally, we analyzed how REG4 regulated the transcription and proteasomal degradation of lipogenic enzymes in CRC cells. RESULTS: Compared to normal mucosa, REG4 mRNA expression was high in CRC (P < 0.05) but protein expression was low. An inverse correlation existed between lymph node and distant metastases, tumor-node-metastasis staging or short overall survival and REG4 mRNA overexpression (P < 0.05), but vice versa for REG4 protein expression. REG4-related genes included: Chemokine activity; taste receptors; protein-DNA and DNA packing complexes; nucleosomes and chromatin; generation of second messenger molecules; programmed cell death signals; epigenetic regulation and DNA methylation; transcription repression and activation by DNA binding; insulin signaling pathway; sugar metabolism and transfer; and neurotransmitter receptors (P < 0.05). REG4 exposure or overexpression promoted proliferation, antiapoptosis, migration, and invasion of DLD-1 cells in an autocrine or paracrine manner by activating the epidermal growth factor receptor-phosphoinositide 3-kinase-Akt-nuclear factor-κB pathway. REG4 was involved in chemoresistance not through de novo lipogenesis, but lipid droplet assembly. REG4 inhibited the transcription of acetyl-CoA carboxylase 1 (ACC1) and ATP-citrate lyase (ACLY) by disassociating the complex formation of anti-acetyl (AC)-acetyl-histone 3-AC-histone 4-inhibitor of growth protein-5-si histone deacetylase;-sterol-regulatory element binding protein 1 in their promoters and induced proteasomal degradation of ACC1 or ACLY. CONCLUSION: REG4 may be involved in chemoresistance through lipid droplet assembly. REG4 reduces expression of de novo lipid synthesis key enzymes by inhibiting transcription and promoting ubiquitination-mediated proteasomal degradation.

The promoting effects of GPR176 expression on proliferation, chemoresistance, lipogenesis and invasion of oesophageal cancer.

PURPOSE: As a member of the G-protein-coupled receptor 1 family, the G-protein-coupled receptor 176 (GPR176) gene encodes a glycosylated protein made up of 515 amino acids. The current study was performed to evaluate the impact of GPR176 on the clinicopathology and prognosis of oesophageal cancer, as well as uncover its molecular mechanisms. METHODS: Bioinformatics and clinical tissue samples were used to detect the expression and clinicopathological significance of GPR176 in oesophageal cancer. The expression, proliferation, migration and invasion, apoptosis and lipid droplet formation of GPR176 gene in oesophageal cancer were performed as phenotypic readouts. RESULTS: Here, RT-PCR and bioinformatic analyses revealed that GPR176 mRNA expression was significantly higher in oesophageal cancer than in normal mucosa (p < 0.05). GPR176 mRNA expression was associated with low weight and BMI, low T stage, low N and clinicopathological stage, low histological grade and favourable clinical outcome of oesophageal cancer (p < 0.05). The differential genes of GPR176 mRNA were involved in protein digestion and absorption, extracellular matrix constituent, endoplasmic reticulum lumen, among others (p < 0.05). GPR176-related genes were classified as being involved in oxidoreductase activity, actin and myosin complexes, lipid localisation and transport, among others (p < 0.05). GPR176 knockdown suppressed proliferation, anti-apoptotic and anti-pyroptotic properties, migration, invasion, chemoresistance and lipid droplet formation in oesophageal cancer cells (p < 0.05), while ACC1 and ACLY overexpression reversed the inhibitory effects of GPR176 silencing on lipid droplet formation and chemoresistance. CONCLUSION: These findings indicated that upregulated expression of GPR176 might be involved in oesophageal carcinogenesis and subsequent progression, aggressiveness, and induced chemoresistance by ACC1- and ACLY-mediated lipogenesis and lipid droplet assembly.

Bioinformatics analysis of the clinicopathological and prognostic significance of BAG3 mRNA in gynecological cancers.

BAG3 is a co-chaperone BAG family protein that plays important roles in protein homeostasis, cell survival, cell motility, and tumour metastasis. This study aimed to clarify the clinicopathological and prognostic implications of BAG3 mRNA expression in tumours. We performed bioinformatics analysis on BAG3 mRNA expression using TCGA, XIANTAO, UALCAN, and Kaplan-Meier plotter databases. BAG3 mRNA expression was downregulated in breast and endometrial cancers and positively correlated with favourable PAM50 subtyping in breast cancer，clinical stage and short overall survival in ovarian cancer and negatively correlated with T stage, clinical stage, and histological grade in cervical and endometrial cancers. The top BAG3-related pathways included ligand-receptor interactions and activity, DNA packaging and nucleosomes, hormonal responses, membrane regions, microdomains and rafts, and endosomes in breast cancer; ligand-receptor interactions, transmembrane transporters and channels, cell adhesion, and keratinisation in cervical cancer; ligand-receptor interactions, anion transmembrane transporters, lipoproteins, keratinisation, cell adhesion, and protein processing in endometrial cancer; metabolism of porphyrin, chlorophyll, pentose, uronic acid, ascorbate, and alternate and cell adhesion in ovarian cancer. BAG3 expression could represent a potential marker for carcinogenesis, histogenesis, aggressive behaviours, and prognosis in gynecological cancers.IMPACT STATEMENTWhat is already known on this subject? BAG3 regulates cell activity, autophagy, and resistance to apoptosis through multiple domains and plays an important role in tumour development. BAG3 positively regulates tumour cell invasion and migration in cervical and ovarian cancers.What do the results of this study add? BAG3 expression is closely associated with histogenesis, clinicopathology, and prognosis in gynecological cancers and is involved in signalling pathways associated with the control of cell proliferation, migration, invasion, and drug resistance in tumours.What are the implications of these findings for clinical practice and/or further research? Abnormal BAG3 expression can be employed as a possible marker of tumour development, invasion, and prognosis, providing new ideas for treating cancer.

A bioinformatics analysis of the clinicopathological and prognostic significance of FAM64A mRNA expression in gynecological cancers.

FAM64A is a mitotic regulator which promotes cell metaphase-anaphase transition and is highly expressed in a cell-cycle-dependent manner. In this study, we examined the clinicopathological and prognostic significance of FAM64A mRNA expression in gynecological cancers. We conducted a bioinformatics analysis of FAM64A mRNA expression using Gene Expression Omnibus (GEO), The Cancer Genome Atlas (TCGA), xiantao, The University of ALabama at Birmingham CANcer data analysis Portal (UALCAN), and Kaplan-Meier (KM) plotter databases. FAM64A expression was elevated in breast, cervical, endometrial, and ovarian cancers when compared with normal tissue. Expression was positively correlated with white race, low T stages, infiltrating ductal carcinoma, or favourable PAM50 classification in breast cancer patients, and with clinical stage, histological grade and TP53 mutation, and endometrial cancer serous subtype. FAM64A expression was negatively associated with overall and/or recurrence-free survival rates in breast and endometrial cancer patients, while the opposite was observed in cervical and ovarian cancer patients. FAM64A functioned as an independent predictor of overall and disease-specific survival in breast cancer patients. FAM64A-correlated genes were involved in ligand-receptor interactions, and chromosomal, cell cycle, and DNA replication processes in breast, cervical, endometrial and ovarian cancers. Top hub genes primarily included cell cycle-related proteins in breast cancer, mucins and acetylgalactosaminyl transferases in cervical cancer, kinesin family members in endometrial cancer, and synovial sarcoma X and the cancer/testis antigen in ovarian cancer. FAM64A mRNA expression was positively related to Th2 cell infiltration, but negatively associated with neutrophil and Th17 cell infiltration in breast, cervical, endometrial, and ovarian cancers. FAM64A expression may be considered a potential biomarker reflecting carcinogenesis, histogenesis, aggressive behaviour, and prognosis in gynecological cancers.Impact statementWhat is already known on this subject? FAM64A is located in cell nucleolar and nucleoplasmic regions, and during mitosis it putatively controls metaphase-to-anaphase transition. FAM64A appears to regulate different physiological processes, including apoptosis, tumorigenesis, neural differentiation, stress responses, and the cell cycle.What the results of this study add? FAM64A expression was up-regulated in breast, cervical, endometrial, and ovarian cancers, and positively correlated with white race, low T stages, infiltrating ductal carcinoma, or favourable PAM50 classification in breast cancer patients, and with clinical stage, histological grade, and TP53 mutation, and a serous subtype in endometrial cancer. FAM64A expression was negatively associated with overall and/or recurrence-free survival rates in breast and endometrial cancer patients, while the opposite was observed in cervical and ovarian cancer patients. FAM64A functioned as an independent predictor of overall and disease-specific survival in breast cancer. FAM64A-correlated genes were involved in ligand-receptor interactions, chromosomal, cell cycle, and DNA replication processes, while FAM64A mRNA expression was positively related to Th2 cell infiltration but negatively correlated with neutrophil and Th17 cell infiltration in four gynecological cancers.What the implications of these findings for clinical practice and/or further research? In the future, abnormal FAM64A mRNA expression may serve as a biomarker of carcinogenesis, histogenesis, aggressiveness, and prognosis in gynecological malignancies.

The bioinformatics analysis of the clinicopathological and prognostic significances of REG4 mRNA in gynecological cancers.

To clarify the clinicopathological importance of REG4 mRNA expression, we used GEO, TCGA, xiantao, UALCAN, and Kaplan-Meier plotter for a bioinformatics analysis in breast, cervical, endometrial and ovarian cancers. Compared to normal tissues, REG4 expression was found to be upregulated in breast, cervical, endometrial, and ovarian cancers (p < 0.05). Breast cancer had a higher level of REG4 methylation than normal tissues (p < 0.05), which was negatively correlated with its mRNA expression. REG4 expression was positively correlated with oestrogen and progesterone receptor expression, and aggressiveness of PAM50 classification of breast cancer patients (p < 0.05). Breast infiltrating lobular carcinomas expressed more REG4 than ductal carcinomas (p < 0.05). The REG4-related signal pathways mainly included peptidase, keratinisation, brush border and digestion and so forth in gynecological cancers. Our results indicated that REG4 overexpression was associated with gynecological carcinogenesis and their histogenesis, and may be used as a marker for aggressive behaviour and prognosis of breast or cervical cancer.IMPACT STATEMENTWhat is already known on this subject? REG4 encodes a secretory c-type lectin and plays an essential role in inflammation, carcinogenesis, apoptotic and radiochemotherapeutic resistance.What do the results of this study add? As a standalone predictor, REG4 expression was positively correlated with progression-free survival. Expression of REG4 mRNA was positively associated with the T stage and adenosquamous cell carcinoma of cervical cancer. The top signal pathways related to REG4 included smell and chemical stimulus, peptidase, intermediate filament, and keratinisation in breast cancer; ligand-receptor interaction, metabolism of hormone, xenobiotic and retinol, peptidase, brush border and digestion in cervical and ovarian cancers; bile secretion, intermediate filament, chemical carcinogenesis, brush border and keratinisation in endometrial cancer. REG4 mRNA expression was positively correlated with DC cell infiltration in breast cancer, positively with Th17 cells, TFH, cytotoxic cells and T cells in cervical and endometrial cancers, and negatively with DC cell infiltration, cytotoxic cells and T cells in ovarian cancer. The top hub genes mainly included small proline rich protein 2B in breast cancer; fibrinogens and apoproteins in cervical, endometrial and ovarian cancers.What are the implications of these finding for clinical practice and/or further research? Our study has showed that REG4 mRNA expression is a potential biomarker or therapeutic target for gynaecologic cancers.

Bioinformatic analysis of the clinicopathological and prognostic significance of oocyte-arresting BTG4 mRNA expression in gynecological cancers.

BTG4 arrests the cell cycle and suppresses oocyte and embryonic development. We performed a bioinformatic analysis of BTG4 expression. BTG4 expression was downregulated in breast cancer compared with normal tissues (p < .05), but the opposite was observed in cervical, endometrial and ovarian cancers (p < .05). BTG4 methylation was negatively correlated with its mRNA expression in breast, cervical and endometrial cancers (p < .05). BTG4 mRNA expression was negatively correlated with T staging and distant metastasis of breast cancer; and with tumor invasion, clinical stage, low weight and BMI, low histological grade and no diabetes in endometrial cancer but positively with T stage and non-keratinizing squamous carcinoma in endometrial cancer. BTG4 expression was negatively correlated with the survival of ovarian cancer patients (p < .05), but positively for breast, cervical and endometrial cancers (p < .05). BTG4 expression is thus a potential marker reflecting the carcinogenesis, aggressiveness and prognosis in gynecological cancers.Impact StatementWhat is already known on this subject? Previous studies have revealed the structure and location of BTG4. BTG4 inhibit cell proliferative, promote apoptosis, induce G1 cell cycle arrest. BTG4 promotes the development of mouse embryos from cell stage 1 to 2. The methylation and biological function of BTG4 were clarified in gastric and/or colorectal cancer cells.What do the results of this study add? BTG4 is found to closely link to reflect the carcinogenesis, histogenesis, aggressive behaviors and prognosis of gynecological cancers, and involved in ligand-receptor interaction, microtubule motor activity, dynein light chain binding, cilium organization, assembly, and movement in endometrial and ovarian cancers.What are the implications of these finding for clinical practice and/or further research? Aberrant BTG4 mRNA expression can be employed as a marker of the tumorigenesis, histogenesis, aggressiveness and prognosis of gynecological cancers in the future practice and guide the investigation of BTG4-related signal pathways.

The clinicopathological and prognostic significances of CDC73 expression in breast cancer: A pathological and bioinformatics analysis.

Parafibromin is a protein encoded by the oncosuppressor CDC73 gene, whose mutation results in hyperparathyroidism-jaw tumor syndrome (HPT-JT) and parathyroid carcinoma. Down-regulation of parafibromin is linked to lung, gastric, colorectal, and ovarian cancer tumorigenesis. Parafibromin expression was detected by RT-PCR, bioinformatics analysis, Western blot, and immunohistochemistry; and compared with clinicopathological characteristics of breast cancer. CDC73-related genes and pathways were analyzed using bioinformatics analysis. Parafibromin expression was increased in breast cancer compared to normal tissues at both mRNA and protein levels (p<0.05). Among triple-negative breast cancers, it was higher in basal-like 1 than basal-like 2 patients (p<0.05) and mesenchymal than immunomodulatory patients (p<0.05). CDC73 mRNA expression was positively correlated with white race, non-infiltrating immune cells, favorable luminal subtypes of PAM50, and prognosis of breast cancer patients (p<0.05). The differential genes of CDC73 were classified into enzyme inhibitors, peptidase, and keratinization by KEGG (p<0.05). Similarly, it was classified into ribosomes, TGF-ß, oxidation phosphorylation, inositol phosphate metabolism, arachidonic acid metabolism, linoleic acid metabolism, ERBB, and VEGF signaling pathways by GSEA (p<0.05). The positively-correlated genes of CDC73 were involved in cell mobility, response to interferon α, nuclear pore and basket, and histone methyltransferase. The negatively-correlated genes of CDC73 were involved in the mitochondrial respiratory chain, thermogenesis, and ribosomes. Parafibromin expression was higher in invasive ductal than lobular carcinoma (p<0.05) and mucinous adenocarcinoma than others (p<0.05). Parafibromin immunoreactivity as an independent factor was positively associated with an increased overall survival rate of breast cancer patients (p<0.05). These findings suggest that up-regulation of parafibromin in breast cancer patients is closely linked to a favorable prognosis. It is involved in tumorigenesis and subsequent progression by regulating metabolism, ribosomes, and cytokines.

The roles of BTG1 mRNA expression in cancers: A bioinformatics analysis.

BTG1 (B-cell translocation gene 1) may inhibit proliferation and cell cycle progression, induce differentiation, apoptosis, and anti-inflammatory activity. The goal of this study was to clarify the clinicopathological and prognostic significances of BTG1 mRNA expression and related signal pathways in cancers. Using the Oncomine, TCGA (the cancer genome atlas), xiantao, UALCAN (The University of ALabama at Birmingham Cancer data analysis Portal), and Kaplan-Meier plotter databases, we undertook a bioinformatics study of BTG1 mRNA expression in cancers. BTG1 expression was lower in gastric, lung, breast and ovarian cancer than normal tissue due to its promoter methylation, which was the opposite to BTG1 expression. BTG1 expression was positively correlated with dedifferentiation and histological grading of gastric cancer (p < 0.05), with squamous subtype and young age of lung cancer (p < 0.05), with infrequent lymph node metastasis, low TNM staging, young age, white race, infiltrative lobular subtype, Her2 negativity, favorable molecular subtyping, and no postmenopause status of breast cancer (p < 0.05), and with elder age, venous invasion, lymphatic invasion, and clinicopathological staging of ovarian cancer (p < 0.05). BTG1 expression was negatively correlated with favorable prognosis of gastric, lung or ovarian cancer patients, but the converse was true for breast cancer (p < 0.05). KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis showed that the top signal pathways included cytokine-cytokine receptor interaction, cell adhesion molecules, chemokine, immune cell receptor and NF (nuclear factor)-κB signal pathways in gastric and breast cancer. The top hub genes mainly contained CD (cluster of differentiation) antigens in gastric cancer, FGF (fibroblast growth factor)-FGFR (FGF receptor) in lung cancer, NADH (nicotinamide adenine dinucleotide): ubiquinone oxidoreductase in breast cancer, and ribosomal proteins in ovarian cancer. BTG1 expression might be employed as a potential marker to indicate carcinogenesis and subsequent progression, even prognosis.

The roles of the tumor suppressor parafibromin in cancer.

In this review, we discuss parafibromin protein, which is encoded by CDC73. A mutation in this gene causes hyperparathyroidism-jaw tumor (HPT-JT) syndrome, an autosomal dominant disease. CDC73 is transcriptionally downregulated by the Wilms' tumor suppressor gene WT1 and translationally targeted by miR-182-3p and miR-155. In the nucleus, parafibromin binds to RNA polymerase II and PAF1 complex for transcription. Parafibromin transcriptionally increases the expression of c-Myc, decreases CPEB1 expression by interacting with H3M4, and reduces cyclin D1 expression by binding to H3K9. The RNF20/RNF40/parafibromin complex induces monoubiquitination of H2B-K120, and SHP2-mediated dephosphorylation of parafibromin promotes the parafibromin/ß-catenin interaction and induces the expression of Wnt target genes, which is blocked by PTK6-medidated phosphorylation. Parafibromin physically associates with the CPSF and CstF complexes that are essential for INTS6 mRNA maturation. In the cytosol, parafibromin binds to hSki8 and eEF1Bγ for the destabilization of p53 mRNA, to JAK1/2-STAT1 for STAT1 phosphorylation, and to actinin-2/3 to bundle/cross-link actin filaments. Mice with CDC73 knockout in the parathyroid develop parathyroid and uterine tumors and are used as a model for HPT-JT syndrome. Conditional deletion of CDC73 in mesenchymal progenitors results in embryos with agenesis of the heart and liver while its abrogation in mature osteoblasts and osteocytes increases cortical and trabecular bone. Heterozygous germline mutations in CDC73 are associated with parathyroid carcinogenesis. The rates of CDC73 mutation and parafibromin loss decrease from parathyroid adenoma to atypical adenoma to carcinoma. In addition, down-regulated parafibromin is closely linked to the tumorigenesis, subsequent progression, or poor prognosis of head and neck, gastric, lung, colorectal, and ovarian cancers, and its overexpression might reverse the aggressiveness of these cancer cells. Therefore, parafibromin might be useful as a biological marker of malignancies and a target for their gene therapy.

The oncogenic roles of JC polyomavirus in cancer.

JC polyomavirus (JCPyV) belongs to the human polyomavirus family. Based on alternative splicing, the early region encodes the large and small T antigens, while the late region encodes the capsid structural proteins (VP1, VP2, and VP3) and the agnoprotein. The regulatory transcription factors for JCPyV include Sp1, TCF-4, DDX1, YB-1, LCP-1, Purα, GF-1, and NF-1. JCPyV enters tonsillar tissue through the intake of raw sewage, inhalation of air droplets, or parent-to-child transmission. It persists quiescently in lymphoid and renal tissues during latency. Both TGF-ß1 and TNF-α stimulates JCPyV multiplication, while interferon-γ suppresses the process. The distinct distribution of caspid receptors (α-2, 6-linked sialic acid, non-sialylated glycosaminoglycans, and serotonin) determines the infection capabilities of JCPyV virions, and JCPyV entry is mediated by clathrin-mediated endocytosis. In permissive cells, JCPyV undergoes lytic proliferation and causes progressive multifocal leukoencephalopathy, while its DNA is inserted into genomic DNA and leads to carcinogenesis in non-permissive cells. T antigen targets p53, ß-catenin, IRS, Rb, TGF-ß1, PI3K/Akt and AMPK signal pathways in cancer cells. Intracranial injection of T antigen into animals results in neural tumors, and transgenic mice develop neural tumors, lens tumor, breast cancer, gastric, Vater's, colorectal and pancreatic cancers, insulinoma, and hepatocellular carcinoma. Additionally, JCPyV DNA and its encoded products can be detected in the brain tissues of PML patients and brain, oral, esophageal, gastric, colorectal, breast, cervical, pancreatic, and hepatocellular cancer tissues. Therefore, JCPyV might represent an etiological risk factor for carcinogenesis and should be evaluated for early prevention, diagnosis, and treatment of cancers.

The clinicopathological significances and related signal pathways of BTG3 mRNA expression in cancers: A bioinformatics analysis.

B cell transposition gene 3 (BTG3) is reported to be a tumor suppressor and suppresses proliferation and cell cycle progression. This study aims to analyze the clinicopathological and prognostic significances, and signal pathways of BTG3 mRNA expression in human beings through bioinformatics analysis. We analyzed BTG3 expression using Oncomine, TCGA (the cancer genome atlas), Xiantao, UALCAN (The University of ALabama at Birmingham Cancer data analysis Portal) and Kaplan-Meier plotter databases. Down-regulated BTG3 expression was observed in lung and breast cancers, compared with normal tissues (p < 0.05), but not for gastric and ovarian cancer (p < 0.05). The methylation of BTG3 was shown to be adversely correlated with its mRNA expression (p < 0.05). BTG3 expression was higher in gastric intestinal-type than diffuse-type carcinomas, G1 than G3 carcinomas (p < 0.05), in female than male cancer patients, T1-2 than T3-4, and adenocarcinoma than squamous cell carcinoma of lung cancer (p < 0.05), in invasive ductal than lobular carcinoma, N0 than N1 and N3, TNBC (triple-negative breast cancer) than luminal and Her2+, and Her2+ than luminal cancer of breast cancer (p < 0.05), and G3 than G2 ovarian carcinoma (p < 0.05). BTG3 expression was positively related to the survival rate of gastric and ovarian cancer patients (p < 0.05), but not for breast cancer (p < 0.05). KEGG and PPI (protein-protein interaction) analysis showed that the BTG3 was involved in cell cycle and DNA replication, digestion and absorption of fat and protein, spliceosome and ribosome in cancer. BTG3 expression was positively linked to carcinogenesis, histogenesis, and aggressive behaviors, and was employed to evaluate the prognosis of cancers by regulating cell cycle, metabolism, splicing and translation of RNA.

REG4 promotes the proliferation and anti-apoptosis of cancer.

Regenerating islet-derived 4 (REG4) gene was discovered by high-throughput sequencing of ulcerative colitis cDNA libraries. REG4 is involved in infection and inflammation by enhancing macrophage polarization to M2, via activation of epidermal growth factor receptor (EGFR)/Akt/cAMP-responsive element binding and the killing inflammatory Escherichia coli, and closely linked to tumorigenesis. Its expression was transcriptionally activated by caudal type homeobox 2, GATA binding protein 6, GLI family zinc finger 1, SRY-box transcription factor 9, CD44 intracytoplasmic domain, activating transcription factor 2, and specificity protein 1, and translationally activated by miR-24. REG4 can interact with transmembrane CD44, G protein-coupled receptor 37, mannan and heparin on cancer cells. Its overexpression was observed in gastric, colorectal, pancreatic, gallbladder, ovarian and urothelial cancers, and is closely linked to their aggressive behaviors and a poor prognosis. Additionally, REG4 expression and recombinant REG4 aggravated such cellular phenotypes as tumorigenesis, proliferation, anti-apoptosis, chemoradioresistance, migration, invasion, peritoneal dissemination, tumor growth, and cancer stemness via EGFR/Akt/activator protein-1 and Akt/glycogen synthase kinase three ß/ß-catenin/transcription factor 4 pathways. Sorted REG4-positive deep crypt secretory cells promote organoid formation of single Lgr5 (+) colon stem cells by Notch inhibition and Wnt activation. Histologically, REG4 protein is specifically expressed in neuroendocrine tumors and signet ring cell carcinomas of the gastrointestinal tract, pancreas, ovary, and lung. It might support the histogenesis of gastric intestinal-metaplasia-globoid dysplasia-signet ring cell carcinoma. In this review, we summarized the structure, biological functions, and effects of REG4 on inflammation and cancer. We conclude that REG4 may be employed as a biomarker of tumorigenesis, subsequent progression and poor prognosis of cancer, and may be a useful target for gene therapy.