Therapeutic Target For Colon Cancer Research Articles

BMI1 activates WNT signaling in colon cancer by negatively regulating the WNT antagonist IDAX

Aberrant activation of Wnt signaling plays a critical role in the development of colon cancer. BMI, a component of the polycomb repressive complex (PRC1), is upregulated in various types of cancer and contributes to epigenetic silencing of tumor suppressors. In this study, we showed that BMI1 is upregulated in colon cancer tissues and cell lines. Overexpression of BMI1 in primary epithelial colon cells promotes cellular growth and activates WNT pathway, while BMI1 silencing in colon cancer cells represses these effects. We also found that BMI1 binds to the promoter of IDAX, a Wnt antagonist, and decreases its transcription. Expression of IDAX is downregulated in colon cancer tissues and cell lines and negatively correlated with BMI1 in colon cancer tissues. Furthermore, Silencing of IDAX counteracts the effects of BMI1 suppression, while its overexpression reverses oncogenic effects of BMI1. Together, these findings indicate that BMI1-mediated IDAX epigenetic suppression is crucial for enhancement of colon carcinogenesis, suggesting that BMI1∖IDAX axis as a potential novel diagnostic and therapeutic target of colon cancer.

High Expression of lncRNA AFAP1-AS1 Promotes the Progression of Colon Cancer and Predicts Poor Prognosis.

Long non-coding RNAs (lncRNAs) are dysregulated in various cancers. However, the clinical relevance and functional roles of AFAP1-AS1 in colon cancer (CC) have not been clarified. We analyzed the lncRNA expression patterns in Gene Expression Omnibus (GEO) datasets and the Cancer Genome Atlas (TCGA) RNA-seq datasets, and found that the expression level of AFAP1-AS1 was significantly elevated in CC tissues. High levels of AFAP1-AS1 were associated with poor disease-free survival and overall survival in CC patients. In vitro experiments demonstrated that AFAP1-AS1 knockdown significantly inhibited the cell invasive and migration capability in CC cell line HT-29. AFAP1-AS1 knockdown also increased the expression of E-cadherin and ZO-1 while inhibited the expression of Vimentin, MMP9, ZEB1 and β-catenin, suggesting that AFAP1-AS1 is involved in the epithelial-mesenchymal transition (EMT) process of CC. Further studies confirmed that AFAP1-AS1 knockdown also affected the actin-cytokeratin signaling pathway. Thus, AFAP1-AS1 might be a potential novel diagnostic marker and therapeutic target for CC.

INO80 haploinsufficiency inhibits colon cancer tumorigenesis via replication stress-induced apoptosis.

The INO80 chromatin-remodeling complex performs functions in many chromosomal processes that are crucial for genome stability, such as DNA replication and stalled replication fork recovery. Although these functions suggest that INO80 acts as a tumor suppressor, its specific role in tumorigenesis has remained obscure. Here, we show that a haploinsufficient mutation of Ino80, the catalytic ATPase of the INO80 complex, decreased intestinal adenomatous polyps and increased survival in an Apcmin/+ mouse model of colon cancer. Experiments using tumors obtained from Apcmin/+ mice and cells from human colon cancers showed that this Ino80 defect induced stalled replication forks, the concomitant activation of ATR-Chk1 signaling and an increase in apoptosis, suggesting that Ino80 haploinsufficiency inhibited colon cancer tumorigenesis by activating replication stress-induced ATR-Chk1 signaling to increase apoptosis. Importantly, in human colon cancer, we observed that the INO80 subunits were frequently present in high copy numbers and exhibited a high rate of amplification and increased protein expression. These results show that in contrast to our original prediction that INO80 acts as a tumor suppressor, INO80 actually functions oncogenically to promote colon tumorigenesis. INO80 therefore represents a novel therapeutic target in colon cancer. The results of this study also reinforce the emerging notion that while genomic instability can promote tumorigenesis, in certain genetic contexts, it can also act as a tumor suppressor.

Inhibition of Wnt/\u03b2-Catenin pathway and Histone acetyltransferase activity by Rimonabant: a therapeutic target for colon cancer

In a high percentage (≥85%) of both sporadic and familial adenomatous polyposis forms of colorectal cancer (CRC), the inactivation of the APC tumor suppressor gene initiates tumor formation and modulates the Wnt/β-Catenin transduction pathways involved in the control of cell proliferation, adhesion and metastasis. Increasing evidence showed that the endocannabinoids control tumor growth and progression, both in vitro and in vivo. We evaluated the effect of Rimonabant, a Cannabinoid Receptor 1 (CB1) inverse agonist, on the Wnt/β-Catenin pathway in HCT116 and SW48 cell lines carrying the genetic profile of metastatic CRC poorly responsive to chemotherapies. In these models, Rimonabant inhibited the Wnt/β-Catenin canonical pathway and increased β-Catenin phosphorylation; in HCT116 cells, but not in SW48, the compound also triggered the Wnt/β-Catenin non canonical pathway activation through induction of Wnt5A and activation of CaMKII. The Rimonabant-induced downregulation of Wnt/β-Catenin target genes was partially ascribable to a direct inhibition of p300/KAT3B histone acetyltransferase, a coactivator of β-Catenin dependent gene regulation. Finally, in HCT116 xenografts, Rimonabant significantly reduced tumor growth and destabilized the nuclear localization of β-Catenin. Obtained data heavily supported the rationale for the use of cannabinoids in combined therapies for metastatic CRC harbouring activating mutations of β-Catenin.

CRH promotes human colon cancer cell proliferation via IL-6/JAK2/STAT3 signaling pathway and VEGF-induced tumor angiogenesis.

Corticotrophin-releasing hormone (CRH) has been demonstrated to participate in various diseases. Our previous study showed that its receptor CRHR1 mediated the development of colitis-associated cancer in mouse model. However, the detailed mechanisms remain unclear. In this study, we explored the oncogenetic role of CRH/CRHR1 signaling in colon cancer cells. Cell proliferation and colony formation assays revealed that CRH contributed to cell proliferation. Moreover, tube formation assay showed that CRH-treated colon cancer cell supernatant significantly promoted tube formation of human umbilical vein endothelial cells (HUVECs). And these effects could be reversed by the CRHR1 specific antagonist Antalarmin. Further investigation showed that CRH significantly upregulated the expressions of interlukin-6 (IL-6) and vascular endothelial growth factor (VEGF) through activating nuclear factor-kappa B (NF-κB). The CRH-induced IL-6 promoted phosphorylation of janus kinase 2 (JAK2) and signal transducers and activators of transcription 3 (STAT3). STAT3 inhibition by Stattic significantly inhibited the CRH-induced cell proliferation. In addition, silence of VEGF resulted in declined tube formation induced by CRH. Taken together, CRH/CRHR1 signaling promoted human colon cancer cell proliferation via NF-κB/IL-6/JAK2/STAT3 signaling pathway and tumor angiogenesis via NF-κB/VEGF signaling pathway. Our results provide evidence to support a critical role for the CRH/CRHR1 signaling in colon cancer progression and suggest its potential utility as a new therapeutic target for colon cancer.

MicroRNA-136 inhibits colon cancer cell proliferation and invasion through targeting liver receptor homolog-1/Wnt signaling

An increasing number of studies have reported that microRNAs (miRNAs) are involved in the malignant behavior of colon cancer cells through directly targeting multiple tumor suppressors or oncogenes. The expression and role of miR-136 has been reported in several types of human cancer. However, the role of miR-136 in colon cancer remains unclear. In this study, we aimed to investigate the expression and function of miR-136 in colon cancer and the potential underlying mechanism. Here, we found that miR-136 was decreased in colon cancer cell lines and tissues. Overexpression of miR-136 inhibited the proliferation and invasion in SW480 and HCT116 cell lines while suppression of miR-136 exhibited the opposite effect. Liver receptor homolog-1 (LRH-1) was identified as a direct target gene of miR-136. Notably, miR-136 overexpression suppressed LRH-1 expression as well as Wnt signaling in SW480 and HCT116 cell lines. The miR-136 expression level inversely correlated with LRH-1 mRNA expression in colon cancer specimens. Moreover, overexpression of LRH-1 partially reversed the miR-136-induced antitumor effect in SW480 and HCT116 cell lines. Taken together, these findings suggest that miR-136 functions as a negative regulator in colon cancer progression by targeting LRH-1 and that miR-136 downregulation contributes to high expression of LRH-1 and aberrant activation of Wnt signaling, leaving open the possibility that miR-136 may serve as a potential therapeutic target for colon cancer.

Exo70 is an independent prognostic factor in colon cancer

Exo70, a key component of the Exocyst complex, plays important roles in human cancer progression beyond exocytosis. However, the expression of Exo70 and its prognostic value for patients with colon cancer has not been well investigated to date. In this study, we observed that the mRNA and protein levels of Exo70 were upregulated in 11 of 13 colon cancer tissues, compared with their normal counterparts, which was validated by immunohistochemical analysis in a tissue microarray containing 89 pairs of colon cancer tissues and the matched adjacent normal tissues. Statistical analysis revealed that Exo70 expression is positively correlated with tumor size, invasion depth, TNM stage and distant metastasis. Kaplan-Meier survival analysis showed that colon cancer patients with higher Exo70 expression have a poorer clinical outcome than those with lower Exo70 expression. Multivariate Cox regression analysis revealed that Exo70, age and distant metastasis were there independent prognostic factors for overall survival rate of colon cancer patients. Through gain- and loss of Exo70 in colon cancer cells, we found that Exo70 could enhance the migration ability of colon cancer cells. Taken together, our studies revealed that Exo70 might be a promising negative prognostic factor and a potential therapeutic target for colon cancer.

Abstract 4143: Mastl, a novel therapeutic target in colon cancer

Abstract Combining chemoradiation with agents that modulate tumor-specific pathways such as cell cycle checkpoints has shown immense promise in preclinical and clinical studies. To ensure that only healthy cells proliferate, checkpoints have evolved that induce cell-cycle arrest in response to the detection of defects that may have arisen during DNA replication or other steps leading to mitosis. The G2/M checkpoint Mastl in mammals (and Greatwall in Xenopus and Drosophila) prevents cells from premature entry into mitosis, and thus minimizes chromosome mis-segregation. Our preliminary data demonstrate that Mastl not only plays a key role in regulating cell cycle and mitosis but also regulates key oncogenic signaling pathways and assists therapy resistance in cancer cells. Interestingly, genetic elimination of Mastl expression in vivo compromised survival in young mice, however, only mild alterations were found when deleted in adult mice. Here we show using two clinical and genomic databases using a total of 265 patient samples that Mastl expression increases in colon cancer across all cancer stages compared with the normal colon tissue (P < 0.001). Moreover, high Mastl expression associates with high-risk colorectal cancer patients and poor prognosis. Silencing of Mastl expression using gene-specific shRNA, in two different colon cancer cells with high endogenous expression of Mastl, induced cell death/apoptosis supporting important role of Mastl in colon cancer cell survival. To further determine molecular mechanism/s by which Mastl regulates cell survival, we screened a panel of oncogenes. It was interesting that the knock-down of Mastl expression sharply inhibited β-catenin/c-myc signaling, key regulators of colon carcinogenesis, in both cell types. To further expand the breadth of this investigation and to identify additional key players in Mastl dependent regulation of colon cancer cell survival, we performed an oncogenic array analysis using above cell lines with or without stable inhibition of Mastl expression. Here, we observed robust effects of inhibiting Mastl upon anti-apoptotic proteins Bcl-xl and survivin. Notably, c-myc regulates survivin and Bcl-xl expressions. Additional studies, where colon cancer cells were subjected to 5-FU treatment sharply induced Mastl expression and combinational therapy using 5FU and (targeting) Mastl resulted in significantly increased death among these cells (P>0.0025; versus control). Taken together, we here report a novel and previously undescribed role of Mastl in colon cancer progression, malignancy and therapy resistance potentially by regulating cell survival in manners dependent on β-catenin/c-Myc/Survivin/Bcl-xl signaling. Citation Format: JayaPrakash Uppada, SaiPrasad Gowrikumar, Rizwan Ahmad, Steven Chen, J Joshua Smith, Amar B. Singh, Punita Dhawan. Mastl, a novel therapeutic target in colon cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4143. doi:10.1158/1538-7445.AM2017-4143

Loss of periplakin expression is associated with the tumorigenesis of colorectal carcinoma.

Periplakin (PPL), a member of the plakin protein family, has been reported to be down-expressed in urothelial carcinoma. The role of PPL in human colorectal cancer, however, remains largely unknown. Also little is known about the contribution of PPL to the malignant property of colorectal cancer and the intracellular function of PPL. In this study, we demonstrated that PPL was apparently down-expressed in colon carcinomas compared with normal and para-carcinoma tissues, which was correlated with the tumor size. Enforced expression of PPL in HT29 cells inhibited its proliferation evidenced by decreased expression of phosphorylated ERK and PCNA. Furthermore, PPL overexpression could reduce metastasis and epithelial-mesenchymal transition (EMT) of HT29 cells, with decreased expression of N-cadherin, Snail, Slug and α-SMA while increased expression of E-cadherin. On the contrary, the PPL knockdown could promote the cell proliferation, migratory, invasive and EMT ability of HT29 cells. Moreover, enforced expression of PPL induced G1/G0 cell cycle arrest, with decreased cyclin D1, p-Rb and increased expression of p27kib, which could be reversed by PPL knockdown. In addition, PPL overexpression inhibited the growth of colon cancer allograft in vivo. Taken together, acted as a tumor suppressor in colon cancer progression, PPL could be a new biomarker or potential therapeutic target in colon cancer.

Covering the Cover

Covering the Cover

The Significant Pathways and Genes Underlying the Colon Cancer Treatment by the Traditional Chinese Medicine PHY906.

Background We attempted to explore the molecular mechanism underlying PHY906 intervention of colon cancer. Methods The microarray data of tumors treated by PHY906 and PBS alone were downloaded from the public Gene Expression Omnibus database. The dataset was further analyzed for the differentially expressed genes (DEGs) and their related biological functions were analyzed, followed by function and pathways. Protein-protein interaction (PPI) network was constructed and the significant nodes were screened by network centralities and then the significant modules analysis. Besides, they were clustered and transcriptional factors (TFs) were predicted. Results The gene expression patterns changed induced by PHY906 treatment, including 414 upregulated and 337 downregulated DEGs. The biological process of response to steroid hormone stimulus and regulation of interferon-gamma production were significantly enriched by DEGs. Ezh2 (enhancer of zeste 2) was found to be the key node in PPI network. There are 12 significant TFs predicted for module 1 genes and 3 TFs for module 2 genes. Conclusions PHY906 treatment may function in protecting the epithelial barrier against tumor cell invasion by modulating IFN-γ level and mediating cancer cell death by activating the response to steroid hormone stimulus and activating the response to steroid hormone stimulus. E2f1, Hsfy2, and Nfyb may be therapeutic targets for colon cancer. PHY906 showed treatment efficacy in modulating cell apoptosis by intervening interferon-gamma production and response to steroid hormone stimulus. Ezh2 and its TFs such as E2f1, Hsfy2, and Nfyb may be the potential therapeutic targets for anticancer agents development.

MAEL expression links epithelial-mesenchymal transition and stem cell properties in colorectal cancer.

MAEL plays a central role during spermatogenesis by repressing transposable elements and preventing their mobilisation, however, its role on cancers is unclear. In this study, MAEL expression was analysed in a tissue microarray containing 185 samples of primary colon cancer tumor samples and human colon cancer cell lines. The effect of MAEL on cell proliferation, tumorigenesis, metastasis and drug resistance was examined in vitro and in vivo. Immunoprecipitation assay, confocal immunofluorescent analysis and luciferase assay were used for mechanism study. As results, MAEL was significantly upregulated in colon cancer patient tissue samples, and elevated MAEL protein levels positively correlated with overall survival and disease free survival of colon cancer patients. Using in vitro and in vivo models, we demonstrated that MAEL expression was correlated with cell proliferation, invasion and drug resistance of colon cancer cells by inducing epithelial-mesenchymal transition and stemness characteristics. Mechanistically, our study demonstrated that MAEL interacts with Snail and inhibit E-cadherin promoter activity. Collectively, MAEL is an oncogene that plays an important role in the development and progression of colon cancer, which may be a novel potential therapeutic target for colon cancer.

Epidermal growth factor is a critical regulator of the cytokine IL-33 in intestinal epithelial cells.

IL-33 is a novel cytokine that is believed to be involved in inflammation and carcinogenesis. However, its source, its production and its secretion process remain unclear. Recently, we have reported that IL-33 is up-regulated in dextran sulfate sodium (DSS) colitis in mice. Production of IL-33 from intestinal tissue was studied in a murine cancer model induced by azoxymethane (AOM) and DSS in vivo and in cultures of IEC-6 epithelial cells. Cytokine levels were measured by real time PCR, immunohistochemistry and elisa. Mice with AOM/DSS-induced colitis expressed all the characteristic symptoms of colon cancer pathology. Immunohistochemical analysis demonstrated epithelial cell-derived IL-33 in colon tissues from mice with AOM/DSS colitis. Real time PCR and quantitative PCR analysis revealed that AOM/DSS colitis tissues expressed up-regulated IL-1β, IL-33, TGF-β, and EGF mRNA. Gefitinib, an EGFR inhibitor, inhibited IL-33 mRNA expression in AOM/DSS colitis mice. The pathophysiological role of IL-33 in the rat intestinal epithelial cell line (IEC-6 cells) was then investigated. We found that EGF, but not TGF-β1 or PDGF, greatly enhanced mRNA expression of IL-33 and its receptor ST2. In accordance with the gene expression and immunohistochemical analysis of IL-33 levels, elisa-based analysis of cytoplasmic and nuclear extracts showed increased IL-33 protein levels in IEC-6 cells after treatment with EGF. Our results suggest that EGF is a key growth factor that increased IL-33 production and ST2 receptor expression during intestinal inflammation and carcinogenesis. The EGF/IL-33/ST2 axis represents a novel therapeutic target in colon cancer.

SRPK2 promotes the growth and migration of the colon cancer cells

Colon cancer is one of the major causes of cancer-related death in the world. Understanding the molecular mechanism underlying this malignancy will facilitate the diagnosis and treatment. Serine-arginine protein kinase 2 (SRPK2) has been reported to be upregulated in several cancer types. However, its expression and functions in colon cancer remains unknown. In this study, it was found that the expression of SRPK2 was up-regulated in the clinical colon cancer samples. Overexpression of SRPK2 promoted the growth and migration of colon cancer cells, while knocking down the expression of SRPK2 inhibited the growth, migration and tumorigenecity of colon cancer cells. Molecular mechanism studies revealed that SRPK2 activated ERK signaling in colon cancer cells. Taken together, our study demonstrated the tumor promoting roles of SRPK2 in colon cancer cells and SRPK2 might be a promising therapeutic target for colon cancer.

Activation of TIM1 induces colon cancer cell apoptosis via modulating Fas ligand expression

The pathogenesis of colon cancer is unclear. It is proposed that TIM1 has an association with human cancer. The present study aims to investigate the role of TIM1 activation in the inhibition of human colon cancer cells. In this study, human colon cancer cell line, HT29 and T84 cells were cultured. The expression of TIM1 was assessed by real time RT-PCR and Western blotting. The TIM1 on the cancer cells was activated in the culture by adding recombinant TIM4. The chromatin structure at the FasL promoter locus was assessed by chromatin immunoprecipitation. The apoptosis of the cancer cells was assessed by flow cytometry. The results showed that human colon cancer cell lines, HT29 cells and T84 cells, expressed TIM1. Activation of TIM1 by exposing the cells to TIM4 significantly increased the frequency of apoptotic colon cancer cells. The expression of FasL was increased in the cancer cells after treating by TIM4. Blocking Fas or FasL abolished the exposure to TIM4-induced T84 cell apoptosis. In conclusion, HT29 cells and T84 cells express TIM1; activation TIM1 can induce the cancer cell apoptosis. TIM1 may be a novel therapeutic target of colon cancer.

MicroRNA-155 deletion promotes tumorigenesis in the azoxymethane-dextran sulfate sodium model of colon cancer

Clinical studies have linked microRNA-155 (miR-155) expression in the tumor microenvironment to poor prognosis. However, whether miR-155 upregulation is predictive of a pro- or antitumorigenic response is unclear, as the limited preclinical data available remain controversial. We examined miR-155 expression in tumor tissue from colon cancer patients. Furthermore, we investigated the role of this microRNA in proliferation and apoptosis, inflammatory processes, immune cell populations, and transforming growth factor-β/SMAD signaling in a chemically induced (azoxymethane-dextran sulfate sodium) mouse model of colitis-associated colon cancer. We found a higher expression of miR-155 in the tumor region than in nontumor colon tissue of patients with colon cancer. Deletion of miR-155 in mice resulted in a greater number of polyps/adenomas, an increased symptom severity score, a higher grade of epithelial dysplasia, and a decrease in survival. Surprisingly, these findings were associated with an increase in apoptosis in the normal mucosa, but there was no change in proliferation. The protumorigenic effects of miR-155 deletion do not appear to be driven solely by dysregulation of inflammation, as both genotypes had relatively similar levels of inflammatory mediators. The enhanced tumorigenic response in miR-155(-/-) mice was associated with alterations in macrophages and neutrophils, as markers for these populations were decreased and increased, respectively. Furthermore, we demonstrated a greater activation of the transforming growth factor-β/SMAD pathway in miR-155(-/-) mice, which was correlated with the increased tumorigenesis. Given the multiple targets of miR-155, careful evaluation of its role in tumorigenesis is necessary prior to any consideration of its potential as a biomarker and/or therapeutic target in colon cancer.

MicroRNA‑7 suppresses human colon cancer invasion and proliferation by targeting the expression of focal adhesion kinase.

Previous studies have demonstrated that microRNA (miRNA) are essential in tumor development and invasion. The close association between focal adhesion kinase (FAK) and colon cancer (CC) has been previously reported. miRNA-7 (miR-7) inhibits the translation of FAK protein. Therefore, the present study aimed to assess the underlying molecular mechanism of miR-7 in human CC cell lines, to provide a novel therapeutic biomarker of CC in the future. The present study detected the expression of miR-7 in 60 CC tissues by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The association between the expression of miR-7 and clinical pathological factors was analyzed. Overexpression/underexpression of miR-7 were established by transfecting miR-7mimics/inhibitors into HCT-8 and Caco-2 cells. The transfected CC cell lines were used in cell viability and scratching assays. The regulation of FAK by miR-7 was analyzed by western blotting and RT-qPCR. It was demonstrated that the expression of miR-7 negatively correlated with lymph node metastasis and tumor node metastasis staging in CC (P<0.05). Inhibition of miR-7 led to an accelerated ability of proliferation and migration in CC cell lines. Additionally, overexpression of miR-7 inhibited the proliferation and migration of CC cells. In addition, it was also observed that miR-7 regulated the proliferation and migration of CC by regulating the protein expression of FAK, therefore, regulating the expression of matrix metalloproteinase (MMP)-2 and MMP-9. miR-7 inhibited the proliferation and migration of CC cells by regulating FAK. These findings suggested that miR-7 may be a novel therapeutic target for CC.

Karyopherin alpha 2 is a novel prognostic marker and a potential therapeutic target for colon cancer.

BackgroundKaryopherin alpha 2 (KPNA2), a member of the karyopherin family, plays a vital role in carcinogenesis. Yet its role in colon cancer is poorly characterized. We sought to clarify the clinical significance of its dysregulated expression in human colon tumor specimens.MethodsWe evaluated KPNA2 mRNA and protein expression by real-time polymerase chain reaction and Western blotting in 40 primary colon cancer tissues and paired adjacent normal colon mucosa specimens. KPNA2 protein expression in colon tissue microarray of tumor and normal tissue specimens and lymph node metastasis specimens obtained from 195 colon cancer patients were analyzed immunohistochemically. The effect of KPNA2 knockdown on carcinogenesis potential of human colon cancer cells was determined using Cell Counting Kit-8 (CCK8), colony formation, cell migration, and tumorigenesis in nude mice.ResultsKPNA2 was expressed at higher levels in colon tumors and lymph node metastasis specimens than in normal tissues. Patients with KPNA2-positive tumors were significantly correlated with the American Joint Committee on Cancer (AJCC) stage (p = 0.01), T-classification (p = 0.018), regional lymph node metastasis (p = 0.025), distant metastasis (p = 0.014), and differentiated degree (p = 0.001). KPNA2 was shown to be an independent prognostic indicator of disease-free survival (HR 1.681; 95 % CI: 1.170–2.416; p = 0.005) and overall survival (HR 2.770; 95 % CI: 1.314–5.837; p = 0.007) for patients with colon cancer. Knockdown of KPNA2 expression inhibited colon cancer cell proliferation, colony formation, and migration.ConclusionKPNA2 might play an important role in colorectal carcinogenesis and functions as a novel prognostic indicator and a potential therapeutic target for colorectal cancer.

ARMc8 indicates aggressive colon cancers and promotes invasiveness and migration of colon cancer cells.

Recent studies have implicated ARMc8 in promoting tumor formation in non-small cell lung cancer and breast cancer; however, so far, no studies have revealed the expression pattern or cellular function of ARMc8 in colon cancer. In this study, we used immunohistochemical staining to measure ARMc8 expression in 206 cases of colon cancer and matched adjacent normal colon tissue. Clinically important behaviors of cells, including invasiveness and migration, were evaluated after upregulation of ARMc8 expression in HT29 cells through gene transfection or downregulation of expression in LoVo cells using RNAi. We found that ARMc8 was primarily located in the membrane and cytoplasm of tumor cells, and its expression level was significantly higher in colon cancer in comparison to that in the adjacent normal colon tissues (p < 0.001). ARMc8 expression was closely related to TNM stage (p = 0.006), lymph node metastasis (p = 0.001), and poor prognosis (p = 0.002) of colon cancer. The invasiveness and migration capacity of HT29 cells transfected with ARMc8 were significantly greater than those of control cells (p < 0.001), while ARMc8 siRNA treatment significantly reduced cell invasion and migration in LoVo cells (p < 0.001). Furthermore, we demonstrated that ARMc8 could upregulate the expression of MMP7 and snail and downregulate the expression of p120ctn and α-catenin. Therefore, ARMc8 probably enhanced invasiveness and metastatic capacity by affecting these tumor-associated factors, thereby playing a role in enhancing the tumorigenicity of colon cancer cells. ARMc8 is likely to become a potential therapeutic target for colon cancer.

Developmental pluripotency-associated 4: a novel predictor for prognosis and a potential therapeutic target for colon cancer.

BackgroundsDevelopmental pluripotency-associated 4 (Dppa4) gene plays an important role in self-renewal and pluripotency sustainability in embryonic stem cells. It is re-expressed in several malignant tumors and is identified as a new pluripotency-related oncogene. The present study investigates the expression and clinical significance of Dppa4 in colon cancer.MethodsReal-time polymerase chain reaction and Western blotting were used to evaluate Dppa4 mRNA and protein expression in 39 pairs of fresh-frozzen colon cancer samples, which were compared with adjacent normal mucosa. The Dppa4 protein was evaluated by immunohistochemical techniques using colon tissue microarrays (TMA). The sample included 185 cancer specimens and corresponding normal colorectal mucosa. The effect of Dppa4 knockdown on colorectal cancer cell proliferation was investigated using Cell Counting Kit-8 (CCK8) assays and colony-formation assays.ResultsBoth the mRNA and protein level expression of Dppa4 gene was found to be upregulated in colon cancer tissues. Furthermore, the upregulated expression of Dppa4 was significantly correlated with the results of American Joint Committee on Cancer (AJCC) stage (P = 0.01), invasion depth (P = 0.028), nodal involvement (P = 0.012), distant metastasis (P = 0.003), and differentiation (P = 0.002). Dppa4 was also shown to be an independent prognostic indicator of disease-free survival (HR 6.118, 95 % CI 3.004–12.462) and overall survival (HR 6.348, 95 % CI 2.875–14.014) for patients with colon cancer. Knockdown of Dppa4 expression inhibited the proliferation of colorectal cancer cell lines through G1/S transition regulation.ConclusionThe results indicate that Dppa4 might play an important role in colon cancer progression and function as a novel prognostic indicator and a potential therapeutic target.