Differential expression of DUSP2 in left- and right-sided colon cancer is associated with poor prognosis in colorectal cancer

Complexation of histone deacetylase inhibitor belinostat to Cu(II) prevents premature metabolic inactivation in vitro and demonstrates potent anti-cancer activity in vitro and ex vivo in colon cancer

PURPOSE

The histone deacetylase inhibitor (HDACi), belinostat, has had limited therapeutic impact in solid tumors, such as colon cancer, due to its poor metabolic stability. Here we evaluated a novel belinostat prodrug, copper-bis-belinostat (Cubisbel), in vitro and ex vivo, designed to overcome the pharmacokinetic challenges of belinostat.

METHODS

The in vitro metabolism of each HDACi was evaluated in human liver microsomes (HLMs) using mass spectrometry. Next, the effect of belinostat and Cubisbel on cell growth, HDAC activity, apoptosis and cell cycle was assessed in three colon cancer cell lines. Gene expression alterations induced by both HDACis were determined using RNA-Seq, followed by in silico analysis to identify master regulators (MRs) of differentially expressed genes (DEGs). The effect of both HDACis on the viability of colon cancer patient-derived tumor organoids (PDTOs) was also examined.

RESULTS

Belinostat and Cubisbel significantly reduced colon cancer cell growth mediated through HDAC inhibition and apoptosis induction. Interestingly, the in vitro half-life of Cubisbel was significantly longer than belinostat. Belinostat and its Cu derivative commonly dysregulated numerous signalling and metabolic pathways while genes downregulated by Cubisbel were potentially controlled by VEGFA, ERBB2 and DUSP2 MRs. Treatment of colon cancer PDTOs with the HDACis resulted in a significant reduction in cell viability and downregulation of stem cell and proliferation markers.

CONCLUSIONS

Complexation of belinostat to Cu(II) does not alter the HDAC activity of belinostat, but instead significantly enhances its metabolic stability in vitro and targets anti-cancer pathways by perturbing key MRs in colon cancer. Complexation of HDACis to a metal ion might improve the efficacy of clinically used HDACis in patients with colon cancer.

TRIM29 is differentially expressed in colorectal cancers of different primary locations and affects survival by regulating tumor immunity based on retrospective study and bioinformatics analysis

Background

In colorectal cancer (CRC) patients, different primary tumor locations caused distinct prognosis and clinicopathological features. It is necessary to identify specific tumor markers according tumor site. Our previous work has identified differentially expressed genes between CRC and adjacent normal tissues, in which only TRIM29 was differently expressed between right colon cancer (RCC) and left colon cancer (LCC) patients. Rectal cancer (RECC) was not included in this latter study and the effects of TRIM29 on the survival with RCC and LCC patients were not investigated. This study further verified TRIM29 expression through Gene Expression Omnibus (GEO) database and our retrospective study. The role of TRIM29 on survival according tumor sites was also explored. Furthermore, the molecular mechanisms of TRIM29 were explored.

Methods

The GEO dataset was used to confirm the differential expression of TRIM29 in proximal and distal cancers. Moreover, TRIM29 were assess using immunohistochemistry (IHC) in 227 cases to observe the correlation between TRIM29 and tumor site. The relationship between TRIM29 and the clinicopathologic features was investigated according tumor sites. Furthermore, the disease-free survival (DFS) and overall survival (OS) was analyzed using the Kaplan-Meier method to assess the prognostic value of TRIM29. Finally, bioinformatics analysis was used to explore the molecular mechanisms. The Tumor-Immune System Interactions and Drug Bank database (TISIDB) was used to analyze the correlations between TRIM29 expression and tumor immune functions. The correlation of TRIM29 with tumor infiltrating lymphocytes or mismatch-repair-proficient/mismatch-repair-deficient (pMMR/dMMR) status was also investigated.

Results

TRIM29 expression was significantly higher in patients with RCC (P<0.001). RCC patients with high TRIM29 tended to be older, male, in stage III-IV, with N+ staging, and intestinal obstruction (P<0.001, P<0.001, P<0.001, P<0.001, and P=0.010, respectively). High TRIM29 expression was associated with an increased risk of recurrence/metastasis and death, only in RCC patients (P=0.020 and P<0.001). Functional annotations and immune activity analysis showed that TRIM29 is related to tumor infiltrating lymphocytes and immune dysfunction.

Conclusions

TRIM29 plays varying roles in patients with different tumor sites. TRIM29 is correlated with the clinicopathological features and prognosis in RCC patients. Indeed, TRIM29 may serve as a new biomarker for RCC patients.

Dual-specificity phosphatases: therapeutic targets in cancer therapy resistance

PURPOSE

Therapy resistance is the principal obstacle to achieving cures in cancer patients and its successful tackling requires a deep understanding of the resistance mediators. Increasing evidence indicates that tumor phosphatases are novel and druggable targets in translational oncology and their modulation may hinder tumor growth and motility and potentiate therapeutic sensitivity in various neoplasms via regulation of various signal transduction pathways. Dual-specificity phosphatases (DUSPs) are key players of cell growth, survival and death and have essential roles in tumor initiation, malignant progression and therapy resistance through regulation of the MAPK signaling pathway. In this review, different aspects of DUSPs are discussed.

METHODS

A comprehensive literature review was performed using various websites including PubMed.

RESULTS

We provide mechanistic insights into the roles of well-known DUSPs in resistance to a wide range of cancer therapeutic approaches including chemotherapy, radiation and molecular targeted therapy in human malignancies. Moreover, we discuss the development of DUSP modulators, with a focus on DUSP1 and 6 inhibitors. Ultimately, the preclinical investigations of small molecule inhibitors of DUSP1 and 6 are outlined.

CONCLUSION

Emerging evidence indicates that the DUSP family is aberrantly expressed in human malignancies and plays critical roles in determining sensitivity to a wide range of cancer therapeutic strategies through regulation of the MAPK signaling pathways. Consequently, targeting DUSPs and their downstream molecules can pave the way for more effective cancer therapies.

Expression of Dual-Specificity Phosphatase 2 (DUSP2) in Patients with Serous Ovarian Carcinoma and in SKOV3 and OVCAR3 Cells In Vitro

BACKGROUND Ovarian cancer commonly presents at a late stage and is associated with poor prognosis. The most common histological subtype is serous ovarian carcinoma. Dual-specificity phosphatase 2 (DUSP2) is a protein phosphatase and substrate for mitogen-activated protein kinases (MAPKs) with increased expression levels in malignancy. This study aimed to evaluate the expression of DUSP2 in tumor tissues from patients with serous ovarian carcinoma and the association with tumor grade, stage, and patient survival and to investigate the effects of DUSP2 expression in SKOV3 and OVCAR3 cells in vitro. MATERIAL AND METHODS Tumor tissue and adjacent normal ovarian tissue from 127 patients with histologically confirmed serous ovarian carcinoma underwent quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry to measure DUSP2 mRNA and protein expression, respectively. Tumor grade, stage, and clinicopathological data underwent correlation analysis with DUSP2 expression, and survival data were assessed with Kaplan-Meier and Cox regression analysis. The effects of DUSP2 expression on the proliferation and migration of SKOV3 and OVCAR3 cells were evaluated. RESULTS Immunohistochemistry showed that DUSP2 was down-regulated in serous ovarian carcinoma tissues compared with adjacent ovarian tissues, and was significantly correlated with tumor stage. Survival analysis showed that DUSP2 expression was an independent risk factor for patient survival. DUSP2 expression in SKOV3 and OVCAR3 cells in vitro suppressed cell proliferation and migration. CONCLUSIONS Down-regulation of DUSP2 expression in serous ovarian carcinoma was an independent risk factor for patient survival, and its expression in SKOV3 and OVCAR3 cells inhibited cell proliferation and migration in vitro.

Identification of Potential Prostate Cancer-Related Pseudogenes Based on Competitive Endogenous RNA Network Hypothesis

BACKGROUND Long noncoding RNAs (lncRNAs) have been revealed to function as competing endogenous RNAs (ceRNAs), which can seclude the common microRNAs (miRNAs) and hence prevent the miRNAs from binding to their ancestral gene. Nonetheless, the role of lncRNA-mediated ceRNAs in prostate cancer has not yet been elucidated. MATERIAL AND METHODS Using The Cancer Genome Atlas (TCGA) database, lncRNA, miRNA, and mRNA profiles from 499 prostate cancer tissues and 52 normal prostate tissues were analyzed with the R package "DESeq" to identify the differentially expressed RNAs. GO and KEGG pathway analyses were performed using "DAVID6.8" and R packages "Clusterprofile." The ceRNA network in prostate cancer was constructed using miRDB, miRTarBase, and TargetScan databases. Survival analysis was performed with Kaplan-Meier analysis. RESULTS A total of 376 lncRNAs, 33 miRNAs, and 687 mRNAs were identified as significant factors in tumorigenesis. Based on the hypothesis that the ceRNA network (lncRNA-miRNA-mRNA regulatory axis) is involved in prostate cancer and forms competitive interrelations between miRNA and mRNA or lncRNA, we constructed a ceRNA network that included 23 lncRNAs, 6 miRNAs, and 2 mRNAs that were differentially expressed in prostate cancer. Only 3 lncRNAs (LINC00308, LINC00355, and OSTN-AS1) had a significant association with survival (P<0.05). The 3 prostate cancer-specific lncRNA were validated in prostate cancer cell lines PC3 and DU145 using qRT-PCR. CONCLUSIONS We demonstrated the differential lncRNA expression profiles in prostate cancer, which provides new insights for future studies of the ceRNA network and its regulatory mechanisms in prostate cancer.