The EF-hand calcium-binding protein tescalcin is a potential oncotarget in colorectal cancer

TESC acts as a prognostic factor and promotes epithelial-mesenchymal transition progression in esophageal squamous carcinoma

BACKGROUND

Tescalcin (TESC) is a critical regulator of cell differentiation and growth, promoting malignant progression in various tumors. However, the role of TESC in esophageal squamous carcinoma (ESCC) remains unclear.

METHODS

Immunohistochemistry (IHC), quantitative real-time PCR (qRT-PCR), and western blot were utilized to identify the difference in TESC expression between ESCC tissues and normal tissues adjacent to the carcinoma. The relationship between TESC and several clinicopathological features was shown by the chi-square test. Log-rank analysis and Cox regression were used to detect the relationship between TESC and the prognosis in ESCC. Clone formation and cell count kit-8 (CCK-8) were applied to detect the impact of TESC on ESCC proliferation. Wound healing assay and transwell assay were used to confirm the influence of TESC on the invasion and migration. Spearman correlation coefficient was used to describe the correlation between TESC and epithelial-mesenchymal transition (EMT)-related protein expression in ESCC. Western blot was used to detect the effect of TESC on the expression of E-cadherin, N-cadherin, and Vimentin as well as AKT signaling pathway. Xenograft tumors were developed to test the pro-tumorigenic impacts of TESC in vivo.

RESULTS

TESC was upregulated expression in ESCC tissues and was linked to poorer prognosis and worse tumor infiltration, TNM stage, and lymph node metastasis. Meanwhile, TESC was able to act as an independent prognostic factor in ESCC. TESC promoted tumor cell proliferation, invasion, migration, EMT progression, and activated the phosphorylation of the AKT pathway. Furthermore, TESC knockdown inhibited the growth of carcinoma in vivo.

CONCLUSION

TESC is a predictive factor for poor prognosis in ESCC and may provide a new strategy for ESCC treatment.

TESC promotes differentiated thyroid cancer development by activating ERK and weakening NIS and radioiodine uptake

PURPOSE

Most differentiated thyroid cancer (DTC) patients have a good prognosis after surgery, but radioiodine refractory differentiated thyroid cancer (RAIR-DTC) patients have a significantly reduced 5-year survival rate (<60%) and a significantly increased recurrence rate (>30%). This study aimed to clarify the tescalcin (TESC) role in promoting the malignant PTC progression and providing a potential target for RAIR-DTC treatment.

METHODS

We analyzed TESC expression and clinicopathological characteristics using the Cancer Genome Atlas (TCGA) and performed qRT-PCR on tissue samples. TPC-1 and IHH-4 proliferation, migration, and invasion were detected after transfection with TESC-RNAi. Using Western blot (WB), several EMT-related indicators were detected. Moreover, iodine uptake of TPC-1 and IHH-4 after transfection with TESC-RNAi was detected. Finally, NIS, ERK1/2, and p-ERK1/2 levels were determined by WB.

RESULTS

TESC was significantly upregulated in DTC tissues and positively correlated with BRAF V600E mutation based on data analysis from TCGA and our center. Reduced expression of TESC in both IHH-4 (BRAF V600E mutation) and TPC-1 (BRAF V600E wild type) cells significantly inhibited cell proliferation, migration, and invasion. It downregulated the EMT pathway markers Vimentin and N-cadherin, and increased E- cadherin. Moreover, TESC knockdown significantly inhibited ERK1/2 phosphorylation and decreased NIS expression in DTC cells, with a remarkably increased iodine uptake rate.

CONCLUSIONS

TESC was highly expressed in DTC tissues and may have promoted metastasis through EMT and induced iodine resistance by downregulating NIS in DTC cells.

Multi-omics analysis of fecal samples in colorectal cancer Egyptians patients: a pilot study

BACKGROUND

Colorectal cancer (CRC) is a public health concern and the second most common disease worldwide. This is due to genetic coding and is influenced by environmental aspects, in which the gut microbiota plays a significant role. The purpose of this study was to compare the microbiota makeup of CRC patients with that of healthy control and to identify upregulated and downregulated proteins and metabolites in CRC patients. Using a next-generation sequencing approach, fecal samples of five females (4 CRC patients and one healthy control) were analyzed by BGI DNBSEQ-T7, Hong Kong, China. Furthermore, proteomics and metabolomics analysis were performed using LC-MS/MS technique.

RESULTS

Dysbiosis of gut microbiota has been observed in patients with CRC, with an increase in microbiota diversity at all taxonomic levels relative to healthy control. Where, at the functional level the bacterial species participate in many different pathways among them de novo nucleotide synthesis and amino acids pathways were aberrantly upregulated in CRC patients. Proteomics and metabolomics profiles of CRC patients showed different proteins and metabolites, a total of 360 and 158 proteins and metabolites, respectively were highly expressed compared to healthy control with fold change ≥ 1.2. Among the highly expressed proteins were transketolase, sushi domain-containing protein, sulfide quinone oxidoreductase protein, AAA family ATPase protein, carbonic anhydrase, IgG Fc-binding protein, nucleoside diphosphate kinase protein, arylsulfatase, alkaline phosphatase protein, phosphoglycerate kinase, protein kinase domain-containing protein, non-specific serine/threonine protein kinase, Acyl-CoA synthetase and EF-hand domain-containing protein. Some of the differential metabolites, Taurine, Taurocholic acid, 7-ketodeoxycholic acid, Glycochenodeoxycholic acid, Glycocholic acid, and Taurochenodeoxycholic acid that belong to bile acids metabolites.

CONCLUSIONS

Some bacterial species, proteins, and metabolites could be used as diagnostic biomarkers for CRC. Our study paves an insight into using multi-omics technology to address the relationship between gut microbiota and CRC.

Tescalcin promotes highly invasive papillary thyroid microcarcinoma by regulating FOS/ERK signaling pathway

Background

Part of papillary thyroid microcarcinoma (PTMC) has a high risk of tumor invasion and metastasis, which may occur in the regional lymph node metastasis or distant metastasis, severely threatening the life of patients. Invasion and metastasis are tightly involved in the proliferation, migration and invasion in cancer. This study aimed to investigate the role of tescalcin (TESC) in the proliferation, migration and invasion of PTMC.

Methods

The expressions of TESC in PTMC tissues and cells were detected by immunohistochemistry or qRT-PCR. Then, TPC-1 and BHT101 cells transfected with TESC-RNAi were used for the transcriptome sequencing. The proliferation, apoptosis, migration and invasion of TPC-1 and BHT101 cells were detected by CCK-8, colony formation, flow cytometric assay, transwell migration and scratch test. Moreover, TESC-RNAi transfected TPC-1 and BHT101 cells were subcutaneously injected into mice. Tumor volume and weight were calculated, and the positive rate of Ki-67 was determined by immunohistochemistry. Finally, the levels of c-Fos, ERK1/2 and p-ERK1/2 were determined by western blot.

Results

The expressions of TESC in PTMC tissues and cell lines were prominently enhanced. Transcriptome sequencing results showed that c-Fos was decreased in TPC-1 and BHT101 cells transfected with TESC-RNAi, which was associated with multiple different signaling pathways including the MAPK signaling pathway. Furthermore, TESC promoted the progress of PTMC by regulating the expression of c-Fos, which might be associated with the ERK signaling pathway.

Conclusions

TESC promoted the growth and metastasis of PTMC through regulating c-Fos/ERK1/2.

Long non-coding ROR promotes the progression of papillary thyroid carcinoma through regulation of the TESC/ALDH1A1/TUBB3/PTEN axis

Papillary thyroidal carcinoma (PTC) is a common endocrine cancer that plagues people across the world. The potential roles of long non-coding RNAs (lncRNAs) in PTC have gained increasing attention. In this study, we aimed to explore whether lncRNA ROR affects the progression of PTC, with the involvement of tescalcin (TESC)/aldehyde dehydrogenase isoform 1A1 (ALDH1A1)/βIII-tubulin (TUBB3)/tensin homolog (PTEN) axis. PTC tumor and adjacent tissues were obtained, followed by measurement of lncRNA ROR and TESC, ALDH1A1, and TUBB3 expression. Interactions among lncRNA ROR, TESC, ALDH1A1, TUBB3, and PTEN were evaluated by ChIP assay, RT-qPCR, or western blot analysis. After ectopic expression and depletion experiments in PTC cells, MTT and colony formation assay, Transwell assay, and flow cytometry were performed to detect cell viability and colony formation, cell migration and invasion, and apoptosis, respectively. In addition, xenograft in nude mice was performed to test the effects of lncRNA ROR and PTEN on tumor growth in PTC in vivo. LncRNA ROR, TESC, ALDH1A1, and TUBB3 were highly expressed in PTC tissues and cells. Overexpression of lncRNA ROR activated TESC by inhibiting the G9a recruitment on the promoter of TESC and histone H3-lysine 9me methylation. Moreover, TESC upregulated ALDH1A1 expression to increase TUBB3 expression, which then reduced PTEN expression. Overexpression of lncRNA ROR, TESC, ALDH1A1 or TUBB3 and silencing of PTEN promoted PTC cell viability, colony formation, migration, and invasion while suppressing apoptosis. Moreover, overexpression of lncRNA ROR increased tumor growth by inhibiting PTEN in vivo. Taken together, the current study demonstrated that lncRNA ROR mediated TESC/ALDH1A1/TUBB3/PTEN axis, thereby facilitating the development of PTC.

Construction of a Pearson- and MIC-Based Co-expression Network to Identify Potential Cancer Genes

The weighted gene co-expression network analysis (WGCNA) method constructs co-expressed gene modules based on the linear similarity between paired gene expressions. Linear correlations are the main form of similarity between genes, however, nonlinear correlations still existed and had always been ignored. We proposed a modified network analysis method, WGCNA-P + M, which combines Pearson's correlation coefficient and the maximum information coefficient (MIC) as the similarity measures to assess the linear and nonlinear correlations between genes, respectively. Taking two real datasets, GSE44861 and liver hepatocellular carcinoma (TCGA-LIHC), as examples, we compared the gene modules constructed by WGCNA-P + M and WGCNA from four perspectives: the "Usefulness" score, GO enrichment analysis on genes in the gray module, prediction performance of the top hub gene, survival analysis and literature reports on different hub genes. The results showed that the modules obtained by WGCNA-P + M are more biological meaningful, the hub genes obtained from WGCNA-P + M have more potential cancer genes.

Long non-coding RNA TUG1/microRNA-187-3p/TESC axis modulates progression of pituitary adenoma via regulating the NF-κB signaling pathway

The molecule mechanisms of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in human diseases have been broadly studied recently, therefore, our research aimed to assess the effect of lncRNA taurine upregulated gene 1 (TUG1)/miR-187-3p/tescalcin (TESC) axis in pituitary adenoma (PA) by regulating the nuclear factor-kappa B (NF-κB) signaling pathway. We observed that TUG1 was upregulated in PA tissues and was associated with invasion, knosp grade and tumor size. TUG1 particularly bound to miR-187-3p. TUG1 knockdown inhibited cell proliferation, invasion, migration, and epithelial–mesenchymal transition, promoted apoptosis, and regulated the expression of NF-κB p65 and inhibitor of κB (IκB)-α in PA cells lines in vitro, and also inhibited tumor growth in vivo, and these effects were reversed by miR-187-3p reduction. Similarly, miR-187-3p elevation inhibited PA cell malignant behaviors and modulated the expression of NF-κB p65 and IκB-α in PA cells, and reduced in vivo tumor growth as well. TUG1 inhibition downregulated TESC, which was targeted by miR-187-3p. In conclusion, this study suggests that TUG1 sponges miR-187-3p to affect PA development by elevating TESC and regulating the NF-κB signaling pathway.

ErBb Family Proteins in Cholangiocarcinoma and Clinical Implications

The erythroblastic leukemia viral oncogene homolog (ErBb) family consists of the receptor tyrosine kinases (RTK) epidermal growth factor receptor (EGFR; also called ERBB1), ERBB2, ERBB3, and ERBB4. This family is closely associated with the progression of cholangiocarcinoma (CC) through the regulation of cellular networks, which are enhanced during tumorigenesis, metastasis, and chemoresistance. Additionally, the constitutive activation of cellular signaling by the overexpression and somatic mutation-mediated alterations conferred by the ErBb family on cholangiocarcinoma and other cancers enhances tumor aggressiveness and chemoresistance by contributing to the tumor microenvironment. This review summarizes the recent findings on the molecular functions of the ErBb family and their mutations during the progression of cholangiocarcinoma. It also discusses the developments and applications of various devising strategies for targeting the ErBb family through different inhibitors in various stages of clinical trials, which are essential for improving targeted clinical therapies.

Tescalcin is an unfavorable prognosis factor that regulats cell proliferation and survival in hepatocellular carcinoma patients

Background

Hepatocellular carcinoma (HCC) is a major health problem and a primary cause of cancer‐related death worldwide. Although great advances have achieved recently by large‐scale high‐throughput analysis, the precise molecular mechanism underlying HCC progression remains to be clearly elucidated. We investigated the relationship between Tescalcin (TESC), a candidate oncogene, and clinicopathological features of HCC patients and explored the role of TECS in HCC development.

Methods

To identify new genes involved in HCC development, we analyzed The Cancer Genome Atlas liver cancer database, and TESC was selected for further investigation. HCC tissue microarray analysis for TESC and its association with clinicopathological features were performed to investigate its clinical significance. TESC was knocked down by using short‐hairpin RNAs. Cell proliferation was analyzed by WST‐1 assay and cell counting. Cell apoptosis was tested by fluorescence‐activated cell sorting. A subcutaneous xenograft tumor model in nude mice was established to determine the in vivo function of TESC. Affymetrix microarray was used to identify its molecular mechanism.

Results

TESC was significantly increased in HCC tissues compared with the adjacent normal liver tissues. High expression of TESC was detected in 61 of 172 HCC patients by tissue microarray. Large tumor (> 5 cm) and elevated total bilirubin were associated with high TESC expression (both P < 0.050). In multivariate analysis, TESC was identified as an independent prognostic factor for short overall survival of HCC patients. TESC knockdown impaired HCC cell growth in vitro and in vivo. TESC knockdown significantly increased cell apoptosis in HCC cell lines. Furthermore, Affymetrix microarray analysis revealed that TESC knockdown inhibited tumor proliferation‐related pathways while activated cell death‐related pathways.

Conclusion

TESC was identified as an independent prognostic factor for short overall survival of HCC patients, and was critical for HCC cell proliferation and survival.

TESC Promotes TGF-α/EGFR-FOXM1-Mediated Tumor Progression in Cholangiocarcinoma

Cholangiocarcinoma is a relatively uncommon but highly lethal malignancy. Improving outcomes in patients depends on earlier diagnosis and appropriate treatment; however, no satisfactory diagnostic biomarkers or targeted therapies are currently available. To address this shortcoming, we analyzed the transcriptomic datasets of cholangiocarcinoma from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases and found that TESC is highly expressed in cholangiocarcinoma. Elevated cellular levels of TESC are correlated with larger tumor size and predict a poor survival outcome for patients. Knockdown of TESC via RNA interference suppresses tumor growth. RNA-sequencing analysis showed that silencing of TESC decreases the level of FOXM1, leading to cell cycle arrest. Correlation analysis revealed that the cellular level of TESC is correlated with that of FOXM1 in cholangiocarcinoma patients. We further observed that upon TGF-α induction, TESC is upregulated through the EGFR-STAT3 pathway and mediates TGF-α-induced tumor cell proliferation. In vivo experiments revealed that knockdown of TESC significantly attenuates tumor cell growth. Therefore, our data provide novel insight into TESC-mediated oncogenesis and reveal that TESC is a potential biomarker or serves as a therapeutic target for cholangiocarcinoma.

Ca2+-Binding Proteins of the EF-Hand Superfamily: Diagnostic and Prognostic Biomarkers and Novel Therapeutic Targets

A multitude of Ca²⁺-sensor proteins containing the specific Ca²⁺-binding motif (helix-loop-helix, called EF-hand) are of major clinical relevance in a many human diseases. Measurements of troponin, the first intracellular Ca-sensor protein to be discovered, is nowadays the "gold standard" in the diagnosis of patients with acute coronary syndrome (ACS). Mutations have been identified in calmodulin and linked to inherited ventricular tachycardia and in patients affected by severe cardiac arrhythmias. Parvalbumin, when introduced into the diseased heart by gene therapy to increase contraction and relaxation speed, is considered to be a novel therapeutic strategy to combat heart failure. S100 proteins, the largest subgroup with the EF-hand protein family, are closely associated with cardiovascular diseases, various types of cancer, inflammation, and autoimmune pathologies. The intention of this review is to summarize the clinical importance of this protein family and their use as biomarkers and potential drug targets, which could help to improve the diagnosis of human diseases and identification of more selective therapeutic interventions.

Suppression of Tescalcin inhibits growth and metastasis in renal cell carcinoma via downregulating NHE1 and NF-kB signaling

BACKGROUND

Renal cell carcinoma (RCC) is the most common form of kidney cancer. Recent studies reported that Tescalcin was overexpressed in various tumor types. However, the status of Tescalcin protein expression in RCC and its biological function is uncertain. This study was designed to investigate the expression of Tescalcin in human RCC and its biological function.

METHODS

shRNA transfection was performed to abrogates the expression of Tescalcin. Quantitative real time PCR and western blotting assays were used to determine mRNA and protein expression levels, respectively. The cell viability was analyzed by MTT and colony formation. Cell flow cytometry was used to assess pHi value and cell apoptosis. Cell invasive and migratory ability was measured with modified Boyden chamber assay. Xenograft model was setup to evaluate tumor growth.

RESULTS

Tescalcin was overexpressed in RCC tissues compared with matched normal tissues. It was also overexpressed in RCC cell lines relative that of normal cells. Suppression Tescalcin with specific shRNA resulted in the inhibition of cell proliferation, migration, invasion and apoptosis of RCC cells. Additionally, silencing of Tescalcin also caused the inhibition of the tumor growth in nude mice. Mechanistic study showed that Tescalcin regulated cell proliferation, migration and invasion via NHE1/pHi axis as well as AKT/NF-κB signaling pathway.

CONCLUSIONS

These findings demonstrate that atopic expression of Tescalcin facilitates the survival, migration and invasion of RCC cells via NHE1/pHi axis as well as AKT/ NF-κB signaling pathway, providing new perspectives for the future study of Tescalcin as a therapeutic target for RCC.

The oncogene KRAS promotes cancer cell dissemination by stabilizing spheroid formation via the MEK pathway

Background

Peritoneal dissemination is a critical prognostic factor in ovarian cancer. Although stabilized spheroid formation promotes cancer cell peritoneal dissemination in ovarian cancer, the associated oncogenes are unknown. In this study, we assessed the role of the KRAS oncogene in ovarian cancer cell dissemination, focusing on the stability of cells in spheroid condition, as well as the modulation of intracellular signaling following spheroid transformation.

Methods

We used ID8, a murine ovarian cancer cell line, and ID8-KRAS, an oncogenic KRAS (G12 V)-transduced ID8 cell line in this study. Spheroid-forming (3D) culture and cell proliferation assays were performed to evaluate the growth characteristics of these cells. cDNA microarray analysis was performed to identify genes involved in KRAS-associated signal transduction in floating condition. A MEK inhibitor was used to evaluate the effect on cancer peritoneal dissemination.

Results

Cell viability and proliferation in monolayer (2D) cultures did not differ between ID8 and ID8-KRAS cells. However, the proportions of viable and proliferating ID8-KRAS cells in 3D culture were approximately 2-fold and 5-fold higher than that of ID8, respectively. Spheroid-formation was increased in ID8-KRAS cells. Analysis of peritoneal floating cells obtained from mice intra-peritoneally injected with cancer cells revealed that the proportion of proliferating cancer cells was approximately 2-fold higher with ID8-KRAS than with ID8 cells. Comprehensive cDNA microarray analysis revealed that pathways related to cell proliferation, and cell cycle checkpoint and regulation were upregulated specifically in ID8-KRAS cells in 3D culture, and that some genes partially regulated by the MEK-ERK pathway were upregulated only in ID8-KRAS cells in 3D culture. Furthermore, a MEK inhibitor, trametinib, suppressed spheroid formation in 3D culture of ID8-KRAS cells, although trametinib did not affect 2D-culture cell proliferation. Finally, we demonstrated that trametinib dramatically improved the prognosis for mice with ID8-KRAS tumors in an in vivo mouse model.

Conclusions

Our data indicated that KRAS promoted ovarian cancer dissemination by stabilizing spheroid formation and that the MEK pathway is important for stabilized spheroid formation. Disruption of spheroid formation by a MEK inhibitor could be a therapeutic target for cancer peritoneal dissemination.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4922-4) contains supplementary material, which is available to authorized users.

Calcineurin B homologous protein 3 binds with high affinity to the CHP binding domain of the human sodium/proton exchanger NHE1

The Na+/H+ exchanger NHE1 is critical for cell vitality as it controls intracellular pH and cell volume. Its functionality is influenced by calcineurin B homologous proteins (CHPs). The human isoform CHP3 is important for transport of NHE1 to the plasma membrane and for its activity. Here, we characterized the binding interaction of human CHP3 with the regulatory domain of NHE1. The exact binding site of CHP3 was previously debated. CHP3 as well as both regions of NHE1 in question were produced and purified. CHP3 specifically formed stable complexes with the CHP-binding region (CBD) of NHE1 (residues 503-545) in size-exclusion chromatography (SEC), but not with the C-terminal region (CTD, residues 633-815). CTD was functional as shown by Ca2+-dependent binding of calmodulin in SEC analysis. CHP3 bound with high affinity to CBD with an equilibrium dissociation constant (KD) of 56 nM determined by microscale thermophoresis. The high affinity was substantiated by isothermal calorimetry analysis (KD = 3 nM), which also revealed that the interaction with CBD is strongly exothermic (ΔG° = -48.6 kJ/mol, ΔH = -75.3 kJ/mol, -TΔS° = 26.7 kJ/mol). The data provide insights in the molecular mechanisms that underlie the regulatory interaction of CHP3 and NHE1 and more general of calcineurin homologous proteins with their target proteins.

Tescalcin/c-Src/IGF1Rβ-mediated STAT3 activation enhances cancer stemness and radioresistant properties through ALDH1

Tescalcin (TESC; also known as calcineurin B homologous protein 3, CHP3) has recently reported as a regulator of cancer progression. Here, we showed that the elevation of TESC in non-small cell lung cancer (NSCLC) intensifies epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties, consequently enhancing the cellular resistance to γ-radiation. TESC expression and the phosphorylation (consequent activation) of signal transducer and activator of transcription 3 (STAT3) were upregulated in CSC-like ALDH1^high cells than in ALDH1^low cells sorted from A549 NSCLC cells. Knockdown of TESC suppressed CSC-like properties as well as STAT3 activation through inhibition of insulin-like growth factor 1 receptor (IGF1R), a major signaling pathway of lung cancer stem cells. TESC activated IGF1R by the direct recruitment of proto-oncogene tyrosine kinase c-Src (c-Src) to IGF1Rβ complex. Treatment of IGF1R inhibitor, AG1024, also suppressed c-Src activation, implicating that TESC mediates the mutual activation of c-Src and IGF1R. STAT3 activation by TESC/c-Src/IGF1R signaling pathway subsequently upregulated ALDH1 expression, which enhanced EMT-associated CSC-like properties. Chromatin immunoprecipitation and luciferase assay demonstrated that STAT3 is a potential transcription activator of ALDH1 isozymes. Ultimately, targeting TESC can be a potential strategy to overcome therapeutic resistance in NSCLC caused by augmented EMT and self-renewal capacity.

Differential preventive activity of sulindac and atorvastatin in Apc+/Min-FCCCmice with or without colorectal adenomas

OBJECTIVE

The response of subjects to preventive intervention is heterogeneous. The goal of this study was to determine if the efficacy of a chemopreventive agent differs in non-tumour-bearing animals versus those with colorectal tumours. Sulindac and/or atorvastatin was administered to Apc^+/Min-FCCC mice with known tumour-bearing status at treatment initiation.

DESIGN

Male mice (6-8 weeks old) underwent colonoscopy and received control chow or chow with sulindac (300 ppm), atorvastatin (100 ppm) or sulindac/atorvastatin. Tissues were collected from mice treated for 14 weeks (histopathology) or 7 days (gene expression). Cell cycle analyses were performed on SW480 colon carcinoma cells treated with sulindac, atorvastatin or both.

RESULTS

The multiplicity of colorectal adenomas in untreated mice bearing tumours at baseline was 3.6-fold higher than that of mice that were tumour free at baseline (P=0.002). Atorvastatin completely inhibited the formation of microadenomas in mice that were tumour free at baseline (P=0.018) and altered the expression of genes associated with stem/progenitor cells. Treatment of tumour-bearing mice with sulindac/atorvastatin led to a 43% reduction in the multiplicity of colorectal adenomas versus untreated tumour-bearing mice (P=0.049). Sulindac/atorvastatin increased the expression of Hoxb13 and Rprm significantly, suggesting the importance of cell cycle regulation in tumour inhibition. Treatment of SW480 cells with sulindac/atorvastatin led to cell cycle arrest (G0/G1).

CONCLUSIONS

The tumour status of animals at treatment initiation dictates response to therapeutic intervention. Atorvastatin eliminated microadenomas in tumour-free mice. The tumour inhibition observed with Sul/Atorva in tumour-bearing mice was greater than that achieved with each agent.

Dehydropeptidase 1 promotes metastasis through regulation of E-cadherin expression in colon cancer

Dehydropeptidase 1 (DPEP1) is a zinc-dependent metalloproteinase that is expressed aberrantly in several cancers. The role of DPEP1 in cancer remain controversial. In this study, we demonstrate that DPEP1 functions as a positive regulator for colon cancer cell metastasis. The expression of DPEP1 mRNA and proteins were upregulated in colon cancer tissues compared to normal mucosa. Gain-of-function and loss-of-function approaches were used to examine the malignant phenotype of DPEP1-expressing or DPEP1-depleted cells. DPEP1 expression caused a significant increase in colon cancer cell adhesion and invasion in vitro, and metastasis in vivo. In contrast, DPEP1 depletion induced opposite effects. Furthermore, cilastatin, a DPEP1 inhibitor, suppressed the invasion and metastasis of DPEP1-expressing cells. DPEP1 inhibited the leukotriene D4 signaling pathway and increased the expression of E-cadherin. We also show that DPEP1 mediates TGF-β-induced EMT. TGF-β transcriptionally repressed DPEP1 expression. TGF-β treatment decreased E-cadherin expression and promoted cell invasion in DPEP1-expressing colon cancer cell lines, whereas it did not affect these parameters in DPEP1-depleted cell lines. These results suggest that DPEP1 promotes cancer metastasis by regulating E-cadherin plasticity and that it might be a potential therapeutic target for preventing the progression of colon cancer.

Emerging roles of the single EF-hand Ca2+ sensor tescalcin in the regulation of gene expression, cell growth and differentiation

Tescalcin (TESC, also known as calcineurin-homologous protein 3, CHP3) is a 24-kDa EF-hand Ca²⁺-binding protein that has recently emerged as a regulator of cell differentiation and growth. The TESC gene has also been linked to human brain abnormalities, and high expression of tescalcin has been found in several cancers. The expression level of tescalcin changes dramatically during development and upon signal-induced cell differentiation. Recent studies have shown that tescalcin is not only subjected to up- or down-regulation, but also has an active role in pathways that drive cell growth and differentiation programs. At the molecular level, there is compelling experimental evidence showing that tescalcin can directly interact with and regulate the activities of the Na⁺/H⁺ exchanger NHE1, subunit 4 of the COP9 signalosome (CSN4) and protein kinase glycogen-synthase kinase 3 (GSK3). In hematopoetic precursor cells, tescalcin has been shown to couple activation of the extracellular signal-regulated kinase (ERK) cascade to the expression of transcription factors that control cell differentiation. The purpose of this Commentary is to summarize recent efforts that have served to characterize the biochemical, genetic and physiological attributes of tescalcin, and its unique role in the regulation of various cellular functions.

TET-catalyzed 5-hydroxymethylcytosine regulates gene expression in differentiating colonocytes and colon cancer

The formation of differentiated cell types from pluripotent progenitors involves epigenetic regulation of gene expression. DNA hydroxymethylation results from the enzymatic oxidation of 5-methylcytosine (5-mC) to 5-hydroxymethylcytosine (5-hmC) by the ten-eleven translocation (TET) 5-mC dioxygenase enzymes. Previous work has mapped changes in 5-mC during differentiation of intestinal stem cells. However, whether or not 5-hmC regulates colonocyte differentiation is unknown. Here we show that 5-hmC regulates gene expression during colonocyte differentiation and controls gene expression in human colon cancers. Genome-wide profiling of 5-hmC during in vitro colonic differentiation demonstrated that 5-hmC is gained at highly expressed and induced genes and is associated with intestinal transcription factor binding sites, including those for HNF4A and CDX2. TET1 induction occurred during differentiation, and TET1 knockdown altered gene expression and inhibited barrier formation of colonocytes. We find that the 5-hmC distribution in primary human colonocytes parallels the distribution found in differentiated cells in vitro, and that gene-specific 5-hmC changes in human colon cancers are directly correlated with changes in gene expression. Our results support a model in which 5-hmC regulates differentiation of adult human intestine and 5-hmC alterations contribute to the disrupted gene expression in colon cancer.

Prognostic significance of Traf2- and Nck- interacting kinase (TNIK) in colorectal cancer

BACKGROUND

The potential of expression profiling using microarray analysis as a tool to predict the prognosis for different types of cancer has been realized. This study aimed to identify a novel biomarker for colorectal cancer (CRC).

METHODS

The expression profiles of cancer cells in 152 patients with stage I-III CRC were examined using microarray analysis. High expression in CRC cells, especially in patients with distant recurrences, was a prerequisite to select candidate genes. Thus, we identified seventeen candidate genes, and selected Traf2- and Nck-interacting kinase (TNIK), which was known to be associated with progression in CRC through Wnt signaling pathways. We analyzed the protein expression of TNIK using immunohistochemistry (IHC) and investigated the relationship between protein expression and patient characteristics in 220 stage I-III CRC patients.

RESULTS

Relapse-free survival was significantly worse in the TNIK high expression group than in the TNIK low expression group in stage II (p = 0.028) and stage III (p = 0.006) patients. In multivariate analysis, high TNIK expression was identified as a significant independent risk factor of distant recurrence in stage III patients.

CONCLUSION

This study is the first to demonstrate the prognostic significance of intratumoral TNIK protein expression in clinical tissue samples of CRC, in that high expression of TNIK protein in primary tumors was associated with distant recurrence in stage II and III CRC patients. This TNIK IHC study might contribute to practical decision-making in the treatment of these patients.