Cytokeratin immunoexpression in esophageal squamous cell carcinoma of high-risk population in Northeast India

Interception of Signaling Circuits of Esophageal Adenocarcinoma Cells by Resveratrol Reveals Molecular and Immunomodulatory Signatures

Simple Summary

Adenocarcinoma of the esophagus has been on the rise lately. Increase in mortality due to a paucity of efficacious drugs for this cancer prompted us to discover molecular signatures to combat this malady. To this end, we chose resveratrol—a polyphenol and studied its impact on three esophageal adenocarcinoma cell lines (OE33, OE19 and FLO-1) by multilevel profiling. Here, we show the impact of resveratrol on the viability of the three cell systems studied, at the cellular, molecular level and by proteomic analysis. Impact on programmed cell death pathway resulting in an increase in apoptotic and caspase-positive cells were observed. Decrease in Bcl2. levels and impact on reactive oxygen species (ROS) was also observed. Moreover, proteomic profiling highlighted pivotal differentially regulated signaling molecules. Notably, the downregulation of Ku80 by resveratrol could be harnessed for chemo-radiation therapy to prevent DNA break repair after radiation therapy. Additionally, protein profiling has shed light on molecular and immune-modulatory signatures with implications for discovering novel treatments such as chemo-immunotherapy.

Abstract

Deregulation of signaling pathways due to mutations sets the cell on a path to neoplasia. Therefore, recent reports of increased mutations observed in esophageal tissue reflects the enhanced risk of tumor formation. In fact, adenocarcinoma of the esophagus has been on the rise lately. Increase in mortality due to a paucity of efficacious drugs for this cancer prompted us to discover molecular signatures to combat this malady. To this end, we chose resveratrol—a polyphenol with anticancer property—and studied its impact on three esophageal adenocarcinoma cell lines (OE33, OE19 and FLO-1) by multilevel profiling. Here, we show the impact of resveratrol on the viability of the three adenocarcinoma esophageal cell systems studied, at the cellular level. Furthermore, an analysis at the molecular level revealed that the action was through the programmed cell death pathway, resulting in an increase in apoptotic and caspase-positive cells. The impact on reactive oxygen species (ROS) and a decrease in Bcl2 levels were also observed. Moreover, proteomic profiling highlighted pivotal differentially regulated signaling molecules. The phenotypic effect observed in resveratrol-treated esophageal cells could be due to the stoichiometry per se of the fold changes observed in entities of key signaling pathways. Notably, the downregulation of Ku80 and other pivotal entities by resveratrol could be harnessed for chemo-radiation therapy to prevent DNA break repair after radiation therapy. Additionally, multilevel profiling has shed light on molecular and immune-modulatory signatures with implications for discovering novel treatments, including chemo-immunotherapy, for esophageal adenocarcinomas which are known to be aggressive cancers.

Keratin intermediate filaments in the colon: guardians of epithelial homeostasis

Keratin intermediate filament proteins are major cytoskeletal components of the mammalian simple layered columnar epithelium in the gastrointestinal tract. Human colon crypt epithelial cells express keratins 18, 19 and 20 as the major type I keratins, and keratin 8 as the type II keratin. Keratin expression patterns vary between species, and mouse colonocytes express keratin 7 as a second type II keratin. Colonic keratin patterns change during cell differentiation, such that K20 increases in the more differentiated crypt cells closer to the central lumen. Keratins provide a structural and mechanical scaffold to support cellular stability, integrity and stress protection in this rapidly regenerating tissue. They participate in central colonocyte processes including barrier function, ion transport, differentiation, proliferation and inflammatory signaling. The cell-specific keratin compositions in different epithelial tissues has allowed for the utilization of keratin-based diagnostic methods. Since the keratin expression pattern in tumors often resembles that in the primary tissue, it can be used to recognize metastases of colonic origin. This review focuses on recent findings on the biological functions of mammalian colon epithelial keratins obtained from pivotal in vivo models. We also discuss the diagnostic value of keratins in chronic colonic disease and known keratin alterations in colon pathologies. This review describes the biochemical properties of keratins and their molecular actions in colonic epithelial cells and highlights diagnostic data in colorectal cancer and inflammatory bowel disease patients, which may facilitate the recognition of disease subtypes and the establishment of personal therapies in the future.

MEIS1 knockdown may promote differentiation of esophageal squamous carcinoma cell line KYSE-30

Background

MEIS1 (Myeloid ecotropic viral integration site 1), as a homeobox (HOX) transcription factor, has a dual function in different types of cancer. Although numerous roles are proposed for MEIS1 in differentiation, stem cell function, gastrointestinal development and tumorigenesis, the involved molecular mechanisms are poor understood. Our aim in this study was to elucidate the functional correlation between MEIS1, as regulator of differentiation process, and the involved genes in cell differentiation in human esophageal squamous carcinoma (ESC) cell line KYSE‐30.

Methods

The KYSE‐30 cells were transduced using recombinant retroviral particles containing specific shRNA sequence against MEIS1 to knockdown MEIS1 gene expression. Following RNA extraction and cDNA synthesis, mRNA expression of MEIS1 and the selected genes including TWIST1, EGF, CDX2, and KRT4 was examined using relative comparative real‐time PCR.

Results

Retroviral transduction caused a significant underexpression of MEIS1 in GFP‐hMEIS1 compared to control GFP cells approximately 5.5‐fold. While knockdown of MEIS1 expression caused a significant decrease in EGF and TWIST1 mRNA expression, nearly ‐8‐ and ‐12‐fold respectively, it caused a significant increase in mRNA expression of differentiation markers including KRT4 and CDX2, approximately 34‐ and 1.14‐fold, correspondingly.

Conclusion

MEIS1 gene silencing in KYSE‐30 cells increased expression of epithelial markers and decreased expression of epithelial‐mesenchymal transition (EMT) marker TWIST1. It may highlight the role of MEIS1 in differentiation process of KYSE‐30 cells. These results may confirm that MEIS1 silencing promotes differentiation and decreases EMT capability of ESC cell line KYSE‐30.

Syringic acid may attenuate the oral mucosal carcinogenesis via improving cell surface glycoconjugation and modifying cytokeratin expression

Syringic acid (SRA) is an excellent anti-oxidant and anti-cancer property in various in vitro and in vivo studies. In the present study was modifying effect of SRA on 7,12-dimethylbenz(a)anthracene (DMBA) induced cell surface glycoconjugates (GCs) abnormalities in the plasma and buccal mucosa of golden Syrian hamster buccal pouch carcinogenesis (HBPCs). Topical application of DMBA three times a week for 10 weeks on the buccal pouches of the hamsters resulted in well developed squamous cell carcinoma. GCs status was assessed biochemically, histological and immunoexpression pattern of cytokeratin (CK) in the buccal mucosa of the DMBA treated hamsters. Elevated levels of GCs and CK expression were observed in DMBA alone treated hamsters. Oral pre-administration of SRA (50 mg/kg bw) positively modulates the GCs levels and CK expressions to near normal. The present findings suggested that SRA can protect cell surface GCs and CK expression during DMBA induced HBPCs.

p120-catenin down-regulation and epidermal growth factor receptor overexpression results in a transformed epithelium that mimics esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is an aggressive malignancy with a poor prognosis due to its highly invasive and metastatic potential. The molecular pathogenesis underlying the invasive mechanism of ESCC is not well known because of the lack of existing models to study this disease. p120-Catenin (p120ctn) and the epidermal growth factor receptor (EGFR) have each been implicated in several cancers, including ESCC. p120ctn is down-regulated in 60% of ESCC tumors, whereas EGFR is the most commonly overexpressed oncogene in ESCC. For these reasons, we investigated the cooperation between p120ctn and EGFR and its effect on ESCC invasion. We show that p120ctn down-regulation is commonly associated with EGFR overexpression. By using a three-dimensional culture system, we demonstrate that the inverse relationship between p120ctn and EGFR has biological implications. Specifically, p120ctn down-regulation coupled with EGFR overexpression in human esophageal keratinocytes (EPC1-PE) was required to promote invasion. Morphological comparison of EPC1-PE cells grown in three-dimensional culture and human ESCC revealed identical features, including significantly increased cellularity, nuclear grade, and proliferation. Molecular characteristics were measured by keratin expression patterns, which were nearly identical between EPC1-PE cells in three-dimensional culture and ESCC samples. Altogether, our analyses have demonstrated that p120ctn down-regulation and EGFR overexpression are able to mimic human ESCC in a relevant three-dimensional culture model.

Status of epigenetic chromatin modification enzymes and esophageal squamous cell carcinoma risk in northeast Indian population

Esophageal cancer incidence is reported in high frequency in northeast India. The etiology is different from other population at India due to wide variations in dietary habits or nutritional factors, tobacco/betel quid chewing and alcohol habits. Since DNA methylation, histone modification and miRNA-mediated epigenetic processes alter the gene expression, the involvement of these processes might be useful to find out epigenetic markers of esophageal cancer risk in northeast Indian population. The present investigation was aimed to carryout differential expression profiling of chromatin modification enzymes in tumor and normal tissue collected from esophageal squamous cell carcinoma (ESCC) patients. Differential mRNA expression profiling and their validation was done by quantitative real time PCR and tissue microarray respectively. Univariate and multiple logistic regression analysis were used to analyze the epidemiological data. mRNA expression data was analyzed by Student t-test. Fisher exact test was used for tissue microarray data analysis. Higher expression of enzymes regulating methylation (DOT1L and PRMT1) and acetylation (KAT7, KAT8, KAT2A and KAT6A) of histone was found associated with ESCC risk. Tissue microarray done in independent cohort of 75 patients revealed higher nuclear protein expression of KAT8 and PRMT1 in tumor similar to mRNA expression. Expression status of PRMT1 and KAT8 was found declined as we move from low grade to high grade tumor. Betel nut chewing, alcohol drinking and dried fish intake were significantly associated with increased risk of esophageal cancer among the study subject. Study suggests the association of PRMT1 and KAT8 with esophageal cancer risk and its involvement in the transition process of low to high grade tumor formation. The study exposes the differential status of chromatin modification enzymes between tumor and normal tissue and points out that relaxed state of chromatin facilitates more transcriptionally active genome in esophageal carcinogenesis.

From plasminogen to plasmin: role of plasminogen receptors in human cancer

Cell surface-associated proteolysis mediated by plasmin (PLA) is an essential feature of wound healing, angiogenesis and cell invasion, processes that are dysregulated in cancer development, progression and systemic spread. The generation of PLA, initiated by the binding of its precursor plasminogen (PLG) to the cell surface, is regulated by an array of activators, inhibitors and receptors. In this review, we will highlight the importance of the best-characterized components of the PLG/PLA cascade in the pathogenesis of cancer focusing on the role of the cell surface-PLG receptors (PLG-R). PLG-R overexpression has been associated with poor prognosis of cancer patients and resistance to chemotherapy. We will also discuss recent findings on the molecular mechanisms regulating cell surface expression and distribution of PLG-R.

Evaluation of Bronchiolar and Alveolar Cell Injuries Induced by Short- and Long-term Exposure to Sidestream Smoke

Background

We investigated effects of short- and long-term exposure to sidestream smoke on the bronchiolar and alveolar cells in Sprague-Dawley rats.

Methods

Rats were divided into five experimental groups: groups 1, 2, and 3 (1-month exposure to 3, 5, and 7 cigarettes a day, respectively), groups 4 and 5 (3- and 6 month exposure to five cigarettes a day, respectively). We examined the morphologic changes, the expressions of tumor necrosis factor α (TNF-α), tumor growth factor β1 (TGF-β1), interlekin (IL)-1α, IL-1β, Ki-67, and cytokeratin 14 and in situ apoptosis in the bronchiolar and alveolar cells on light microscopy (LM) and electron microscopic (EM) terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining.

Results

LM showed the respiratory bronchiolar dilatation and alveolar wall collapse. In groups 3, 4, and 5, EM showed loss of the cilia and Clara cells with irregular size, more prominent alveolar wall collapse and dilation of alveolar duct than those of groups 1 and 2. Bronchiolar and alveolar cells showed increased expressions of TNF-α and TGF-β in groups 4 and 5. LM and EM TUNEL stains showed increased apoptosis in groups 3, 4, and 5.

Conclusions

Sidestream smoke causes a bronchiolar and alveolar cell injury and the severity correlates strongly the volume and duration of exposure to sidestream smoke.

Differentially Expressed Proteins between Esophageal Squamous Cell Carcinoma and Adjacent Normal Esophageal Tissue

Proteomics was employed to identify the differentially expressed proteins between esophageal squamous cell carcinoma (ESCC) and adjacent normal esophageal tissues. ESCC tissues and adjacent normal tissues were obtained from 10 patients with ESCC and the proteins were extracted and subjected to two-dimensional gel electrophoresis (2-DE). The differentially expressed proteins were identified after image analysis, and matrix assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF-MS) was used to confirm these proteins. Immunohistochemistry was then performed to detect the expressions of HSP27 and ANX1 in ESCC tissues and adjacent normal tissues. A total of 6 differentially expressed proteins were identified by peptide mass fingerprinting, among which SCCA1, KRT4 and ANX1 were down-regulated and TIM1, MnSOD and HSP27 up-regulated in the ESCC. Immunohistochemistry showed HSP27 was highly expressed in the ESCC which, however, had a low expression of ANX1. These findings were consistent with those in proteomics. There were differentially expressed proteins between ESCC and adjacent normal tissues. The investigation of differentially expressed proteins between ESCC and normal esophageal tissue may provide evidence for the molecular pathogenesis of ESCC.

Fascin and CK4 as biomarkers for esophageal squamous cell carcinoma

BACKGROUND

Several studies have suggested that fascin, cytokeratin 14 and cytokeratin 4 may have significant roles as biomarkers for the progression and survival of esophageal squamous cell carcinoma (ESCC).

MATERIALS AND METHODS

This study performed immunohistochemistry in tissue microarrays, profiling premalignant lesions and invasive tumors.

RESULTS

Fascin increased across the following states as follows: normal-appearing epithelium (26%) to dysplasia (46%) to ESCC (68%), while CK4 was undetectable in ESCC (0%) compared to normal-appearing epithelium (45%) or dysplasia (41%). CK14 was elevated and invariant in expression. In regression analyses, compared to normal-appearing epithelium, higher fascin expression was associated with a 36% increased risk of dysplasia (odds ratio=1.36) and a 56% increased risk of invasive ESCC (odds ratio=1.56).

CONCLUSION

Expression of fascin is up-regulated in the transformation from normal-appearing epithelium, through dysplasia, into invasive carcinoma. Expression of CK4, CK14 and fascin did not correlate with patient survival. Fascin has a potential role as an early detection biomarker and CK4 as a tumor marker in ESCC.

Association between expression of embryonic lethal abnormal vision-like protein HuR and cyclooxygenase-2 in oral squamous cell carcinoma

BACKGROUND

Increased cytoplasmic HuR expression has been noted in several cancer types, where it may contribute to the increased cyclooxygenase-2 (COX-2) expression observed during tumorigenesis and metastasis.

METHODS

To assess the correlation between COX-2 and HuR in oral squamous cell carcinoma (OSCC), the expression patterns of HuR and COX-2 were assessed via immunohistochemistry analyses of 103 OSCC samples.

RESULTS

Cytoplasmic HuR expression was significantly associated with COX-2 expression (p < .025) and lymph node metastasis (p < .050) and distant metastasis (p < .025). In multivariate analysis, cytoplasmic HuR expression was identified as an independent prognostic parameter for reduced overall survival. The inhibition of HuR expression by siRNA or leptomycin B (LMB) caused a reduction in the inducibility of COX-2 in oral cancer cells.

CONCLUSION

Our results indicate that the cytoplasmic expression of HuR is associated with COX-2 expression in OSCCs and HuR can regulate COX-2 expression in oral cancer cell lines.