Evaluation of human tissue kallikrein-related peptidases 6 and 10 expression in early gastroesophageal adenocarcinoma

circSSPO boosts growth of esophageal squamous cell carcinoma through upregulation of micrRNA-6820-5p-mediated KLK8 and PKD1 expression

Investigation on a competitive endogenous RNA (ceRNA) network attracted lots of attention due its function in cancer regulation. Here, we probed into the possible molecular mechanism of circSSPO/microRNA-6820-5p (miR-6820-5p)/kallikrein-related peptidase 8 (KLK8)/PKD1 network in the esophageal squamous cell carcinoma (ESCC). Following whole-transcriptome sequencing and differential analysis in collected ESCC tissue samples, circRNA-miRNA-mRNA regulatory network affecting ESCC was investigated. After interaction measurement among circSSPO/miR-6820-5p/KLK8/PKD1, their regulatory roles in ESCC cell functions in vitro and xenograft tumor growth and lung metastasis in vivo were analyzed. The bioinformatics prediction and sequencing results screened that circSSPO, miR-6820-5p, KLK8, and PKD1 were associated with ESCC development. In ESCC, miR-6820-5p was expressed at very low levels, while circSSPO, KLK8, and PKD1 were highly expressed. In vitro cell experiments further proved that circSSPO competitively inhibited miR-6820-5p to induce ESCC cell malignant properties. Moreover, knockdown of KLK8 or PKD1 inhibited ESCC cell malignant properties. circSSPO also promoted the tumorigenic and metastasis of ESCC through the upregulation of KLK8 and PKD1 expression in vivo. We found that circSSPO was an oncogenic circRNA that was significantly abundant in ESCC tissues and circSSPO exhibited an oncogenic activity in ESCC by elevating expression of KLK8 and PKD1 through suppressing miR-6820-5p expression.

Zinc Gluconate Induces Potentially Cancer Chemopreventive Activity in Barrett's Esophagus: A Phase 1 Pilot Study

BACKGROUND

Chemopreventive effects of zinc for esophageal cancer have been well documented in animal models. This prospective study explores if a similar, potentially chemopreventive action can be seen in Barrett's esophagus (BE) in humans.

AIMS

To determine if molecular evidence can be obtained potentially indicating zinc's chemopreventive action in Barrett's metaplasia.

METHODS

Patients with a prior BE diagnosis were placed on oral zinc gluconate (14 days of 26.4 mg zinc BID) or a sodium gluconate placebo, prior to their surveillance endoscopy procedure. Biopsies of Barrett's mucosa were then obtained for miRNA and mRNA microarrays, or protein analyses.

RESULTS

Zinc-induced mRNA changes were observed for a large number of transcripts. These included downregulation of transcripts encoding proinflammatory proteins (IL32, IL1β, IL15, IL7R, IL2R, IL15R, IL3R), upregulation of anti-inflammatory mediators (IL1RA), downregulation of transcripts mediating epithelial-to-mesenchymal transition (EMT) (LIF, MYB, LYN, MTA1, SRC, SNAIL1, and TWIST1), and upregulation of transcripts that oppose EMT (BMP7, MTSS1, TRIB3, GRHL1). miRNA arrays showed significant upregulation of seven miRs with tumor suppressor activity (-125b-5P, -132-3P, -548z, -551a, -504, -518, and -34a-5P). Of proteins analyzed by Western blot, increased expression of the pro-apoptotic protein, BAX, and the tight junctional protein, CLAUDIN-7, along with decreased expression of BCL-2 and VEGF-R2 were noteworthy.

CONCLUSIONS

When these mRNA, miRNA, and protein molecular data are considered collectively, a cancer chemopreventive action by zinc in Barrett's metaplasia may be possible for this precancerous esophageal tissue. These results and the extensive prior animal model studies argue for a future prospective clinical trial for this safe, easily-administered, and inexpensive micronutrient, that could determine if a chemopreventive action truly exists.

Ectopic expression of KLK6 in MDA-MB-435 melanoma cells reduces tumorigenicity in vivo

Melanoma is an aggressive form of cancer with poor prognosis therefore, identification of associated pathophysiological mechanisms is imperative towards the development of new therapeutic strategies. The KLK6 is a serine protease normally expressed in the epidermis. Recently, we found that elimination of Klk6 in mice results in enhanced resistance to chemically induced non-melanoma skin cancer. To delineate putative roles of KLK6 in melanoma, the invasive KLK6-non-expressing MDA-MB-435 melanoma cell line was stably transfected with the full-length KLK6 cDNA and expression of the corresponding RNA and protein were confirmed. Interestingly, restoration of KLK6 expression resulted in markedly suppressed growth of primary tumors when orthotopically implanted in SCID mice. Analysis of data retrieved from the human protein atlas revealed that melanomas with high KLK6 expression have a trend for longer survival. Collectively, we suggest that KLK6 inhibits growth of melanomas.

Translational research: Empowering the role of pathologists and cytopathologists

Research activity is in the core essence of pathology. Advancing our understanding of disease pathogenesis translates into better patient care. Because of their unique position, laboratorians are the best to accurately identify, annotate, and classify research specimens. They also are essential for the accurate interpretation of genomic testing. Currently, cytopathologists are moving to the center of patient care through active communication with clinicians and patients. There are certain research areas in which cytopathologists can be pioneers, such as image analysis, morphology research, and genotype-phenotype association studies integrating morphologic and molecular features. Health service utilization research is another domain in which cytopathologists can excel. Successful research is a journey that necessitates multiple steps. It also involves building expertise in how to overcome obstacles and handle challenges.

Kallikrein-related peptidases and associated microRNAs as promising prognostic biomarkers in gastrointestinal malignancies

Gastrointestinal (GI) malignancies represent a wide spectrum of diseases of the GI tract and its accessory digestive organs, including esophageal (EC), gastric (GC), hepatocellular, pancreatic (PC) and colorectal cancers (CRC). Malignancies of the GI system are responsible for nearly 30% of cancer-related morbidity and approximately 40% of cancer-related mortality, worldwide. For this reason, the discovery of novel prognostic biomarkers that can efficiently provide a better prognosis, risk assessment and prediction of treatment response is an imperative need. Human kallikrein-related peptidases (KLKs) are a subgroup of trypsin and chymotrypsin-like serine peptidases that have emerged as promising prognosticators for many human types of cancer, being aberrantly expressed in cancerous tissues. The aberrant expression of KLKs in human malignancies is often regulated by KLK/microRNAs (miRNAs) interactions, as many miRNAs have been found to target KLKs and therefore alter their expression levels. The biomarker utility of KLKs has been elucidated not only in endocrine-related human malignancies, including those of the prostate and breast, but also in GI malignancies. The main purpose of this review is to summarize the existing information regarding the prognostic significance of KLKs in major types of GI malignancies and highlight the regulatory role of miRNAs on the expression levels of KLKs in these types of cancer.

Urinary kallikrein 10 predicts the incurability of gastric cancer

The current imaging modalities are not sufficient to identify inoperable tumor factors, including distant metastasis and local invasion. Hence, we conducted this study using urine samples to discover non-invasive biomarkers for the incurability of gastric cancer (GC). Urine samples from 111 GC patients were analyzed in this study. The GC cohort was categorized and analyzed according to disease stage and operability. In the discovery phase, protease protein array analysis identified 3 potential candidate proteins that were elevated in the urine of advanced GC patients compared to early GC patients. Among them, urinary kallikrein 10 (KLK10) was positively associated with tumor stage progression. Moreover, the urinary level of KLK10 (uKLK10) was significantly elevated in the urine of patients with inoperable GC compared to operable GC patients (median, 118 vs. 229; P=0.014). The combination of uKLK10, tumor location and tumor size distinguished operability of GC with an area under the curve of 0.859, 82.4% sensitivity and 86.2% specificity. Disease-free survival (DFS) was significantly shorter in GC patients with high uKLK10 compared to those with low uKLK10 (hazard ratio: 3.30 [95% confidence interval, 1.58-6.90] P<0.001). Immunohistochemical analyses also demonstrated a positive correlation between tumor stage and KLK10 expression in GC tissues (r=0.426, P<0.001). In addition, GC patients with high expression of pathological KLK10 (pKLK10) showed a significantly shorter DFS compared to those with low pKLK10 (hazard ratio: 3.79 [95% confidence interval, 1.27-11.24] P=0.010). uKLK10 is a promising non-invasive biomarker for the inoperability and incurability of GC.

Strong NFκB Expression is Associated With High-grade Dysplasia in Barrett's Esophagus

Nuclear factor kappa B (NFκB) is a transcription factor that regulates the activation of genes involved in proinflammatory response and growth. In this study, we utilized immunohistochemical stains for 2 of the NFκB molecules (RELA and NFκB-1) to evaluate the expression of NFκB in Barrett's esophagus (BE). Forty-three cases of BE [17 cases with no dysplasia, 16 cases with low-grade dysplasia (LGD), and 10 cases with high-grade dysplasia (HGD)], 10 normal esophageal biopsies, and 9 cases of esophageal adenocarcinoma were evaluated. Expression of NFκB-1 and RELA did not occur in normal esophageal squamous mucosa. BE without dysplasia showed weak expression of RELA and NFκB-1 in 35% and 65% of cases, respectively. BE with LGD showed weak expression of RELA and NFκB-1 in 50% and 75% of cases, respectively. Strong expression of RELA and NFκB-1 did not occur in BE without dysplasia or with LGD. BE with HGD showed strong expression of RELA and NFκB-1 in 80% and 90% of cases, respectively. All cases of adenocarcinoma showed strong expression of both RELA and NFκB-1. There was a progressive increase in staining intensity of RELA and NFκB-1 along the metaplasia-dysplasia-adenocarcinoma pathway. Strong expression of NFκB is associated with HGD and adenocarcinoma (P<0.0001). We showed that strong expression of NFκB-1 and RELA correlates highly with BE with HGD and adenocarcinoma.