Preclinical evaluation of the efficacy of α-Difluoromethylornithine and Sulindac against SARS-CoV-2 infection.

Despite numerous research efforts and several effective vaccines and therapies developed against COronaVIrus Disease 2019 (COVID-19), drug repurposing remains an attractive alternative to identify new treatments for SARS-CoV-2 virus variants and other viral infections that may emerge in the future. Cellular polyamines support viral propagation and tumor growth. Here we tested the antiviral activity of an irreversible inhibitor of polyamine biosynthesis, α-difluoromethylornithine (DFMO) and a non-steroidal anti-inflammatory drug (NSAID) Sulindac, which have been previously evaluated for colon cancer chemoprevention.

Digital image analysis using video microscopy of human-derived prostate cancer vs normal prostate organoids to assess migratory behavior on extracellular matrix proteins.

The advent of perpetuating living organoids derived from patient tissue is a promising avenue for cancer research but is limited by difficulties with precise characterization. In this brief communication, we demonstrate time-lapse imaging distinct phenotypes of prostate organoids derived from patient material- without confirmation of cellular identity. We show that organoids derived from histologically normal tissue more readily spread on a physiologic extracellular matrix (ECM) than on pathologic ECM (p<0.

Kallikrein-Related Peptidase 6 (KLK6) as a Contributor toward an Aggressive Cancer Cell Phenotype: A Potential Role in Colon Cancer Peritoneal Metastasis.

Kallikrein-related peptidases (KLKs) are implicated in many cancer-related processes. KLK6, one of the 15 KLK family members, is a promising biomarker for diagnosis of many cancers and has been associated with poor prognosis of colorectal cancer (CRC) patients. Herein, we evaluated the expression and cellular functions of KLK6 in colon cancer-derived cell lines and in clinical samples from CRC patients.

Molecular Pathways Associated with Kallikrein 6 Overexpression in Colorectal Cancer.

Colorectal cancer (CRC) remains one of the leading causes of cancer-related death worldwide. The high mortality of CRC is related to its ability to metastasize to distant organs. The kallikrein-related peptidase Kallikrein 6 (KLK6) is overexpressed in CRC and contributes to cancer cell invasion and metastasis.

Kallikrein 6 protease advances colon tumorigenesis induction of the high mobility group A2 protein.

Kallikrein-related peptidase 6 (KLK6) overexpression is commonly observed in primary tumors of colorectal cancer (CRC) patients and has been associated with tumor aggressiveness, metastasis, and poor prognosis. We previously established a unique contribution of KLK6 in colon cancer metastasis via a specific network of microRNAs and mRNAs. Here we evaluated the cellular functions of KLK6 protease in Caco-2 colon adenocarcinoma cell line after introduction of the enzymatically active or inactive form of the enzyme.

Synthesis and Structure-Activity Relationships of N-(4-Benzamidino)-Oxazolidinones: Potent and Selective Inhibitors of Kallikrein-Related Peptidase 6.

Kallikrein-related peptidase 6 (KLK6) is a secreted serine protease that belongs to the family of tissue kallikreins. Aberrant expression of KLK6 has been found in different cancers and neurodegenerative diseases, and KLK6 is currently studied as a potential target in these pathologies. We report a novel series of KLK6 inhibitors discovered in a high-throughput screen within the European Lead Factory program.

Does Mutated Oncogene Attenuate the Effect of Sulindac in Colon Cancer Chemoprevention?

The NSAID sulindac has been successfully used alone or in combination with other agents to suppress colon tumorigenesis in patients with genetic predisposition and also showed its efficacy in prevention of sporadic colon adenomas. At the same time, some experimental and clinical reports suggest that a mutant oncogene may negate sulindac antitumor efficacy. To directly assess sulindac activity at suppressing premalignant lesions carrying K-RAS mutation, we utilized a novel mouse model with an inducible colon-specific expression of the mutant oncogene ( ).

Detection of Enzyme Activity and Inhibition during Studies in Solution, In Vitro and In Vivo with CatalyCEST MRI.

Purpose: The detection of enzyme activities and evaluation of enzyme inhibitors have been challenging with magnetic resonance imaging (MRI). To address this need, we have developed a diamagnetic, nonmetallic contrast agent and a protocol known as catalyCEST MRI that uses chemical exchange saturation transfer (CEST) to detect enzyme activity as well as enzyme inhibition.

Procedures: We synthesized a diamagnetic MRI contrast agent that has enzyme responsive and enzyme unresponsive CEST signals.

Specific microRNA-mRNA Regulatory Network of Colon Cancer Invasion Mediated by Tissue Kallikrein-Related Peptidase 6.

Metastatic colon cancer is a major cause of deaths among colorectal cancer (CRC) patients. Elevated expression of kallikrein 6 (KLK6), a member of a kallikrein subfamily of peptidase S1 family serine proteases, has been reported in CRC and is associated with low patient survival rates and poor disease prognosis. We knocked down KLK6 expression in HCT116 colon cancer cells to determine the significance of KLK6 expression for metastatic dissemination and to identify the KLK6-associated microRNAs (miRNAs) signaling networks in metastatic colon cancer.

Mutant K-RAS Promotes Invasion and Metastasis in Pancreatic Cancer Through GTPase Signaling Pathways.

Pancreatic ductal adenocarcinoma is one of the most aggressive malignancies, characterized by the local invasion into surrounding tissues and early metastasis to distant organs. Oncogenic mutations of the K-RAS gene occur in more than 90% of human pancreatic cancers. The goal of this study was to investigate the functional significance and downstream effectors of mutant K-RAS oncogene in the pancreatic cancer invasion and metastasis.

Time-serial Assessment of Drug Combination Interventions in a Mouse Model of Colorectal Carcinogenesis Using Optical Coherence Tomography.

Optical coherence tomography (OCT) is a high-resolution, nondestructive imaging modality that enables time-serial assessment of adenoma development in the mouse model of colorectal cancer. In this study, OCT was utilized to evaluate the effectiveness of interventions with the experimental antitumor agent α-difluoromethylornithine (DFMO) and a nonsteroidal anti-inflammatory drug sulindac during early [chemoprevention (CP)] and late stages [chemotherapy (CT)] of colon tumorigenesis. Biological endpoints for drug interventions included OCT-generated tumor number and tumor burden.

Get the fat out!

Obesity is associated with increased risk of a number of cancers in humans, but the mechanism(s) responsible for these associations have not been established. It is estimated that 68% of adults are overweight or obese and that obesity may be causative in 4% to 7% of cancers in the United States. Several hypotheses have been put forward to explain the association between obesity and cancer including adipose-directed signaling (e.

Caveolin-1 is a novel regulator of K-RAS-dependent migration in colon carcinogenesis.

Caveolin-1 is an essential component of membrane caveolae. It is an important regulator of cellular processes such as signal transduction and endocytosis. We report here, for the first time, that caveolin-1 is a target of the K-RAS oncogene in colon carcinogenesis.

Polyamines in cancer.

Polyamines are organic cations shown to control gene expression at the transcriptional, posttranscriptional, and translational levels. Multiple cellular oncogenic pathways are involved in regulation of transcription and translation of polyamine-metabolizing enzymes. As a consequence of genetic alterations, expression levels and activities of polyamine-metabolizing enzymes change rapidly during tumorigenesis resulting in high levels of polyamines in many human epithelial tumors.

Defining the role of polyamines in colon carcinogenesis using mouse models.

Genetics and diet are both considered important risk determinants for colorectal cancer, a leading cause of death in the US and worldwide. Genetically engineered mouse (GEM) models have made a significant contribution to the characterization of colorectal cancer risk factors. Reliable, reproducible, and clinically relevant animal models help in the identification of the molecular events associated with disease progression and in the development of effictive treatment strategies.

Gene expression analysis of HCT116 colon tumor-derived cells treated with the polyamine analog PG-11047.

Background: The conformationally restricted polyamine analog PG-11047 has significant growth inhibitory activity against prostate and lung cancer cell lines and is currently under evaluation in several clinical trials, both alone and in combination with other drugs, for the treatment of relapsed or refractory cancer. The objective of this study was to identify the molecular signature of genes responsive to PG-11047 treatment and the biochemical effects of this drug in the HCT116 colon cancer cell line.

Materials And Methods: Gene expression analysis was performed using Affymetrix GeneChip human genome U133 Plus 2.

Combination chemoprevention of intestinal carcinogenesis in a murine model of familial adenomatous polyposis.

Familial adenomatous polyposis (FAP) is an autosomal dominantly inherited syndrome in humans. The Apc(Min/+) mouse, which expresses a mutant homolog of the adenomatous polyposis coli gene, is a model of FAP in humans. Treatment with the nonsteroidal anti-inflammatory drugs (NSAIDS) sulindac or celecoxib can suppress polyp development in FAP patients, but responses are generally transient and incomplete.

Kallikrein 6 is a mediator of K-RAS-dependent migration of colon carcinoma cells.

Kallikrein 6 (KLK6) is a trypsin-like serine peptidase whose relevance in various types of cancers is currently being explored. Previous studies have shown that KLK6 mRNA is upregulated in colon and gastric cancers; however, the regulatory mechanisms and phenotypic consequences of this upregulation are largely unknown. Activating K-RAS mutations are common in colon cancer, occurring in approximately 50% of cases.

Wild-type APC regulates caveolin-1 expression in human colon adenocarcinoma cell lines via FOXO1a and C-myc.

Genetic evidence suggests that caveolin-1, an essential component of membrane caveolae, acts as a tumor promoter in some, and a tumor suppressor in other cancers. The role of caveolin-1 in colon carcinogenesis is controversial. We report here, for the first time, that caveolin-1 is transcriptionally induced in colon cancer cells in response to conditional expression of a full length adenomatous polyposis coli (APC) gene.

Caveolin-1-mediated expression and secretion of kallikrein 6 in colon cancer cells.

Kallikreins are secreted proteases that may play a functional role and/or serve as a serum biomarker for the presence or progression of certain types of cancers. Kallikrein 6 (KLK6) has been shown to be upregulated in several types of cancers, including colon. The aims of this study were to elucidate pathways that influence KLK6 gene expression and KLK6 protein secretion in the HCT116 human colon cancer cells.

Serial endoscopy in azoxymethane treated mice using ultra-high resolution optical coherence tomography.

Purpose: Optical coherence tomography (OCT) is a minimally invasive, depth-resolved imaging tool that can be implemented in a small diameter endoscope for imaging mouse models of colorectal cancer (CRC). In this study, we utilized ultrahigh resolution (UHR) OCT to serially image the lower colon of azoxymethane (AOM) treated A/J mouse models of CRC in order to monitor the progression of neoplastic transformations and determine if OCT is capable of identifying early disease.

Experimental Design: Thirteen AOM treated A/J and two control A/J mice were surveyed at four timepoints (8, 14, 22 and 26 weeks post AOM treatment) using a 2.

Dietary putrescine reduces the intestinal anticarcinogenic activity of sulindac in a murine model of familial adenomatous polyposis.

The nonsteroidal antiinflammatory drug sulindac displays chemopreventive activity in patients with familial adenomatous polyposis (FAP). Sulindac metabolites induce apoptosis in colon tumor cells, in part, by a polyamine-dependent mechanism that can be suppressed with exogenous putrescine. To determine the relevance of this mechanism in animals, we treated Apc(Min/+) mice, a model of human FAP, with sulindac alone or in combination with dietary putrescine.

Deoxycholate-induced colitis is markedly attenuated in Nos2 knockout mice in association with modulation of gene expression profiles.

Nos2 knockout mice were compared to wild-type mice for susceptibility to colitis in response to a diet supplemented with deoxycholate, a bile acid increased in the colon of individuals on a high-fat diet. Wild-type mice fed a fat-related diet, supplemented with 0.2% DOC, develop colonic inflammation associated with increases in nitrosative stress, proliferation, oxidative DNA/RNA damage, and angiogenesis, as well as altered expression of numerous genes.