Major Histocompatibility Complex Genes as Therapeutic Opportunity for Immune Cold Molecular Cancer Subtypes.

Current immunotherapies are effective only in a subset of patients, likely due to several factors including defects in tumor cell antigen presentation, decreased response to immune effectors, and molecular heterogeneity of cancers. Recent molecular classifications enable the categorization of many tumor types. However, deregulation of major histocompatibility complex (MHC) gene expression is poorly characterized in the context of molecular cancer subtypes. To suppress the confounding effect of immune infiltrates on expression patterns of immunoregulators, we identified and removed genes with strong correlation to estimated immune compartment levels in each tumor type. Next, we reanalyzed a total of 13 TCGA cancer types encompassing 5651 tumors and 485 normal adjacent tissues by performing unsupervised clustering of 14 MHC genes. Subsequently, resultant clusters were statistically compared in terms of expression of other immune-related genes. Three MHC expression clusters were discovered by unsupervised clustering. We identified concordantly decreased expression of MHC genes (MHC-low) in 26 out of 55 molecular subtypes. Consequently, our study underlines the urgent need for designing strategies to enhance tumor MHC expression that could improve immune cold tumor rejection by cytotoxic T lymphocytes.

Transcriptomic Profiling for the Autophagy Pathway in Colorectal Cancer.

The role of autophagy in colorectal cancer (CRC) pathogenesis appears to be crucial. Autophagy acts both as a tumor suppressor, by removing redundant cellular material, and a tumor-promoting factor, by providing access to components necessary for growth, metabolism, and proliferation. To date, little is known about the expression of genes that play a basal role in the autophagy in CRC. In this study, we aimed to compare the expression levels of 46 genes involved in the autophagy pathway between tumor-adjacent and tumor tissue, employing large RNA sequencing (RNA-seq) and microarray datasets. Additionally, we verified our results using data on 38 CRC cell lines. Gene set enrichment analysis revealed a significant deregulation of autophagy-related gene sets in CRC. The unsupervised clustering of tumors using the mRNA levels of autophagy-related genes revealed the existence of two major clusters: microsatellite instability (MSI)-enriched and -depleted. In cluster 1 (MSI-depleted), ATG9B and LAMP1 genes were the most prominently expressed, whereas cluster 2 (MSI-enriched) was characterized by DRAM1 upregulation. CRC cell lines were also clustered according to MSI-enriched/-depleted subgroups. The moderate deregulation of autophagy-related genes in cancer tissue, as compared to adjacent tissue, suggests a prominent field cancerization or early disruption of autophagy. Genes differentiating these clusters are promising candidates for CRC targeting therapy worthy of further investigation.

Expression Analysis of Tyrosine Phosphatase Genes at Different Stages of Renal Cell Carcinoma.

BACKGROUND: Renal cell carcinoma (RCC) is a common urological cancer, and its risk correlates with environmental factors such as obesity, smoking and hypertension. Microarray technology enables analysis of the expression pattern of the whole phosphatome, members of which are involved in many cellular pathways and may act as either tumour suppressors or oncogenes in cancers. MATERIALS AND METHODS: We analysed data for the expression level of 87 out of 107 known protein phosphatase genes included in the Hugo Gene Nomenclature Committee Website for 72 RCC tissues and paired healthy tissues obtained from the GEO Database. RESULTS: Our analysis revealed overexpression of DUSP1, DUSP4, PTP4A3, PTPRC and PTPRE genes at all examined stages of RCC. Moreover, we found overexpression of PTPN12 at stage 2, overexpression of CDKN3 at stages 3 and 4, and overexpression of DUSP10 and PTPN22 at stages 2, 3 and 4. Lower expression of DUSP9, PTPR9 and PTPRO was also observed at all stages. CONCLUSION: Significant changes in expression patterns of protein tyrosine phosphatase genes confirm the involvement of this group in crucial carcinogenesis pathways underlying RCC. Thus, we postulate that protein tyrosine phosphatases play an important role in RCC promotion and progression, and may be considered as potential therapeutic targets.

Genetic testing in Poland and Ukraine: should comprehensive germline testing of BRCA1 and BRCA2 be recommended for women with breast and ovarian cancer?

PURPOSE: To characterize the spectrum of BRCA1 and BRCA2 pathogenic germline variants in women from south-west Poland and west Ukraine affected with breast or ovarian cancer. Testing in women at high risk of breast and ovarian cancer in these regions is currently mainly limited to founder mutations. METHODS: Unrelated women affected with breast and/or ovarian cancer from Poland (n = 337) and Ukraine (n = 123) were screened by targeted sequencing. Excluded from targeted sequencing were 34 Polish women who had previously been identified as carrying a founder mutation in BRCA1. No prior testing had been conducted among the Ukrainian women. Thus, this study screened BRCA1 and BRCA2 in the germline DNA of 426 women in total. RESULTS: We identified 31 and 18 women as carriers of pathogenic/likely pathogenic (P/LP) genetic variants in BRCA1 and BRCA2, respectively. We observed five BRCA1 and eight BRCA2 P/LP variants (13/337, 3.9%) in the Polish women. Combined with the 34/337 (10.1%) founder variants identified prior to this study, the overall P/LP variant frequency in the Polish women was thus 14% (47/337). Among the Ukrainian women, 16/123 (13%) women were identified as carrying a founder mutation and 20/123 (16.3%) were found to carry non-founder P/LP variants (10 in BRCA1 and 10 in BRCA2). CONCLUSIONS: These results indicate that genetic testing in women at high risk of breast and ovarian cancer in Poland and Ukraine should not be limited to founder mutations. Extended testing will enhance risk stratification and management for these women and their families.

The First Evidence of Cryptosporidium meleagridis Infection in a Colon Adenocarcinoma From an Immunocompetent Patient.

Objectives: The potential linkage between Cryptosporidium spp. infection and colorectal human cancer was suggested by limited reports showing higher prevalence of C. parvum and C. hominis in patients with colon cancer. Here we conducted research concerning presence of Cryptosporidium spp. in malignant tissue collected from patients with colorectal cancer. Methods: Cancerous colon tissue samples collected from 145 non-HIV infected patients with colorectal cancer were screened for Cryptosporidium spp. by immunofluorescence antibody test and genus-specific nested polymerase chain reaction followed by sequencing. Results: Screened pathogen was found in cancerous tissue originating from immunocompetent man with colon adenocarcinoma. Genotyping revealed presence of Cryptosporidium meleagridis. The presence of Cryptosporidium life cycle stages (oocysts and endogenous stages) in colon carcinoma tissue was confirmed by genus-specific FITC-labeling. Conclusions: Herein, we report on a C. meleagridis infection of a colon adenocarcinoma in an immunocompetent patient. This is the first report of C. meleagridis infection in the human colon and first evidence of active development of this species in cancer tissue.

Meta-analysis of association between Arg326Gln (rs1503185) and Gln276Pro (rs1566734) polymorphisms of PTPRJ gene and cancer risk.

Protein tyrosine phosphatase receptor type J (PTPRJ, DEP1) is a tumour suppressor gene that negatively regulates such processes as angiogenesis, cell proliferation and migration and is one of the genes important for tumour development. Similar to other phosphatase genes, PTPRJ is also described as an oncogene. Among various genetic changes characteristic for this gene, single nucleotide polymorphisms (SNPs) constituting benign genetic variants that can modulate its function have been described. We focused on Gln276Pro and Arg326Gln missense polymorphisms and performed a meta-analysis using data from 2930 and 852 patients for Gln276Pro and Arg326Gln respectively in different cancers. A meta-analysis was performed based on five articles accessed via the PubMed and Research Gate databases. Our meta-analysis revealed that for Arg326Gln, the presence of the Arg (C) allele was associated with lower risk of some cancers, the strongest association was observed for colorectal cancer patients, and there was no association between Gln276Pro (G>T) polymorphism and cancer risk. The polymorphisms Arg326Gln and Gln276Pro of the PTPRJ gene are not associated with an increased risk of cancer except for the Arg326Gln polymorphism in colorectal cancer. Large-scale studies should be performed to verify the impact of this SNP on individual susceptibility to colorectal cancer for given individuals.

The Influence of Tumor Microenvironment on ATG4D Gene Expression in Colorectal Cancer Patients.

Despite great progress in research on the subject, the involvement of autophagy in colorectal cancer (CRC) pathogenesis (initiation, progression, metastasis) remains obscure and controversial. Autophagy is a catabolic process, fundamental to cell viability and connected with degradation/recycling of proteins and organelles. In this study, we aimed at investigating the relative expression level of mRNA via Real-Time PCR of 16 chosen genes belonging to Atg8 mammalian orthologs and their conjugation system, comprising GABARAP, GABARAPL1, GABARAPL2, MAP1LC3A, MAP1LC3B, MAP1LC3C, ATG3, ATG7, ATG10, ATG4A, ATG4B, ATG4C, ATG4D, and three genes encoding proteins building the multimeric ATG16L1 complex, namely ATG5, ATG12, and ATG16L1, in 73 colorectal tumors and paired adjacent normal colon mucosa. Our study demonstrated the relative downregulation of all examined genes in CRC tissues in comparison to adjacent noncancerous mucosa, with the highest rate of expression in both tumor and non-tumor tissues observed for GAPARBPL2 and the lowest for MAP1LC3C. Moreover, in patients with advanced-stage tumors and high values of regional lymph nodes, statistically significant downregulation of ATG4D expression in adjacent normal cells was observed. Our study confirms the role of autophagy genes as cancer suppressors in colorectal carcinogenesis. Furthermore, in regard to the ATG4D gene, we observed the influence of tumor microenvironments on gene expression in adjacent colon mucosa.

Personalized medicine in oncology. New perspectives in management of gliomas.

Studies on genetic and epigenetic mechanisms of carcinogenesis have led to the discovery of crucial genetic events for many of particular malignancies. This was followed by invention of new therapeutic approaches based on molecular mechanisms underlying cancer development and progression that bears the name of personalised medicine. In the case of gliomas, ascertainment of genetic/epigenetic markers was the basis for re-classification of tumours that until now depended on histopathological analysis. This article reviews recent advances in personalised medicine and the new World Health Organisation classification of gliomas.

FANCM and RECQL genetic variants and breast cancer susceptibility: relevance to South Poland and West Ukraine.

BACKGROUND: FANCM and RECQL have recently been reported as breast cancer susceptibility genes and it has been suggested that they should be included on gene panel tests for breast cancer predisposition. However, the clinical value of testing for mutations in RECQL and FANCM remains to be determined. In this study, we have characterised the spectrum of FANCM and RECQL mutations in women affected with breast or ovarian cancer from South-West Poland and West Ukraine. METHODS: We applied Hi-Plex, an amplicon-based enrichment method for targeted massively parallel sequencing, to screen the coding exons and proximal intron-exon junctions of FANCM and RECQL in germline DNA from unrelated women affected with breast cancer (n = 338) and ovarian cancer (n = 89) from Poland (n = 304) and Ukraine (n = 123). These women were at high-risk of carrying a genetic predisposition to breast and/or ovarian cancer due to a family history and/or early-onset disease. RESULTS: Among 427 women screened, we identified one carrier of the FANCM:c.1972C > T nonsense mutation (0.23%), and two carriers of the frameshift insertion FANCM:c.1491dup (0.47%). None of the variants we observed in RECQL were predicted to be loss-of-function mutations by standard variant effect prediction tools. CONCLUSIONS: Our study of the Polish and Ukrainian populations has identified a carrier frequency of truncating mutations in FANCM consistent with previous reports. Although initial reports suggesting that mutations in RECQL could be associated with increased breast cancer risk included women from Poland and identified the RECQL:c.1667_1667 + 3delAGTA mutation in 0.23-0.35% of breast cancer cases, we did not observe any carriers in our study cohort. Continued screening, both in research and diagnostic settings, will enable the accumulation of data that is needed to establish the clinical utility of including RECQL and FANCM on gene panel tests.

Targeted massively parallel sequencing characterises the mutation spectrum of PALB2 in breast and ovarian cancer cases from Poland and Ukraine.

Loss-of-function germline mutations in the PALB2 gene are associated with an increase of breast cancer risk. The purpose of this study was to characterise the spectrum of PALB2 mutations in women affected with breast or ovarian cancer from South-West Poland and West Ukraine. We applied Hi-Plex, an amplicon-based enrichment method for targeted massively parallel sequencing, to screen the coding exons and proximal intron-exon junctions of PALB2 in germline DNA from unrelated women affected with breast cancer (n = 338) and ovarian cancer (n = 89) from Poland (n = 304) and Ukraine (n = 123). These women were at high-risk of carrying a genetic predisposition to breast and/or ovarian cancer due to a family history and/or early-onset disease. Targeted-sequencing identified two frameshift deletions: PALB2:c.509_510del; p.R170Ifs in three women affected with breast cancer and PALB2:c.172_175del;p.Q60Rfs in one woman affected with ovarian cancer. A number of other previously described missense (some predicted to be damaging by PolyPhen-2 and CADD) and synonymous mutations were also identified in this population. This study is consistent with previous reports that PALB2:c.509_510del and PALB2:c.172_175del are recurrent mutations associated with breast cancer predisposition in Polish women with a family history of the disease. Our study contributes to the accumulating evidence indicating that PALB2 should be included in genetic testing for breast cancer susceptibility in these populations to enhance risk assessment and management of women at high-risk of developing breast cancer. This data could also contribute to ongoing work that is assessing the possible association between ovarian cancer risk and PALB2 mutations for which there is currently no evidence.

Pan-cancer analysis reveals presence of pronounced DNA methylation drift in CpG island methylator phenotype clusters.

AIM: To provide characteristics of major genomic correlates in CpG island methylator phenotype-high (CIMP-H) subgroups in relation to corresponding non-CIMP-H subgroups by use of phenotypic, DNA methylation and RNAseq data. MATERIALS & METHODS: Twenty-three datasets generated by The Cancer Genome Atlas project encompassing over 7200 unique samples were analyzed. We identified 23 CIMP-H clusters by use of unsupervised clustering. RESULTS & CONCLUSION: More than 90% of CIMP-H clusters were significantly associated with accelerated epigenetic mitotic clock, demethylation of enhancer sites, backbone and repetitive sequences. Pronounced epigenetic drift observed in majority of CIMP-H subgroups may be related to increased cell division rate, which leads to expansion of DNA methylation errors. This may explain pan-cancer mechanism of establishing CIMP-H in majority of tissue types.

Genetic Factors Involved in Mandibular Prognathism.

Mandibular prognathism is defined as an abnormal forward projection of the mandible beyond the standard relation to the cranial base and it is usually categorized as both a skeletal Class III pattern and Angle Class III malocclusion. The etiology of mandibular prognathism is still uncertain, with various genetic, epigenetic, and environmental factors possibly involved. However, many reports on its coexistence in both twins and segregation in families suggest the importance of genetic influences. A multifactorial and polygenic background with a threshold for expression or an autosomal dominant mode with incomplete penetrance and variable expressivity are the most probable inheritance patterns. Linkage analyses have, thus far, shown the statistical significance of such loci as 1p22.1, 1p22.3, 1p32.2, 1p36, 3q26.2, 4p16.1, 6q25, 11q22, 12pter-p12.3, 12q13.13, 12q23, 12q24.11, 14q24.3 to 31.2, and 19p13.2. The following appear among candidate genes: MATN1, EPB41, growth hormone receptor, COL2A1, COL1A1, MYO1H, DUSP6, ARHGAP21, ADAMTS1, FGF23, FGFR2, TBX5, ALPL, HSPG2, EVC, EVC2, the HoxC gene cluster, insulin-like growth factor 1, PLXNA2, SSX2IP, TGFB3, LTBP2, MMP13/CLG3, KRT7, and FBN3. On the other hand, MYH1, MYH2, MYH3, MYH7, MYH8, FOXO3, NFATC1, PTGS2, KAT6B, HDAC4, and RUNX2 expression is suspected to be involved in the epigenetic regulations behind the mandibular prognathism phenotype.

Customized Array Comparative Genomic Hybridization Analysis of 25 Phosphatase-encoding Genes in Colorectal Cancer Tissues.

BACKGROUND/AIM: Molecular mechanisms of alterations in protein tyrosine phosphatases (PTPs) genes in cancer have been previously described and include chromosomal aberrations, gene mutations, and epigenetic silencing. However, little is known about small intragenic gains and losses that may lead to either changes in expression or enzyme activity and even loss of protein function. MATERIALS AND METHODS: The aim of this study was to investigate 25 phosphatase genes using customized array comparative genomic hybridization in 16 sporadic colorectal cancer tissues. RESULTS: The analysis revealed two unique small alterations: of 2 kb in PTPN14 intron 1 and of 1 kb in PTPRJ intron 1. We also found gains and losses of whole PTPs gene sequences covered by large chromosome aberrations. CONCLUSION: In our preliminary studies using high-resolution custom microarray we confirmed that PTPs are frequently subjected to whole-gene rearrangements in colorectal cancer, and we revealed that non-polymorphic intragenic changes are rare.

The BAX gene as a candidate for negative autophagy-related genes regulator on mRNA levels in colorectal cancer.

Autophagy is a catabolic process, which is involved in the maintenance of intracellular homeostasis by degrading redundant molecules and organelles. Autophagy begins with the formation of a double-membrane phagophore, followed by its enclosure, thus leading to the appearance of an autophagosome which fuses with lysosome. This process is highly conserved, precisely orchestrated and regulated by autophagy-related genes. Recently, autophagy has been widely studied in different types of cancers, including colorectal cancer. As it has been revealed, autophagy plays two opposite roles in tumorigenesis, as a tumor suppressor and a tumor enhancer/activator, and therefore is called a double-edge sword. Recently, interaction between autophagy and apoptosis has been found. Therefore, we aimed to study the mRNA levels of genes engaged in autophagy and apoptosis in colorectal cancer tissues. Colorectal cancer and adjacent healthy tissues were obtained from 73 patients diagnosed with primary colorectal cancer. Real-time PCR analysis employing Universal Probe Library was used to assess the expression of the seven following selected genes: BECN1, UVRAG, ULK1, ATG13, Bif-1, BCL2 and BAX. For all but one of the tested genes, a decrease in expression was observed. An increase in expression was observed for BAX. BAX expression decreases consistently from early to more advanced stages. High expression of BAX was strongly associated with negative UVRAG expression. The high expression of the BAX gene seems to be a negative regulator of autophagy in colorectal cancer cells. The relative downregulation of autophagy-related genes was observed in colorectal cancer samples.

May autophagy be a novel biomarker and antitumor target in colorectal cancer?

Autophagy is a catabolic process associated with intracellular self-digestion of damaged organelles or redundant proteins enabling maintenance of cell homeostasis. It is accepted that impaired autophagy is closely linked to cancer development and has been extensively studied in a variety of malignancies including colorectal cancer (CRC) to elucidate its influence on carcinogenesis, metastasis and antitumor therapy response. CRC remains a great epidemiological problem because of poor 5-year survival and treatment resistance. Many studies concerning autophagy in CRC gave inconsistent and contradictory results, illustrating a multifaceted nature of this process. In this review, we focus on current knowledge of autophagy in CRC development to determinate its role as a potential prognostic and predictive biomarker as well as target in antitumor therapy.

Novel COL4A1 mutation in an infant with severe dysmorphic syndrome with schizencephaly, periventricular calcifications, and cataract resembling congenital infection.

BACKGROUND: A clinical case is described of growth retardation, severe developmental delay, facial dysmorphic features with microcephaly, as well as congenital cataract, schizencephaly, periventricular calcifications, and epilepsy. METHODS: TORCH infection was suspected, but all tests for toxoplasmosis, rubella, cytomegalovirus, and herpes simplex virus were negative for the child and her mother; however, an increased level of antibodies against parvovirus B19 was detected in the proband. RESULTS: Chromosomal analysis and array-CGH showed no aberration. Target capture sequencing for COL4A1 and COL4A2 revealed a de novo COL4A1 mutation (c.2123G>T [p.Gly708Val]). The mutation occurred at a highly conserved Gly residue in the Gly-X-Y repeat of the collagen triple helical domain, suggesting that these mutations may alter the collagen IV α1α1α2 heterotrimers. The mutation was predicted to be damaging. CONCLUSION: We suggest that COL4A1 testing should be considered in patients with schizencephaly as well as with phenotype suggesting TORCH infection without any proven etiological factors.

High PTPRQ Expression and Its Relationship to Expression of PTPRZ1 and the Presence of KRAS Mutations in Colorectal Cancer Tissues.

BACKGROUND: The risk of sporadic colorectal cancer (CRC) is strongly influenced by Iifestyle, environmental and genetic factors. Protein tyrosine phosphatases belong to a group of enzymes whose role in CRC has not yet been intensively studied. They play an important role in activation/de-activation of many enzymes, influencing cell biology by catalyzing reactions opposing those catalyzed by kinases. Protein tyrosine phosphatase receptor-like type Q (PTPRQ) and protein tyrosine phosphatase receptor-like type Z polypeptide 1 (PTPRZ1) have both been shown to be important in development of many cancer types including CRC. MATERIALS AND METHODS: The expression level of PTPRQ and PTPRZ1 was determined by real-time polymerase chain reaction in 16 CRC tissues obtained from patients diagnosed with adenocarcinoma coli. RESULTS: We revealed a high level of PTPRQ expression (p=0.0080), as well as an association between expression levels of PTPRQ and PTPRZ1 (p<0.0001). Moreover PTPRQ expression was higher in tissues presenting with Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation (p=0.0293). CONCLUSION: We confirmed the contribution of PTPRZ1 and especially PTPRQ in CRC development, supporting the hypothesis that PTPRQ is a candidate oncogene, playing a crucial role in phosphorylation/dephosphorylation signaling pathways.

Lower LINE-1 methylation in first-episode schizophrenia patients with the history of childhood trauma.

AIM: We investigated methylation of DNA repetitive sequences (LINE-1 and BAGE) in peripheral blood leukocytes from first-episode schizophrenia (FES) patients and healthy controls (HCs) with respect to childhood adversities. MATERIALS & METHODS: Patients were divided into two subgroups based on the history of childhood trauma - FES(+) and FES(-) subjects. The majority of HCs had a negative history of childhood trauma - HCs(-) subjects. RESULTS: FES(+) patients had significantly lower LINE-1 methylation in comparison with FES(-) patients or HC(-) subjects. Emotional abuse and total trauma score predicted lower LINE-1 methylation in FES patients, while general trauma score was associated with lower BAGE methylation in HCs. CONCLUSION: Childhood adversities might be associated with global DNA hypomethylation in adult FES patients.

Aberrant methylation of ERBB pathway genes in sporadic colorectal cancer.

The ErbB signalling network plays a crucial role in the growth and progression of several cancers, including colorectal cancer (CRC), and includes potentially drug-targetable genes. Oncogenic activation of the ErbB pathway by mutations and focal amplifications have emerged recently as an important predictive marker of the prognosis of CRC patients. However, in contrast to genetic events, little is known about epigenetic alternations of ErbB-associated genes and their impact on gene expression. Genome-wide methylation in sporadic CRCs (n = 12) paired with adjacent normal tissues have been previously analysed by Illumina Infinium HumanMethylation27 (HM27) at 27,578 CpG sites. For confirmation of our initial genome-wide analysis, we used a published HM27 dataset (GSE25062). Subsequently, CpG island methylation of selected ErbB pathway-associated genes was assessed on 233 CRC samples using methylation-sensitive polymerase chain reaction (MS-PCR) and analysed along with various genetic factors associated with CRC [epigenotype, BRAF and KRAS mutations, microsatellite instability (MSI)]. Methylation and expression integration was performed using published datasets including 25 pairs of CRC and normal colon tissues (GSE25062 and GSE25070), and confirmed with real-time PCR. Our previous microarray-based genome-wide DNA methylation analysis of 12 CRCs revealed that four ErbB-associated genes (PIK3CD, PKCΒ, ERBB4, ) were differentially methylated in CRCs. This was further confirmed by statistical re-analysis of an HM27 dataset (GSE25062). Frequent methylation at these loci in tumours was subsequently confirmed by MS-PCR (63%, 43%, 43% and 92%, respectively). Hypermethylation of PKCΒ associated with KRAS mutation (p = 0.04), whereas hypermethylation of ERBB4 associated with high-methylation epigenotypes (HME), BRAF mutation and MSI (p = 0.001, 0.002 and 0.0002, respectively). One of the four analysed genes (PKCΒ) was significantly downregulated in CRC tissue, as revealed by real-time PCR and re-analysis of the GSE25062 and GSE25070 datasets. After careful re-analysis of published methylation and expression data, we conclude that methylation of ERBB4, PAK7 and PIK3CD has no functional role in CRC carcinogenesis. In contrast, methylation seems to have a potential impact on the biology of colorectal tumours by negatively modulating the expression of PKCΒ. Importantly, the relationship between DNA methylation of PKCΒ and gene expression may warrant further attention in the context of colon cancer chemoprevention and anti-cancer therapy.