Different Roles of Apoptosis and Autophagy in the Development of Human Colorectal Cancer.

Colorectal cancer (CRC) remains a major life-threatening malignancy, despite numerous therapeutic and screening attempts. Apoptosis and autophagy are two processes that share common signaling pathways, are linked by functional relationships and have similar protein components. During the development of cancer, the two processes can trigger simultaneously in the same cell, causing, in some cases, an inhibition of autophagy by apoptosis or apoptosis by autophagy. Malignant cells that have accumulated genetic alterations can take advantage of any alterations in the apoptotic process and as a result, progress easily in the cancerous transformation. Autophagy often plays a suppressive role during the initial stages of carcinogenicity, while in the later stages of cancer development it can play a promoting role. It is extremely important to determine the regulation of this duality of autophagy in the development of CRC and to identify the molecules involved, as well as the signals and the mechanisms behind it. All the reported experimental results indicate that, while the antagonistic effects of autophagy and apoptosis occur in an adverse environment characterized by deprivation of oxygen and nutrients, leading to the formation and development of CRC, the effects of promotion and collaboration usually involve an auxiliary role of autophagy compared to apoptosis. In this review, we elucidate the different roles of autophagy and apoptosis in human CRC development.

Biallelic PMS2 Mutations in a Family with Uncommon Clinical and Molecular Features.

We describe a patient with constitutional mismatch repair-deficiency (CMMR-D) in whom the syndrome started at age 10 with the development of multiple adenomas in the large bowel. In the successive 25 years, four malignancies developed in different organs (rectum, ileum, duodenum, and lymphoid tissue). The patient had biallelic constitutional pathogenic variants in the PMS2 gene. We speculate that besides the PMS2 genotype, alterations of other genes might have contributed to the development of the complex phenotype. In the nuclear family, both parents carried different PMS2 germline mutations. They appeared in good clinical condition and did not develop polyps or cancer. The index case had a brother who died at age three of lymphoblastic leukemia, and a sister who was affected by sarcoidosis. Tumor tissue showed diffuse DNA microsatellite instability. A complete absence of immunoreactivity was observed for the PMS2 protein both in the tumors and normal tissues. Next-generation sequencing and multiple ligation-dependent probe amplification analyses revealed biallelic PMS2 germline pathogenic variants in the proband (genotype c.[137G>T];[(2174+1_2175-1)_(*160_?)del]), and one of the two variants was present in both parents-c.137G>T in the father and c.(2174+1-2175-1)_(*160_?)del in the mother-as well as c.137G>T in the sister. Moreover, Class 3 variants of MSH2 (c.1787A>G), APC (c.1589T>C), and CHEK2 (c.331G>T) genes were also detected in the proband. In conclusion, the recognition of CMMR-D may sometimes be difficult; however, the possible role of constitutional alterations of other genes in the development of the full-blown phenotype should be investigated in more detail.

Gender differences in Anxious-depressive symptomatology, Metabolic Syndrome and Colorectal Adenomas among outpatients undergoing colonoscopy: a cross-sectional study according to a PNEI perspective.

BACKGROUND AND AIM OF THE WORK: To explore gender differences in patients suffering from anxious-depressive symptoms, Metabolic Syndrome (MetS) and Colorectal Adenomas (CRAs) in a sample of outpatients undergoing colonoscopy for screening purposes. METHODS: Cross-sectional study. 126 consecutive outpatients of both sexes undergoing colonoscopy for non-specific abdominal symptoms between January 2015 and June 2021 at the Modena Policlinico General Hospital (Modena, Northern Italy) were enrolled. MetS was diagnosed according to ATPIII and IDF criteria. Anxiety and depression were assessed with the Hospital Anxiety and Depression Scale (HADS), while the Temperament and Character Inventory (TCI) was used to study personality. The SF-36 was also included as a measure of quality of life perception. RESULTS: Among 126 outpatients (51.60% male) undergoing colonoscopy, 51 (44%) had CRAs, 54 (47%) MetS, 41 (41.40%) anxiety symptoms, 22 (22.20%) depressive symptoms and 13 (13.10%) combined anxious-depressive symptoms. HADS-Anxiety (t=2.68, p=0.01) and TCI Reward Dependence (TCI-RD) (t=3.01, p=0.00) mean scores were significantly higher in women; conversely, SF-36 Mental Component Summary scores were higher in men. CRAs were significantly prevalent in men (χ2=9.32, p=0.00) and were statistically significantly associated with male sex at the univariate logistic regression analysis (OR=3.27; p<0.01). At the multivariate logistic regression, diastolic hypertension (p<0.01) was positively associated with male sex, while TCI-RD (p=0.04) and HDL hypocholesterolemia (p=0.02) were inversely associated with male sex. CONCLUSIONS: Several significant gender differences in anxious-depressive symptoms, MetS and CRAs were found. These preliminary data suggest the need to consider gender specificities while implementing therapeutic, diagnostic, and preventive strategies.

Expression of Autophagic and Inflammatory Markers in Normal Mucosa of Individuals with Colorectal Adenomas: A Cross Sectional Study among Italian Outpatients Undergoing Colonoscopy.

Colorectal cancer (CRC) ranks among the three most common cancers in terms of both cancer incidence and cancer-related deaths in Western industrialized countries. Lifetime risk of colorectal cancer may reach 6% of the population living in developed countries. In the current era of personalized medicine, CRC is no longer considered as a single entity. In more recent years many studies have described the distinct differences in epidemiology, pathogenesis, genetic and epigenetic alterations, molecular pathways and outcome depending on the anatomical site. The aim of our study is to assess in a multidimensional model the association between metabolic status and inflammatory and autophagic changes in the normal colorectal mucosa classified as right-sided, left-sided and rectum, and the presence of adenomas. One hundred and sixteen patients undergoing colonoscopy were recruited and underwent a complete serum lipid profile, immunofluorescence analysis of colonic biopsies for MAPLC3 and myeloperoxidase expression, matched with clinical and anthropometric characteristics. Presence of adenomas correlated with cholesterol (total and LDL) levels, IL-6 levels, and MAPLC3 tissue expression, especially in the right colon. In conclusion, serum IL-6 amount and autophagic markers could be good predictors of the presence of colorectal adenomas.

The Combination of AHCC and ETAS Decreases Migration of Colorectal Cancer Cells, and Reduces the Expression of LGR5 and Notch1 Genes in Cancer Stem Cells: A Novel Potential Approach for Integrative Medicine.

The AHCC standardized extract of cultured Lentinula edodes mycelia, and the standardized extract of Asparagus officinalis stem, trademarked as ETAS, are well known supplements with immunomodulatory and anticancer potential. Several reports have described their therapeutic effects, including antioxidant and anticancer activity and improvement of immune response. In this study we aimed at investigating the effects of a combination of AHCC and ETAS on colorectal cancer cells and biopsies from healthy donors to assess the possible use in patients with colorectal cancer. Our results showed that the combination of AHCC and ETAS was synergistic in inducing a significant decrease in cancer cell growth, compared with single agents. Moreover, the combined treatment induced a significant increase in apoptosis, sparing colonocytes from healthy donors, and was able to induce a strong reduction in migration potential, accompanied by a significant modulation of proteins involved in invasiveness. Finally, combined treatment was able to significantly downregulate LGR5 and Notch1 in SW620 cancer stem cell (CSC) colonospheres. Overall, these findings support the potential therapeutic benefits of the AHCC and ETAS combinatorial treatment for patients with colorectal cancer.

Autoimmunity Profiles as Prognostic Indicators in Patients with Colorectal Cancer versus Those with Cancer at Other Sites: A Prospective Study.

Colorectal cancer represents a paradigmatic model of inflammatory carcinogenesis accompanied by the production of several kinds of tumor-associated autoantibodies (TAABs). The specific aim of this study is to define the clinical impact of the presence of non-specific circulating TAABs in a cohort of cancer patients and to establish whether significant differences were present between colorectal cancer and cancers at other sites. For this aim a prospective study was developed and a five-year survival analysis performed. Indirect immunofluorescence on rat tissues for non-organ specific autoantibodies (NOSAs: liver-kidney-stomach), on rat colon substrates (colon-related autoantibodies, CAAs) and on HEp-2 cell lines was performed. NOSA positivity was more frequent in patients with colorectal cancer than in those with cancer at other sites. Survival analysis demonstrated a significantly worse prognosis in cancer patients positive for TAABs. CAA positivity is a predictor of survival, independently from the presence of comorbidities, and HEp-2 reactivity was a strong predictor of survival in a stepwise Cox-regression model, including stage at diagnosis. Overall overproduction of TAABs is associated with advanced oncological disease, the presence of metastasis, and poorer prognosis of cancer patients.

Automated capture-based NGS workflow: one thousand patients experience in a clinical routine framework.

OBJECTIVES: The Next Generation Sequencing (NGS) based mutational study of hereditary cancer genes is crucial to design tailored prevention strategies in subjects with different hereditary cancer risk. The ease of amplicon-based NGS library construction protocols contrasts with the greater uniformity of enrichment provided by capture-based protocols and so with greater chances for detecting larger genomic rearrangements and copy-number variations. Capture-based protocols, however, are characterized by a higher level of complexity of sample handling, extremely susceptible to human bias. Robotics platforms may definitely help dealing with these limits, reducing hands-on time, limiting random errors and guaranteeing process standardization. METHODS: We implemented the automation of the CE-IVD SOPHiA Hereditary Cancer Solution™ (HCS) libraries preparation workflow by SOPHiA GENETICS on the Hamilton's STARlet platform. We present the comparison of results between this automated approach, used for more than 1,000 DNA patients' samples, and the performances of the manual protocol evaluated by SOPHiA GENETICS onto 240 samples summarized in their HCS evaluation study. RESULTS: We demonstrate that this automated workflow achieved the same expected goals of manual setup in terms of coverages and reads uniformity, with extremely lower standard deviations among samples considering the sequencing reads mapped onto the regions of interest. CONCLUSIONS: This automated solution offers same reliable and affordable NGS data, but with the essential advantages of a flexible, automated and integrated framework, minimizing possible human errors and depicting a laboratory's walk-away scenario.

Preliminary results of a multidisciplinary Italian study adopting a Psycho-Neuro-Endocrine-Immunological (PNEI) approach to the study of colorectal adenomas.

Background and aim of the work Colorectal mucosal precancerous lesions, metabolic syndrome (MetS) and psychiatric disorders may share a common low-grade local and systemic inflammation. Aim is to report on preliminary data concerning a research adopting a psycho-neuro-endocrine-immune (PNEI) approach to study outpatients undergoing colonoscopy. Methods A sample of patients undergoing colonoscopy was cross-sectionally investigated. Data on colorectal adenomas, MetS, early atherosclerosis, anxious-depressive symptoms, personality traits, and inflammatory markers were statistically analyzed. Results Sixty-two patients were recruited (female 50%, mean age: 60.8±9.4 years). The prevalence of adenomas and MetS was respectively of 45.2% and 41.9%. Anxiety and depressive symptoms were detected in 16 (32.7%) and 9 (18.4%) subjects, respectively. The presence of adenomas positively correlated with male sex (p=0.01), age (p<0.01), IL-6 (p=0.03), hsCRP (p=0.04), and MetS (p=0.03); it was also associated with hsCRP concentration (aOR=3.81, p=0.03). Conclusions Proinflammatory atherogenic status, psychological traits, increased mucosal inflammation, and metabolic parameters may share a common a pathogenic mechanism, worth studying.

Deep learning techniques for detecting preneoplastic and neoplastic lesions in human colorectal histological images.

Trained pathologists base colorectal cancer identification on the visual interpretation of microscope images. However, image labeling is not always straightforward and this repetitive task is prone to mistakes due to human distraction. Significant efforts are underway to develop informative tools to assist pathologists and decrease the burden and frequency of errors. The present study proposes a deep learning approach to recognize four different stages of cancerous tissue development, including normal mucosa, early preneoplastic lesion, adenoma and cancer. A dataset of human colon tissue images collected and labeled over a 10-year period by a team of pathologists was partitioned into three sets. These were used to train, validate and test the neural network, comprising several convolutional and a few linear layers. The approach used in the present study is 'direct'; it labels raw images and bypasses the segmentation step. An overall accuracy of >95% was achieved, with the majority of mislabeling referring to a near category. Tests on an external dataset with a different resolution yielded accuracies >80%. The present study demonstrated that the neural network, when properly trained, can provide fast, accurate and reproducible labeling for colon cancer images, with the potential to significantly improve the quality and speed of medical diagnoses.

The Association Between Symptoms of Anxiety, Depression, and Cardiovascular Risk Factors: Results From an Italian Cross-Sectional Study.

Cardiovascular diseases, anxiety, and depression are among the most frequent clinical conditions in the Western world, often in comorbidity. Evidence regarding a shared pathophysiology suggests a mediating role by chronic systemic inflammation. The aims of this study were to measure the association between anxiety and depressive symptoms, cardiovascular risk factors, and inflammatory markers. Outpatients aged 40 years or more undergoing colonoscopy after positive fecal occult blood test were enrolled; the following data were collected: body mass index, blood pressure, blood glucose, lipid profile, C-reactive protein (CRP) level, carotid thickness, Hospital Anxiety and Depression Scale, Temperament and Character Inventory, INTERdisciplinary MEDicine Self-Assessment, and 36-Item Short-Form Health Survey scores. Fifty-four patients were enrolled; 30.2% had anxiety symptoms, 18.9% depressive symptoms, and 9.4% concomitant anxiety-depressive symptoms. Anxiety symptoms were associated with low high-density lipoprotein levels. Depressive symptoms were associated with CRP levels, providing supporting evidence for the role of inflammation in the pathophysiology of depression.

LonP1 Differently Modulates Mitochondrial Function and Bioenergetics of Primary Versus Metastatic Colon Cancer Cells.

Mitochondrial Lon protease (LonP1) is a multi-function enzyme that regulates mitochondrial functions in several human malignancies, including colorectal cancer (CRC). The mechanism(s) by which LonP1 contributes to colorectal carcinogenesis is not fully understood. We found that silencing LonP1 leads to severe mitochondrial impairment and apoptosis in colon cancer cells. Here, we investigate the role of LonP1 in mitochondrial functions, metabolism, and epithelial-mesenchymal transition (EMT) in colon tumor cells and in metastasis. LonP1 was almost absent in normal mucosa, gradually increased from aberrant crypt foci to adenoma, and was most abundant in CRC. Moreover, LonP1 was preferentially upregulated in colorectal samples with mutated p53 or nuclear ß-catenin, and its overexpression led to increased levels of ß-catenin and decreased levels of E-cadherin, key proteins in EMT, in vitro. LonP1 upregulation also induced opposite changes in oxidative phosphorylation, glycolysis, and pentose pathway in SW480 primary colon tumor cells when compared to SW620 metastatic colon cancer cells. In conclusion, basal LonP1 expression is essential for normal mitochondrial function, and increased LonP1 levels in SW480 and SW620 cells induce a metabolic shift toward glycolysis, leading to EMT.

Metformin Induces Apoptosis and Alters Cellular Responses to Oxidative Stress in Ht29 Colon Cancer Cells: Preliminary Findings.

Accumulating evidence suggests that metformin, used as an antidiabetic drug, possesses anti-cancer properties. Metformin reduced the incidence and growth of experimental tumors in vivo. In a randomized clinical trial among nondiabetic patients, metformin treatment significantly decreased the number of aberrant crypt foci compared to the untreated group with a follow-up of 1 month. In our study, HT29 cells were treated with graded concentrations of metformin, 10 mM/25 mM/50 mM for 24/48 h. We performed immunofluorescence experiments by means of confocal microscopy and western blot analysis to evaluate a panel of factors involved in apoptotic/autophagic processes and oxidative stress response. Moreover, HT29 cells treated with metformin were analyzed by a flow cytometry assay to detect the cell apoptotic rate. The results demonstrate that metformin exerts growth inhibitory effects on cultured HT29 cells by increasing both apoptosis and autophagy; moreover, it affects the survival of cultured cells inhibiting the transcriptional activation of Nuclear factor E2-related factor 2 (NRF-2) and nuclear factor-kappa B (NF-κB). The effects of metformin on HT29 cells were dose- and time-dependent. These results are very intriguing since metformin is emerging as a multi-faceted drug: It has a good safety profile and is associated with low cost and might be a promising candidate for the prevention or the treatment of colorectal cancer.

Risk of colorectal polyps and of malignancies in asymptomatic carriers of mutations in the main DNA mismatch repair genes.

OBJECTIVE: Mutation carriers (Mut+) in DNA mismatch repair genes are predisposed to cancer of various organs and to adenomatous polyps; however, they may remain asymptomatic and cancer or polyp-free for several years. We purposed to analyse the clinical follow-up of individuals carrying constitutional mutations in the MLH1, MSH2 or MSH6 genes who were unaffected by benign polyps or malignant tumours at diagnosis. MATERIAL AND METHODS: Mut + subjects (n.81) were members of Lynch syndromes in whom mutations were detected between 1993 and 2015; all were asymptomatic at diagnosis. They were informed of the cancer risk and surveillance was suggested. As controls, 113 nongene carriers (Mut-) in the same Lynch families were identified. RESULTS: About one-fourth of the mutation carriers developed polyps, mostly adenomas; polyps were less (12%, p < .05) in Mut - subjects, and hyperplastic lesions were the prevalent histology. More polyps were detected in MLH1 vs. MSH2 mutation carriers. In Mut+, 21 malignant tumours developed in 14 carriers vs. 4 tumours in 3 patients among Mut- (p < .001). Tumours were mostly of the Lynch spectrum; however, three glioblastomas were developed, together with neoplasms of various organs (duodenum, thyroid, skin, lung and cervix). Mean age of tumour occurrence was 43.0 years in Mut + vs. 53.0 among Mut-. CONCLUSIONS: Cancer developed more often in Mut+, with no consistent difference between MLH1 and MSH2 carriers. More polyps (mostly adenomas) were detected in MLH1 carriers. The majority (13 of 21) of malignant tumours occurred in organs for which there is no recommended surveillance, and were lethal in three patients.

Attenuated adenomatous polyposis of the large bowel: Present and future.

Attenuated adenomatous polyposis (AAP) is a poorly understood syndrome, that can be defined as the presence of 10-99 synchronous adenomas in the large bowel, and it is considered a phenotypic variant of familial adenomatous polyposis (FAP). This definition has the advantage of simplicity, but it may include sporadic multiple adenomas of the large bowel at an extreme, or FAP cases on the other side. AAP shows a milder phenotype than FAP, with an older age of onset of adenomas and cancer, and less frequent extracolonic manifestations. AAP may be diagnosed as a single case in a family or, less frequently, it may be present in other family members, and it shows distinct pattern of inheritance. In less than 50% of cases, it may be caused by adenomatous polyposis coli (APC) or MUTYH mutations, referred to as APC-associated polyposis, inherited as an autosomal dominant trait, or MUTYH-associated polyposis, which shows an autosomal recessive mechanism of inheritance, respectively. Surveillance should rely on colonoscopy at regular intervals, with removal of adenomas and careful histological examination. When removal of polyps is not possible or advanced lesions are observed, the surgical approach is mandatory, being subtotal colectomy with ileo-rectal anastomosis the treatment of choice. Studies on this syndrome are lacking, and controversies are still present on many issues, thus, other clinical and genetic studies are requested.

Role of the Vanins-Myeloperoxidase Axis in Colorectal Carcinogenesis.

The presence of chronic inflammation in the colonic mucosa leads to an increased risk of cancer. Among proteins involved in the regulation of mucosal inflammation and that may contribute both to structural damage of the intestinal mucosa and to intestinal carcinogenesis, there are myeloperoxidase (MPO) and vanins. The infiltration of colonic mucosa by neutrophils may promote carcinogenesis through MPO, a key enzyme contained in the lysosomes of neutrophils that regulates local inflammation and the generation of reactive oxygen species (ROS) and mutagenic species. The human vanin gene family consists of three genes: vanin-1, vanin-2 and vanin-3. All vanin molecules are pantetheinases, that hydrolyze pantetheine into pantothenic acid (vitamin B5), and cysteamine, a sulfhydryl compound. Vanin-1 loss confers an increased resistance to stress and acute intestinal inflammation, while vanin-2 regulates adhesion and transmigration of activated neutrophils. The metabolic product of these enzymes has a prominent role in the inflammation processes by affecting glutathione levels, inducing ulcers through a reduction in mucosal blood flow and oxygenation, decreasing local defense mechanisms, and in carcinogenesis by damaging DNA and regulating pathways involved in cell apoptosis, metabolism and growth, as Nrf2 and HIF-1α.

Myeloperoxidase expression in human colonic mucosa is related to systemic oxidative balance in healthy subjects.

OBJECTIVES: To improve understanding of the preclinical stage of colonic inflammation by exploring the existence of a link between early inflammatory changes in the colonic mucosa and the systemic redox balance. METHODS: Clinical characteristics, a fasting blood draw, and mucosal biopsies from the right, left, and sigmoid-rectum colonic tracts collected from 28 healthy individuals (14/14 males/females) who underwent colonoscopy. Myeloperoxidase (MPO) positive cells infiltrating colonic mucosa specimens were assessed by immunohistochemistry, and patients divided into high or low MPO expressing cells/optical field groups (MPOhigh or MPOlow, respectively).The systemic oxidative balance has been studied through derived-Reactive Oxygen Metabolites (d-ROMs), Biological Antioxidant Potential (BAP), and Lipoperoxide-cholesterol Oxidizing (LP-CHOLOX) tests on serum. RESULTS: MPOhigh patients demonstrated an increased systemic oxidative stress compared to MPOlow individuals (P = 0.035), especially when MPO is referred to the left-sided colonic mucosa (P = 0.007). MPOlow subjects in the sigmoid-rectum showed a significant higher antioxidant capacity in the serum (P < 0.02). Sex-specific differences in MPO expression (male and female: 4.6 ± 3.2 and 2.6 ± 1.5 MPO-positive cells/optical field, respectively, P = 0.044), and a decreasing gradient in MPO expression moving from the cecum to the rectum (ascendant, descendant, and sigmoid-rectum: 3.7 ± 2.8, 3.1 ± 1.7, and 1.4 ± 0.5, respectively, P = 0.012) were also found and discussed. DISCUSSION: The study is the first demonstrating a connection between systemic redox balance and MPO expression in the colonic mucosa, according to the colonic tract and patient gender. Further research evaluating the MPO expression in the human colon and its relationship with pathological conditions could benefit from these results.

Attenuated polyposis of the large bowel: a morphologic and molecular approach.

Attenuated polyposis could be defined as a variant of familial adenomatous polyposis (FAP) in which synchronous polyps of the large bowel range between 10 and 99. We analysed all cases of attenuated polyposis observed over the last 30 years with the objectives: (A) to classify the disease according to different type and proportion of polyps; (B) To ascertain the contribution of APC and MutYH genes; (C) to discover features which could arise the suspicion of mutations; (D) To obtain indications for management and follow-up. 84 individuals in 82 families were studied. Polyps were classified into four groups as adenoma, hyperplastic, other serrated lesions or others; APC and MutYH mutations were assessed. Mean age at diagnosis was 54 ± 14 years in men and 48 ± 13 in women (P = 0.005). Polyps were more numerous in women (37 ± 26 vs 29 ± 22). Sixty % of patients underwent bowel resection, mainly for cancer; the remaining were managed through endoscopy. A total of 2586 polyps were detected at diagnostic endoscopy: 2026 (80 %) were removed and analysed. Adenomas were diagnosed in 1445 (70 %), hyperplastic polyps in 541 (26 %), other serrated lesions in 61 (2.9 %). Adenomas and hyperplastic lesions were detected in the majority of patients. In 68 patients (81 %) in whom studies were executed, APC mutations were found in 8 and MutYH mutations in 10. Genetic variants were more frequent in women (12 vs 6, P = 0.039). Taking into consideration the prevalent (>50 %) histology and presence of mutations, patients could be subdivided into four groups: (1) APC mutated polyposis (AFAP), when adenomas were >50 % and APC mutations detected (no. 8, 10 %); (2) MutYH mutated polyposis (MAP), adenomas >50 % and biallelic MutYH mutations (no. 10, 12 %); (1) attenuated polyposis without detectable mutations, prevalence of adenomas, 48 cases (57 %); (1) hyperplastic-serrated polyposis, with prevalence (>50 %) of hyperplastic/other serrated lesions and no constitutional mutation (no. 18, 21 %). Aggregation of tumors, cancer in probands, distribution of polyps and other clinical characteristics showed no difference among the four groups. In conclusions, AFAP and MAP, the polyposis labeled by constitutional mutations, represented about 25 % of all attenuated polyposis. Mutation-associated cases showed an earlier age of onset of polyps and were more frequent in the female sex.

Prevention of colorectal cancer: How many tools do we have in our basket?

Prevention is the main strategy in order to reduce colorectal cancer incidence and mortality. It can be accomplished through primary prevention, using measures affecting factors known to confer higher risk of colorectal cancer, or through secondary prevention, aimed at early diagnosis of cancer or preneoplastic lesions in groups of subjects at increased risk of cancer. Although primary prevention should be the goal for future years, because it acts on the probable causes of colorectal cancer, at present it seems that secondary prevention is more effective on colorectal cancer survival, and the approaches which have yielded the most satisfying results, in terms of reduced mortality for cancer, are those aimed at detecting preneoplastic lesions, or cancer at an early stage in selected groups of subjects at average or increased risk of colorectal cancer. These groups are subjects aged 50years or older, affected individuals (gene carriers) or family members of hereditary colorectal cancer syndromes (i.e., Lynch syndrome and familial adenomatous polyposis), and patients with inflammatory bowel diseases. The most effective procedures used, though with some drawbacks, are fecal occult blood tests and colonoscopy. Future research should be addressed to find new approaches that will render preventive strategies more acceptable for the population, and more cost-effective.

Autophagy is upregulated during colorectal carcinogenesis, and in DNA microsatellite stable carcinomas.

Cancer cells are exposed to a wide range of stress sources, such as nutrient deprivation and hypoxia, as well as cytotoxic chemotherapy and radiotherapy. Certain forms of stress can also promote survival activating the metabolic autophagy pathway in cancer cells. Autophagy is dramatically increased in cancer cells. In these conditions, it is becoming evident that autophagy protects cells, by providing an alternative energy source and by eliminating dysfunctional organelles or proteins. Its role in tumorigenesis is more controversial and both the presence and the absence of autophagy have been implicated. Autophagy is known to be associated with the poor outcome of patients with various types of cancers, and its effectiveness as a prognostic marker in colorectal cancer was demonstrated by several studies. The inhibition of autophagy may be a potential therapeutic target in colorectal cancer. In vitro experiments have shown that the inhibition of autophagy increases 5-FU-induced apoptosis. There are two trials currently investigating the addition of chloroquine to 5-FU-based chemotherapy and bevacizumab. In the present study, we evaluated the expression of LC3B-II in samples of human colorectal microadenomas (i.e., dysplastic aberrant crypt foci) and carcinomas compared to normal mucosa. Furthermore, the expression pattern of LC3B-II was assessed in carcinomas classified as DNA microsatellite stable (MSS) and unstable (MSI). Thus, immunofluorescence techniques coupled with confocal microscopy and immunoblot experiments were performed. The results clearly showed a significant increase in expression of the autophagic key factor in microadenomas and carcinomas with respect to normal mucosa. In MSS carcinomas, the level of LC3B-II expression was higher than that in the MSI carcinomas.