Polyp surveillance

Identification of key candidate genes and pathways associated with colorectal aberrant crypt foci-to-adenoma-to-carcinoma progression

AIM

The present study aimed to detect key candidate genes and pathways involved in colorectal aberrant crypt foci-to-adenoma-to-carcinoma progression.

BACKGROUND

Although colorectal cancer (CRC) is the third most common type of cancer, the involved signaling pathways and driver-genes remain largely unclear. CRC begins with the malignant transformation of precancerous lesions including aberrant crypt foci (ACF) and benign adenomatous polyp or adenoma.

METHODS

A list of formerly reported ACF, adenoma, and CRC-associated proteins was obtained from GeneCards, and then the data in online David Bioinformatics Resources was analyzed. The protein-protein interactions were surveyed utilizing String database and Cytoscape software. After hubs and bottlenecks were recognized, the key genes and pathways were identified through different bioinformatics analysis.

RESULTS

The most important pathways associated with colorectal aberrant crypt foci-to-adenoma progression were attributed to "pathways in cancer" and "chemokine signaling pathway" and those in adenoma-to-carcinoma progression were related to "pathways in cancer," "chemokine signaling pathway," and "Ras signaling pathway." The genes participating in these pathways are key ones. Furthermore, PRKACB, CUL2, and GSK3B were significant as the seed in the clusters related to adenoma and GNB1, RALBP1, ROCK1, and IKBKG in the clusters related to cancer.

CONCLUSION

The key candidate genes and pathways in progress CRC formed precursor lesions were identified by integrated bioinformatics analysis. The results could lead to a better understanding of the cause and underlying molecular events as well as detection of therapeutic targets for CRC.

Detection of intestinal cancer by local, topical application of a quenched fluorescence probe for cysteine cathepsins

Early detection of colonic polyps can prevent up to 90% of colorectal cancer deaths. Conventional colonoscopy readily detects the majority of premalignant lesions, which exhibit raised morphology. However, lesions that are flat and depressed are often undetected using this method. Therefore, there is a need for molecular-based contrast agents to improve detection rates over conventional colonoscopy. We evaluated a quenched fluorescent activity-based probe (qABP; BMV109) that targets multiple cysteine cathepsins that are overexpressed in intestinal dysplasia in a genetic model of spontaneous intestinal polyp formation and in a chemically induced model of colorectal carcinoma. We found that the qABP selectively targets cysteine cathepsins, resulting in high sensitivity and specificity for intestinal tumors in mice and humans. Additionally, the qABP can be administered by either intravenous injection or by local delivery to the colon, making it a highly valuable tool for improved detection of colorectal lesions using fluorescence-guided colonoscopy.

Streptococcus infantarius and carcinogenesis: a new chapter in colorectal pathology

As mirrored by several topics throughout history, the causal link between infectious diseases and cancer was initially viewed with disbelief and subsequently forgotten, only to be rediscovered decades later, when it started flourishing into a vibrant multidisciplinary field . Just a few years ago, it was estimated that over 20% of all cancers are causally linked to infectious diseases, most frequently caused by bacteria, viruses, and parasites .

Multicentric GISCoR Study "intensive clinical follow-up versus surgical radicalization after complete endoscopic polypectomy of a malignant adenoma" (SEC-GISCoR)

Colorectal cancer screening programs result in an early diagnosis of the disease. In 2007, 250 malignant polyps were identified in Lombardy, out of 1,329 screen-detected colorectal carcinomas. The Italian Group for Colorectal Cancer (GISCoR) promoted the multicentric study "Endoscopic Follow-up versus Surgical Radicalization of Malignant Polyps after Complete Endoscopic Polypectomy" (SEC-GISCoR). The protocol was a multicentric, prospective, observational, non-randomized study. It included patients diagnosed a colorectal malignant adenoma, after complete endoscopic removal. From November 2005 to September 2009, three participating centers enrolled 120 patients with malignant polyps after "complete" endoscopic polypectomy; malignant polyps were classified as "low risk" or "high risk". The study had two arms: "Intensive follow-up" (42 patients: 32 with low-risk and 10 with high-risk polyps) and "Surgical radicalization" (78 patients: 5 with low-risk and 73 with high-risk polyps). Data were collected using an online CRF. Overall, 37/120 polyps (30.8%) were low risk and 83/120 (69.2%) were high risk. 42 out of 120 patients (35%) were enrolled in the "clinical follow-up" arm, while 78/120 (65%) entered the surgery arm. In 15 cases, patients were not enrolled in the correct arm, according to the criteria agreed upon before starting the study. There still is a high incidence (11.5%) of pathological mismatches. No clinical event was reported in 2.9 years of follow-up. In conclusion, some differences emerged in the management of patients with malignant polyps among participating centers (p < 0.001), mismatches can be explained by high surgical risk or patient's choice. Only in 5 cases (4.2%), did data analysis not allow to exactly determine the reason for a choice different from protocol criteria. The availability of new risk factors and the evidence of pathological mismatches confirmed the need for future studies on this issue.