Imprinting and colorectal cancer

Stress-Coping Humoral Glycolipids Produced by Mice Given Controlled Bathing Treatments

Mammalians have recognition-behavioral stress-coping neuronal module system followed by some humoral glycolipids. A sulfated Galbeta1-4GlcNAc-lipid promotes the serotonergic module regulating the emotional behaviors for not-wasting the physical strength; GalNAcalpha1-3GalNAc-lipid promotes the adrenergic module inducing the behaviors escaping from the uneasy situation, and sulfated Fucalpha1-2Gal-lipid protects the cholinergic module keeping the stressor-memory from the ischemia-stress. Mouse given bathing recognizes the stressors to be coped with in the treatment. We previously observed mouse given CO₂-microbubble-bathing increased the behavior escaping from the bathing situation. Mouse given CO₂-microbubble-bathing would recognize the other stressors to be coped with in the treatment. We examined stress-coping glycolipids produced by mice given controlled bathing treatments, and got the following results. A sulfated Galbeta1-4GlcNAc-lipid production was increased by the acidic bathing condition and the dissolved CO₂, GalNAcalpha1-3GalNAc-lipid production was increased by the dissolved CO₂, and sulfated Fucalpha1-2Gal-lipid production was increased by the acidic bathing condition. We understood the mice treated with CO₂-microbubble-bathing would recognize the acidic bathing condition and the dissolved CO₂, but not the microbubble, as the other stressors to be coped.

Biology of colorectal cancer

Colorectal cancer is a serious health problem, a challenge for research, and a model for studying the molecular mechanisms involved in its development. According to its incidence, this pathology manifests itself in three forms: family, hereditary, and most commonly sporadic, apparently not associated with any hereditary or familial factor. For the types having inheritance patterns and a family predisposition, the tumours develop through defined stages ranging from adenomatous lesions to the manifestation of a malignant tumour. It has been established that environmental and hereditary factors contribute to the development of colorectal cancer, as indicated by the accumulation of mutations in oncogenes, genes which suppress and repair DNA, signaling the existence of various pathways through which the appearance of tumours may occur. In the case of the suppressive and mutating tracks, these are characterised by genetic disorders related to the phenotypical changes of the morphological progression sequence in the adenoma/carcinoma. Moreover, alternate pathways through mutation in BRAF and KRAS genes are associated with the progression of polyps to cancer. This review surveys the research done at the cellular and molecular level aimed at finding specific alternative therapeutic targets for fighting colorectal cancer.

Priorities in colorectal cancer research: recommendations from the Gastrointestinal Scientific Leadership Council of the Coalition of Cancer Cooperative Groups

Emerging technologies have greatly expanded our ability to detect, characterize, and treat colorectal cancer. The Coalition of Cancer Cooperative Groups convened a multidisciplinary panel, the Scientific Leadership Council in GI cancer, to discuss and advise on the priorities and opportunities to advance current and future approaches into the clinical arena to impact most rapidly the morbidity and mortality from this disease. The Council's recommendations for research priorities are the result of engagement of community and academic oncologists, patient advocacy groups, and other stakeholders including the pharmaceutical industry and governmental agencies. We detail some key prospects for investigation in the areas of colon cancer detection, prevention, and surgical and medical management. Many are in early or definitive clinical trials, and a focus on rapid accrual is urged. The implementation of biology-directed laboratory investigations, both in association with ongoing clinical trials and as a separate developmental strategy for targeted therapies, is supported as the route to individualized therapy.

Microsatellite instability

Unlike aneuploidy, considered to be the cardinal feature of malignant tumors ever since the chromosomal analysis of neoplastic cells became technically feasible, a second pathway toward malignancy has emerged over the past decade that is not characterized by gross aneuploidy but, instead, by inactivation of the DNA mismatch repair system, leading to a hypermutable state in which simple repetitive DNA sequences are unstable during DNA replication. Although mutations of many of these microsatellite sequences are presumably innocuous, because they do not occur in the coding or regulatory regions of genes, other such sequences are critically located in the coding regions of genes involved in the regulation of cell growth. First discovered in the rather uncommon hereditary nonpolyposis colorectal cancer syndrome, where there is an inactivating germline mutation in one of the DNA mismatch repair genes and most of the tumors show microsatellite instability, the latter phenomenon has since been implicated in about 15% of sporadic colorectal cancers, as well as in cancers at several other sites, such as the endometrium. Tumors showing microsatellite instability are generally near-diploid, are at a low stage of development, have a favorable prognosis, and, in the colon, are commonly located on the right side. In recent years, epigenetic phenomena, including hypermethylation and loss of imprinting, have come to be recognized as having a significant bearing on the development of these tumors.

Resolving the molecular mechanisms of radiation tumorigenesis: past problems and future prospects

Major goals in experimental radiobiology continue to be the resolution of the fundamental mechanisms of cellular radiation response and to gain detailed understanding of the contribution made by these responses to the complex in vivo processes of tumor development. The coupling of this framework of fundamental knowledge to epidemiological measures of risk greatly strengthens the biological basis of radiological protection. A selective overview is provided of recent advances in the understanding of the mechanisms and genetics of radiation tumorigenesis and their possible implications. It is suggested that rapid technical and academic advances in biology greatly expand the opportunities to further refine scientific knowledge on tumor risk after radiation.

Patched target Igf2 is indispensable for the formation of medulloblastoma and rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children (Dagher, R., and Helman, L. (1999) Oncologist 4, 34-44), whereas medulloblastoma, a highly malignant tumor of the cerebellum, accounts for 20% of childhood brain tumors (Goodrich, L. V., and Scott, M. P. (1998) Neuron 21, 1243-1257). Both tumors are associated with a deficiency in the tumor suppressor Patched (PTCH) in Gorlin syndrome (Gorlin, R. J. (1987) Medicine (Baltimore) 66, 98-113), and they are present in the corresponding murine models. RMS in Ptch mutant mice consistently contain elevated levels of the tumor growth-promoting insulin-like growth factor 2 (Igf2). We have investigated the mechanism of Igf2 overexpression and its significance in medulloblastoma and RMS tumorigenesis. Here we report that Igf2 is indispensable for the formation of medulloblastoma and RMS in Ptch mutants. Overexpression of Igf2 in RMS in these mice does not involve loss of imprinting, uniparental disomy, amplification of the Igf2 locus, or polyploidy. Since Igf2 is also overexpressed in non-tumor tissue deficient in Ptch, these observations suggest that Ptch regulates Igf2 levels through a transcriptional mechanism. They also identify Igf2 as a potential target for medulloblastoma and RMS.