17 colorectal carcinomas without any adenoma component expressing both immunoreactive p53 and BGP protein were selected from 96 resected specimens from our previous study.
Increased cytoplasmic and/or nuclear beta-catenin staining was seen in 94% and 80% of the adenomas. beta-Catenin nuclear staining was strongly associated with MYC levels (p value 0.03) but not with KRAS mutations.Copy number aberrations were rare.
Although gene-to-gene analyses identified genetic alterations such as APC, KRAS and TP53 mutations in colon adenomas, it is largely unknown whether there are any others in them.
At last assessment (median follow-up 3 years) and compared with values 6-12 months after stopping DA, Prolactin (PRL) increased in 15%, decreased but not normalized in 33% and was normal in 52%; PRL levels or visible adenoma on imaging before DA withdrawal, treatment duration and presence of macro-/microadenoma at diagnosis were not predictors of normoprolactinaemia at last review, whereas PRL values 6-12 months after stopping DA were.
The aim of the study was to investigate if specific K-ras-2 mutations in 58 human sporadic adenomas were correlated with DNA aneuploidization and cell proliferation.
The APC promoter is hypermethylated in 18% of primary sporadic colorectal carcinomas (n = 108) and adenoma (n = 48), and neoplasia with APC methylation fails to express the APC transcript.
Forty-four GH-secreting adenomas, 7 prolactin (PRL)-secreting adenomas and 32 clinically non-functioning adenomas were examined for the presence of point mutations in codon 201 and 227 of the Gs alpha gene using a nested PCR and direct sequencing of DNA extracted from fresh tissue or paraffin-embedded pituitary adenoma samples.
While the effect of p53 mutations on colorectal cancer prognosis has been heavily studied, less is known about how epidemiologic risk factors relate to p53 status, particularly in early colorectal neoplasia prior to clinically invasive colorectal cancer (including adenomas, carcinoma in situ (CIS), and intramucosal carcinoma).
Germ-line APC mutations were detected in each of three unrelated cases of TS, and additional (somatic) mutations were observed in colonic adenomas that had developed in one of these patients.
Effects of the Janus Kinase Inhibitor, Tofacitinib, on Testicular Leydig Cell Hyperplasia and Adenoma in Rats, and on Prolactin Signaling in Cultured Primary Rat Leydig Cells.
An advanced invasive non-functioning adrenocortical carcinoma carried a somatic heterozygous BRAF V600E mutation, while 4 functioning and 4 non-functioning adenomas and 3 functioning carcinomas carried different CTNNB1 activating mutations.
The level of KCNJ5 mRNA in cortisol-producing adenomas was approximately 30% of that in APA, and almost no expression was observed in pheochromocytomas.
In general, BCL-2 expression was significantly stronger in the adenoma than in non-neoplastic mucosa and carcinoma, although there was no significant difference of ISTR-labeling between adenoma and carcinoma.
These findings suggest that, following APC loss, CtBP1 contributes to adenoma initiation as a first step, whereas KRAS activation and beta-catenin nuclear localization promote adenoma progression to carcinomas as a second step.
Cytokeratin 7 and especially cytokeratin 17 highlighted the presence of ducts in the hyperplastic lesion, which are not present in adenomas. p16 and p53 were negative and Ki-67 immunostaining demonstrated similar low proliferation indices for normal and hyperplastic glands.
These findings indicated that the K-ras gene mutations occur during the late stage of adenoma progression and may confer a more advanced morphological phenotype of adenoma, but these mutations are not mainly involved in malignant transformation from adenoma to carcinoma.