ATRX loss in adult supratentorial diffuse astrocytomas correlates with p53 over expression and IDH1 mutation and predicts better outcome in p53 accumulated patients.

BACKGROUND: IDH1/2 mutation, 1p/19q-codeletion and MGMT hypermethylation are well known molecular markers for gliomas. ATRX and p53 alterations are two lineage-specific genetic aberrations in diffuse astrocytic tumors. The aim of the present study is to clarify the significance of ATRX loss and its correlation with p53 overexpression, IDH1/2 mutations, 1p/19q-codeletion and MGMT hypermethylation in supertentorial astrocytoma, and to determine the prognostic value of these factors in Chinese patients. METHODS AND RESULTS: A total of 135 adult supertentorial astrocytomas were evaluated. ATRX loss was detected by immunohistochemistry (IHC) and was shown to be much less frequent in pGBs (3.5%) than in grade II, III astrocytomas and IV sGBs (31%). Direct sequencing and/or IHC analysis of the IDH1R132H gene mutation and p53 accumulation demonstrated correlation with age. Strong correlations were found between ATRX loss and IDH1R132H mutation, p53 overexpression as well as MGMT hypermethylation. 1p/19q-codeletion detected by fluorescence in situ hybridization (FISH) showed mutually exclusive with ATRX loss and p53 accumulation. In addition, patients with p53 overexpression combined with ATRX alterations demonstrated substantially longer survival than patients with wild-type ATRX. CONCLUSIONS: There may be interactions among these distinct molecules in astrocytoma development. ATRX loss may predict better clinical outcome in astrocytoma patients with p53 overexpression as compared to patients with wild-type ATRX. Tumors with astrocytoma phenotype accompanied by 1p/19q-codeletion and IDH1R132H mutation are mutually exclusive with ATRX and p53 alterations. Routine IHC can be used for evaluation of ATRX loss, p53 protein accumulation and IDH1R132H mutation, which may allow a means of classification of astrocytoma outcome.

KRAS and BRAF gene mutations and DNA mismatch repair status in Chinese colorectal carcinoma patients.

AIM: To investigate gene mutations and DNA mismatch repair (MMR) protein abnormality in Chinese colorectal carcinoma (CRC) patients and their correlations with clinicopathologic features. METHODS: Clinical and pathological information for 535 patients including 538 tumors was reviewed and recorded. Mutation analyses for exon 2 of KRAS gene and exon 15 of BRAF gene were performed by Sanger sequencing except that in 9 tumors amplification refractory mutation system PCR was used. Expression of MMR proteins including MHL1, MSH2, MSH6 and PMS2 was evaluated by immunohistochemistry. Correlations of KRAS and BRAF mutation status and the expression status of MMR proteins with age, gender, cancer stage, location, and histology were analyzed. Correlations between KRAS or BRAF mutations and MMR protein expression were also explored. RESULTS: The overall frequencies of KRAS and BRAF mutations were 37.9% and 4.4%, respectively. KRAS mutations were more common in patients ≥ 50 years old (39.8% vs 22% in patients < 50 years old, P < 0.05). The frequencies of BRAF mutants were higher in tumors from females (6.6% vs males 2.8%, P < 0.05), located in the right colon (9.6% vs 2.1% in the left colon, 1.8% in the rectum, P < 0.01), with mucinous differentiation (9.8% vs 2.8% without mucinous differentiation, P < 0.01), or being poorly differentiated (9.5% vs 3.4% well/moderately differentiated, P < 0.05). MMR deficiency was strongly associated with proximal location (20.5% in the right colon vs 9.2% in the left colon and 5.1% in the rectum, P < 0.001), early cancer stage (15.0% in stages I-II vs 7.7% in stages III-IV, P < 0.05), and mucinous differentiation (20.2% vs 9.2% without mucin, P < 0.01). A higher frequency of MLH1/PMS2 loss was found in females (9.2% vs 4.4% in males, P < 0.05), and MSH2/MSH6 loss tended to be seen in younger (<50 years old) patients (12.0% vs 4.0% ≥ 50 years old, P < 0.05). MMR deficient tumors were less likely to have KRAS mutations (18.8% vs 41.7% in MMR proficient tumors, P < 0.05) and tumors with abnormal MLH1/PMS2 tended to harbor BRAF mutations (15.4% vs 4.2% in MMR proficient tumors, P < 0.05). CONCLUSION: The frequency of sporadic CRCs having BRAF mutation, MLH1 deficiency and MSI in Chinese population may be lower than that in the Western population.

Correlation of immunoglobulin G expression and histological subtype and stage in breast cancer.

INTRODUCTION: Recently, growing evidence indicates that immunoglobulins (Igs) are not only produced by mature B lymphocytes or plasma cells, but also by various normal cells types at immune privileged sites and neoplasm, including breast cancer. However, the association of breast cancer derived IgG with genesis and development of the disease has not yet been established. METHODS: In this study we examined the expression of IgG in 186 breast cancers, 20 benign breast lesions and 30 normal breast tissues. Both immunohistochemistry with antibodies to Igκ (immunoglobulin G κ light chain) and Igγ (immunoglobulin G heavy chain) and in situ hybridization with an antisense probe to IgG1 heavy chain constant region gene were performed. Various clinicopathological features were also analyzed. RESULTS: We found that IgG is specifically expressed in human breast cancer cells. Both infiltrating ductal carcinoma and infiltrating lobular carcinoma had significantly greater numbers of Igκ and Igγ positive cancer cells as compared with medullary carcinoma, carcinoma in situ, and benign lesions (all p<0.05). In addition, IgG expression was correlated with breast cancer histological subtypes (p<0.01) and AJCC stages (p<0.05), with more abundance of IgG expression in more malignant histological subtypes or in more advanced stage of the disease. CONCLUSIONS: IgG expression in breast cancer cells is correlated with malignancy and AJCC stages of the cancers. This suggests that breast cancer derived IgG may be associated with genesis, development and prognosis of the cancer.

IgG expression in human colorectal cancer and its relationship to cancer cell behaviors.

Increasing evidence indicates that various cancer cell types are capable of producing IgG. The exact function of cancer-derived IgG has, however, not been elucidated. Here we demonstrated the expression of IgG genes with V(D)J recombination in 80 cases of colorectal cancers, 4 colon cancer cell lines and a tumor bearing immune deficient mouse model. IgG expression was associated with tumor differentiation, pTNM stage, lymph node involvement and inflammatory infiltration and positively correlated with the expressions of Cyclin D1, NF-κB and PCNA. Furthermore, we investigated the effect of cancer-derived IgG on the malignant behaviors of colorectal cancer cells and showed that blockage of IgG resulted in increased apoptosis and negatively affected the potential for anchor-independent colony formation and cancer cell invasion. These findings suggest that IgG synthesized by colorectal cancer cells is involved in the development and growth of colorectal cancer and blockage of IgG may be a potential therapy in treating this cancer.

Quantitative morphometry by image analysis of normal, hyperplastic and cancerous ductal breasts.

OBJECTIVE: To analyze a number of quantitative variables in ductal epithelial breast proliferations and test them against diagnoses established by standard histologic and cytologic criteria in order to determine which variables are useful in discriminating between histologic diagnoses. STUDY DESIGN: A method was developed for the semiautomatic segmentation and quantitative analysis of breast ductal proliferations using image analysis. This permitted duct profiles and intraductal epithelial proliferations to be analyzed by computer, with calculation of a total of 17 variables--for example, nuclear/cytoplasmic ratio, nuclear circularity, average internuclear distance and lumen area. Four groups were analyzed employing a total of 80 cases with diagnoses established by standard histologic criteria, including normal breast duct (DN = 19 cases), ductal hyperplasia without atypia (DH = 21 cases), ductal carcinoma in situ (DCIS = 20 cases) and invasive ductal carcinoma (INV = 20 cases). RESULTS: Of the 17 quantitative variables tested in this study, 15 showed statistically significant differences in values between DH and DCIS (p < 0.05), and 7 showed statistically significant differences between DN and DH (p < 0.05). CONCLUSION: By quantitative morphometric analysis of selected variables, a significant statistical distinction can be made between diagnostic groups, paving the way for automatic computerized image recognition for differential diagnosis.