Biophenotypes and survival of BRCA1 and TP53 deleted breast cancer in young women.

The aim of this study was to examine the loss of heterozygosity (LOH) of BRCA1 (17q21) and TP53 (17p13.1) in early-onset breast cancer patients; to correlate biopathological characteristics with molecular alterations; and to investigate the survival of LOH-related cancers. BRCA1 and TP53 LOH were evaluated in 78 early-onset breast cancers (< or = 40 years, Group 1) and 80 patients with age > 55 years (Group 2). Cases were characterized for multiple biological markers (ER, PR, proliferation index (PI), NEU and p53). LOH was carried out on microdissected paraffin embedded tissues; microsatellites D17S855 (BRCA1) and D17S786 (TP53) were amplified by fluorescent PCR and analyzed by an automated DNA sequencer. Early-onset breast cancers showed a higher frequency of ductal histotype (89.7% vs. 56.3% p < 0.001), node-positive (53.8% vs. 38.7%), larger size (p = 0.017), higher mitotic rate (p = 0.025), higher nuclear and final grade (p = 0.01 and p = 0.001, respectively). D17S855 LOH was 32.8% in group 1 vs. 21% in group 2; D17S786 LOH was 50.7% vs. 31.3% (p = 0.03), respectively. BRCA1 LOH was correlated with higher PI (p = 0.032) and higher p53 expression (p < 0.001) in group 1 and with higher NEU expression (p = 0.028) in group 2. TP53 LOH was correlated with p53 overexpression (p = 0.03) in group 1. A worse clinical outcome in early-onset LOH related cancers emerged from follow-up data: TP53 and BRCA1 LOH were associated with a shorter relapse free interval (RFI) (p = 0.03) and a poorer overall survival (OS) (p = 0.04), respectively. This study underlines different biological profiles in the two age groups investigated, probably reflecting different mechanisms of carcinogenesis. In accordance with adverse histopathological features in early-onset patients, LOH-related cancers have an unfavorable prognosis.

Sporadic colorectal adenocarcinomas with high-frequency microsatellite instability.

BACKGROUND: Widespread microsatellite instability (MSI) occurs in nearly 15% of sporadic colorectal cancers. Large bowel carcinomas with high-frequency MSI (MSI-H) (instability at > or = 30% of microsatellite loci) are believed to display distinctive pathologic features and to behave less aggressively than microsatellite-stable (MSS) tumors and carcinomas with low-frequency MSI (MSI-L) (instability at < 30% of microsatellite loci). The aim of the current study was to accurately define the clinicopathologic and biologic features of MSI-H sporadic colorectal carcinomas. METHODS: MSI status was evaluated in 216 large bowel adenocarcinomas using polymerase chain reaction (PCR) and 6 microsatellite markers. Tumors that showed instability with at least two microsatellite markers were classified as MSI-H, whereas the other tumors were classified as MSI-L (instability at one locus) or MSS (no instability). Expression of p53, hMLH1, and hMSH2 gene products was determined by immunohistochemistry, and DNA ploidy pattern was determined by flow cytometry. The prognostic significance of MSI status was assessed by univariate and multivariate survival analyses. RESULTS: The significantly different pathologic features of MSI-H carcinomas were proximal location; large size; mucinous and medullary histotype; poor differentiation; expanding pattern of growth; more frequent Crohn-like conspicuous lymphoid reaction; and low incidence of extramural vein invasion. Most MSI-H tumors were DNA diploid (33 of 40 tumors; 82.5%) and p53 negative (34 of 44 tumors; 77.3%). Conversely, DNA aneuploidy and p53 overexpression were observed in 82.3% (130 of 158 tumors; P < 0.0001) and 54.1% (93 of 172 tumors; P = 0.0002) of MSI-L/MSS tumors, respectively. Loss of hMLH1 or hMSH2 expression was detected in a high fraction of MSI-H carcinomas (86. 0%). Patients with MSI-H tumors showed a better clinical outcome than patients with MSI-L/MSS tumors (P = 0.0017). Furthermore, in multivariate analysis that included conventional clinicopathologic parameters, MSI status, and p53 expression as covariates, MSI status was a significant independent prognostic indicator of disease specific survival. CONCLUSIONS: Assessment of MSI status is an essential step in the genetic characterization of large bowel carcinomas and identifies a subset of tumors with distinct clinical, pathologic, and biologic features.

Mole maker phenotype: possible narrowing of the candidate region.

Recent data has suggested that familial recurrent hydatidiform mole is a rare autosomal recessive trait in women experiencing this gestational disease (MIM 231090). Here we provide molecular data on an additional family confirming that recurrent familial hydatidiform moles are diploid, biparental and arise from independent conceptions. A narrowing of the gene interval on chromosome 19q13.3-13.4 is suggested by haplotype analysis in two sisters.

Chromosome 18q allelic loss and prognosis in stage II and III colon cancer.

The prognostic significance of chromosome 18q allelic loss was evaluated in a series of 118 patients with curatively resected TNM stage II or stage III colon cancer. Chromosome 18q status was determined on frozen tumour samples, using microsatellite markers and the polymerase chain reaction (PCR). Mean follow-up in surviving patients was 75.9 months. Chromosome 18q allelic loss was significantly related to tumour site, extramural venous invasion, flow cytometric nuclear DNA content and p53 protein expression. Patients whose tumour had no evidence of chromosome 18q allelic loss showed a better disease-free and overall survival than patients whose tumour demonstrated 18q allelic loss. When patients were stratified by tumour stage, a significant survival advantage for patients whose tumour had no allelic loss on chromosome 18q was observed in stage II as well as in stage III disease. In particular, patients with stage II disease whose tumour had no chromosome 18q allelic loss demonstrated an excellent clinical outcome, with a 5-year disease-free survival rate of 96%. In contrast, the 5-year disease-free survival rate of patients with stage II disease and chromosome 18q allelic loss was only 54%. In multivariate analysis, status of chromosome 18q was the only significant independent prognostic factor for both disease-free and overall survival. These results indicate that assessment of chromosome 18q status provides relevant prognostic information in colon cancer and might be employed in the selection of patients for adjuvant therapy.

Prognostic significance of DNA ploidy in patients with stage II and stage III colon carcinoma: a prospective flow cytometric study.

BACKGROUND: The prognostic value of flow cytometric DNA ploidy in colorectal carcinoma has not been defined clearly. Most previous studies were conducted retrospectively using archival formalin fixed, paraffin embedded tumor samples. Conversely, few data on prospective studies employing fresh or frozen tissue specimens are available. There is general agreement that fresh/frozen material is more reliable than paraffin embedded tissue for DNA ploidy analysis by flow cytometry. METHODS: In the current investigation we evaluated the prognostic significance of nuclear DNA content in a prospective series of 191 patients with curatively resected TNM Stage II (n = 107) or Stage III (n = 84) sporadic colon carcinomas. DNA ploidy status was assessed by flow cytometry utilizing multiple frozen tumor samples. Mean follow-up in surviving patients was 48.5 months (median, 46.9 months; range, 29-77 months). The Cox proportional hazards model was used to adjust for several clinical and pathologic covariates. RESULTS: Of the 191 carcinomas examined, 47 (24.6%) were classified as DNA diploid and 144 (75.4%) as DNA aneuploid. DNA ploidy pattern was significantly related to tumor site (P < 0.0001), histologic type (P = 0.0002), and grade of differentiation (P = 0.009), but not to other clinical and pathologic variables. Patients with DNA diploid tumors showed a better disease free (P = 0.013) and overall survival (P = 0.021) than patients with DNA aneuploid adenocarcinomas. In particular, patients with Stage II DNA diploid tumors (n = 30) had an excellent clinical outcome, with an overall 5-year survival rate of 97%. When patients were analyzed according to the anatomic site of the tumor, a significant relationship between DNA ploidy status and disease free and overall survival was observed in the group of patients with carcinomas of the proximal colon (n = 84) (P = 0.004 and P = 0.002, respectively), but not among patients whose tumors were sited distally to the splenic flexure (n = 107). In multivariate analysis, nuclear DNA content was demonstrated to be an independent prognostic variable for both disease free and overall survival. Furthermore, in the group of patients with tumors of the proximal colon, DNA ploidy pattern was the single most important prognostic factor. CONCLUSIONS: Our results confirm that flow cytometric DNA ploidy status is a significant and independent prognostic factor in patients with colon carcinoma. These findings may have clinical implications for the management of affected patients, especially those with Stage II disease.

Inhibitory effect of dihydrotestosterone on human thyroid cell growth.

Sex steroid-binding activities have been identified by several authors in normal and pathological thyroids and the expression of the canonic androgen receptor (AR) has recently been demonstrated in human thyroid follicular cells. In order to assess what influence, if any, androgen exposure has on thyroid cell growth, the effect of dihydrotestosterone (DHT) on [3H]thymidine (thy) incorporation and cell proliferation was investigated in thyroid follicular cells in vitro. In a primary culture of goitrous cells, DHT induced a significant reduction of [3H]thy incorporation at concentrations ranging from 10(-12) to 10(-8) M, with a more pronounced effect at 10(-9) M. At this concentration, the inhibitory effect was evident after both 24 and 48 h of treatment and in various types of primary thyroid cell cultures. In goitrous cells, the DHT-induced decrease of [3H]thy was associated with a reduction of expression of the proliferation-associated nuclear Ki-67 antigen, a protein commonly used to assess cell growth fraction. In TPC cells, an AR-positive thyroid papillary carcinoma cell line, DHT at concentrations between 10(-12) and 10(-8) M significantly decreased the growth rate. DHT (10(-9) M) produced an approximately 50-60% inhibition of cell proliferation and the antiandrogen cyproterone acetate was capable of reversing such effects. The DHT-induced reduction of TPC cell proliferation was associated with a significant reduction of c-myc RNA levels. Thyroperoxidase mRNA levels and thyroglobulin production were not reduced by androgen in primary cultures of goitrous cells. In conclusion, our results indicated that androgens may have a role in this gland by reducing the proliferation, but not the function, of follicular cells.

p53 expression in colorectal cancer: relation to tumor type, DNA ploidy pattern and short-term survival.

p53 protein expression was evaluated in a series of 204 primary colorectal adenocarcinomas by immunohistochemistry using frozen tissue sections and monoclonal antibody DO-7. Nuclear staining of more than 5% of neoplastic cells was observed in 124 (60.8%) adenocarcinomas, which were classified as p53 positive. p53 immunoreactivity was found to he unrelated to several clinical and pathologic variables, including age and sex of patient, tumor site, tumor stage, grade of differentiation, pattern of growth, degree of peritumoral lymphocytic infiltration, and venous invasion. A strong association was demonstrated between p53 immunostaining and tumor type. Only 4 of 21 mucinous carcinomas examined (19%) were p53 positive. Conversely, 120 of 183 (65.6%) nonmucinous adenocarcinomas showed positive p53 immunostaining (P <.0001). p53 expression also was related to the flow cytometric DNA ploidy pattern, aneuploid carcinomas with DI >1.20 showing higher frequency of p53 overexpression than DNA diploid, and aneuploid tumors with DI < or = 1.20 (P = .0003). No relationship was found between p53 expression and the Ki-67 proliferation index. With respect to the total study population (mean follow-up 33.4 months; range 19-47 months) the duration of overall survival was independent of p53 expression. In the group of 141 patients with stage I, stage II, and stage III disease who had undergone curative resection, positive p53 immunostaining was associated with poorer overall survival (P = .029). Subgroup analysis showed that the reduced survival conferred by p53 overexpression was confined to patients with stage III tumors (P = .027). However, in multivariate analysis, p53 expression failed to demonstrate independent prognostic significance. Our results indicate that immunohistochemical analysis of p53 expression provides valuable information for the understanding of colorectal cancer biology and clinical behavior.

Evidence for androgen receptor gene expression in human thyroid cells and tumours.

Androgen-binding activity has been identified in normal and pathological thyroids, but evidence for the expression of the canonic androgen receptor (AR) in the thyroid has not been provided so far. In this study we have used reverse transcription (RT)-PCR to examine RNA expression of the canonic AR gene in human thyroid tissues, in primary cultures of human thyrocytes and in a variety of neoplastic thyroid cell lines (NPA, TPC and WRO). An AR cDNA fragment with the expected size of 262 bp was detected in normal tissues and cultured thyrocytes as well as in neoplastic cell lines, demonstrating that the gene for AR is indeed expressed in thyroid follicular cells. Immunocytochemical analysis revealed the presence of the AR protein in cancer cell lines and androgen treatment increased nuclear positivity to AR. In a survey of 35 thyroid tissues AR cDNA was detected in all the non-neoplastic samples (6 normal and 3 goitrous) and in 19 of 26 neoplastic samples. AR cDNA was not detected in 4 of the 9 follicular adenomas and in 3 of the 12 papillary carcinomas. AR was revealed by immunohistochemistry in 1 of 2 normal thyroids, in 1 goiter and in 1 of 2 neoplastic thyroids. These findings show the presence of the canonic AR in the human thyroid.

[Clinico-pathological features and biological characterization of mucoid colorectal carcinoma]. / Aspetti clinico-pathologici e caratterizzazione biologica del carcinoma mucoide del colon-retto.

The clinical, pathological and biologic features of 79 mucinous colorectal carcinomas were compared with those of 602 non-mucinous adenocarcinomas. The two groups did not show appreciable differences in patients' age, stage distribution, extent of lymph node involvement, grade of differentiation, pattern of growth and venous invasion. Mucinous carcinomas occurred more frequently among female patients (P < 0.05) and in the proximal colon (P < 0.01). Moreover, mucinous carcinomas more often demonstrated origin within villous adenomas (P < 0.0001) and lacked pronounced peritumoural lymphocytic infiltration (P < 0.001). A strong association was found between tumour type and flow cytometric nuclear DNA content. A high proportion of mucinous carcinomas showed DNA index (DI) values < or = 1.20 (26/38, 68.4%); conversely only 103 of 322 (32%) non-mucinous carcinomas had a DI < or = 1.20 (P < 0.0001). In addition mucinous carcinomas were characterized by infrequent p53 overexpression (4/21, 19% versus 120/183, 65.6%; P < 0.001) and higher levels of proliferative activity (P < 0.0001) compared to non-mucinous adenocarcinomas. Our data support the hypothesis that mucinous carcinoma represents a distinct clinicopathologic and genetic entity.

Biologic characterization of hereditary non-polyposis colorectal cancer. Nuclear ploidy, AgNOR count, microvessel distribution, oncogene expression, and grade-related parameters.

The identification of hereditary non-polyposis colorectal cancer (HNPCC) is important not only for the patient, but also for family members who are at increased risk of developing cancer. To determine if measuring various pathobiologic features of the colon carcinomas is useful in separating sporadic from HNPCC tumors, the authors studied tumor tissues from 46 patients with HNPCC and compared them to 70 with sporadic colorectal carcinoma. Parameters investigated included DNA ploidy (flow cytometry), AgNOR count (by silver staining), microvessel density (immunohistochemistry), p53 and K-ras expression, and grade-related parameters. Diploid tumors were more frequent in patients with HNPCC (65% vs 40%, P < .02), thus confirming previous observations concerning such an association. Higher AgNOR counts and greater AgNOR areas were observed in sporadic tumors than in HNPCC (5.2 +/- 1.5 vs 4.5 +/- 1.8, P < .01). Hereditary tumors tended to be less vascularized, whereas oncogene expression and grade-related parameters did not show appreciable differences between the two types of tumors. In conclusion, some of the investigated parameters may contribute to defining the biologic profile of HNPCC. In addition, these findings support the clinical impression of a more favorable outcome that is frequently seen in HNPCC patients.

Androgen responsiveness and androgen receptor gene expression in human kidney cells in continuous culture.

The effects of androgen and estrogen on cell growth and gene expression were investigated in KJ29 kidney epithelial cells. Incorporation of 3H leucine and 3H thymidine was increased by androgen at 10nM, but not by estrogen. Estrogen however, inhibited the effects induced by androgen. In addition, cell number and the proliferation marker Ki67 were increased by androgen, but not by estrogen. Levels of androgen receptor RNA, as detected by RT-PCR and Northern blot analysis, were not affected by either androgen or estrogen. Levels of estrogen receptor RNA could be detected only by RT-PCR, and disappeared after estrogen treatment. These studies show that sex steroid receptors are differently expressed in KJ29 cells, and suggest that androgen, via its canonic receptor, acts as a mitogenic factor in human kidney cells, whereas estrogen has an antiandrogenic action.

[Evaluation of prognostic parameters in colorectal carcinoma. II. Ploidy determination with flow cytometry]. / Valutazione di parametri prognostici nel carcinoma del colon-retto. II.Ploidia mediante citometria a flusso.

The prognostic value of DNA ploidy in large bowel cancer is still controversial. In the present investigation we have evaluated the nuclear DNA content in 123 colorectal adenocarcinomas by flow cytometry using multiple frozen tumour samples. Thirty-three (26.8%) carcinomas were classified as diploid and 90 as aneuploid (73.2%). Presence of DNA aneuploidy was found to be unrelated to age and sex of patients, tumour stage and grade of differentiation, as well as to several other histopathological variables. However, multiploid tumours (20/123, 16.3%) resulted to be more frequently in advanced stages of disease (stages III and IV, P < 0.025) and more often showed unfavourable histopathological features, especially an infiltrating pattern of growth (P < 0.05), compared to diploid and single aneuploid carcinomas. Nuclear DNA content was found to be closely related to tumour site. Carcinomas of the proximal colon were more frequently diploid (P < 0.005) and more often displayed a DI < or = 1.20 (P < 0.001) than tumours of the distal colon. Nuclear DNA content was also found to be related to tumour type. In fact, a high proportion (66.7%) of mucinous carcinomas showed DI values < or = 1.20; conversely only 31.4% of nonmucinous adenocarcinomas had a DI < or = 1.20 (P < 0.01). Intratumoural heterogeneity in nuclear DNA content was found in 23% of cases. These results seem to suggest that the DNA ploidy pattern probably reflects different genetic mechanisms involved in the development of carcinomas in the proximal and distal colon. Furthermore our data support the hypothesis that mucinous carcinoma represents a distinct clinicopathologic entity, possibly related to pathogenetic factors different from those acting in the majority of nonmucinous adenocarcinomas. Finally, the analysis of multiple tissue samples taken from different areas of each tumour is necessary to assess carefully the DNA ploidy pattern of large bowel carcinomas.

Relationship of nuclear DNA content to clinicopathologic features in colorectal cancer.

Nuclear DNA content was determined in 123 colorectal adenocarcinomas by flow cytometry using multiple frozen tumor samples. Thirty-three (26.8%) carcinomas were classified as diploid and 90 as aneuploid (73.2%). Presence of DNA aneuploidy was found to be unrelated to tumor stage and grade of differentiation and to other histopathological variables such as pattern of growth, degree of peritumoral lymphocytic infiltration, and venous invasion. However, multiploid tumors (20/123, 16.3%) were more frequently noted in advanced stages of disease (Stages III and IV, P < 0.025) and more often showed unfavorable histopathological features, especially an infiltrating pattern of growth (P < 0.05), compared with diploid and single aneuploid carcinomas. Nuclear DNA content was found to be closely related to tumor site. Carcinomas of the proximal (right and transverse) colon were more frequently diploid (19/43, 44.2% versus 14/80, 17.5%--P < 0.005) and more often displayed a DNA index (DI, defined as the ratio of the DNA content of neoplastic cells to that of normal cells) < or = 1.20 (27/43, 62.8% versus 19/80, 23.7%--P < 0.001) than did tumors localized distally to the splenic flexure. Nuclear DNA content was also found to be related to tumor type. A high proportion of mucinous adenocarcinomas showed DI values < or = 1.20 (14/21, 66.7%); conversely only 32 of 102 (31.4%) non-mucinous adenocarcinomas had a DI < or = 1.20 (P < 0.01). The nuclear DNA content of mucinous adenocarcinomas seemed to be independent of tumor location.(ABSTRACT TRUNCATED AT 250 WORDS)

A c-myc gene variant without exon 1 and with an abnormal methylation pattern inherited in a woman with no evidence of malignancy.

A c-myc DNA with a deletion which includes 5' flanking, exon 1 and intron I sequences has been found in normal white blood cells of a mother and one daughter in a Northern Italian family. In addition, the degree of methylation of specific CCGG sites in the truncated DNA is lower in both mother and daughter than that found in normal DNA. It is of interest that deletions of the first exon and hypomethylation of the c-myc gene have usually been observed only in some neoplasias. However, our results demonstrate that the c-myc truncated DNA with the abnormal methylation pattern here reported is a genomic variant which by itself is not related to neoplastic transformation.

Different methylation of oestrogen receptor DNA in human breast carcinomas with and without oestrogen receptor.

The methylation of the human oestrogen receptor (ER) gene was analysed by restriction enzymes in normal and neoplastic human breast tissues and cell lines. CCGG sequences in regions inside the gene, which are methylated both in normal breast and in tissues that are not the target of the oestrogen, are hypomethylated in 30% of tumours, both ER+ and ER- carcinomas. Moreover, 5' sequences of the gene, which are hypomethylated in normal breast and not in tissues not the target of oestrogen, are methylated to a lower degree in ER+ carcinomas, whereas they are methylated to a greater degree in ER- carcinomas. However, the same region is equally hypomethylated in both ER+ and ER- cancer cell lines. Our results indicate that in breast carcinomas ER DNA methylation is deranged, and in cancer cell lines is different from that observed in primary tumours. Furthermore, the abnormal methylation in the 5' end seems to be related to abnormal expression, namely diffuse hypomethylation in carcinomas with high ER content and hypermethylation in carcinomas without ER. These findings support our previous hypothesis that DNA methylation could be involved in the control of ER gene expression and demonstrate that abnormal ER gene methylation is a typical feature of breast cancers.

[Effects of somatostatin on human thyroid folliculi in vitro]. / Effetti della somatostatina su follicoli tiroidei umani in vitro.

Somatostatin (SRIF) inhibits calcitonin and T3-T4 secretion in thyroid. We have investigated the in vitro effect of SRIF on the basal and TSH induced [3H]thy incorporation, thyroglobulin (tgb) RNA and cAMP level in follicular cells, isolated from normal and adenomatous human thyroids. [3H]thy uptake has been evaluated as TCA-precipitable material in 2, 4, 8, 24 h incubated follicles and 24 h incubated adherent cells. Tgb RNA has been quantified with cytoplasmic dot blot hybridization and cAMP level with RIA method. SRIF reduces basal and TSH-induced [3H]thy in both suspension follicles and epithelial adherent cells. However it does not modify tgb RNA nor cAMP levels in incubated follicles. These data suggest a direct antiproliferative effect of SRIF on human thyroid.

The methylation pattern in the 5' end of the human estrogen receptor gene is tissue specific and related to the degree of gene expression.

Restriction enzyme mapping has been used to study the relationship between methylation at the 5' end of the human estrogen receptor gene (ER) and its various levels of expression in estrogen target tissues, like endometrium, placenta and breast. The methylation patterns were compared with that found in white blood cells. A cluster of CpG sites, including the transcription start site, was undermethylated in all examined tissues. In front and downstream of this area, a 1 Kb region was undermethylated in endometrium where the ER gene is highly expressed, methylated to some extent in placenta and breast, which express the gene to a low degree, and greatly methylated in white blood cells which are thought not to express this gene. These data provide evidence that in the 5' end of the human ER DNA, CpG methylation is tissue-specific, and related to the level of the ER gene expression.

Differential hypomethylation of the c-myc protooncogene in bladder cancers at different stages and grades.

The 5-methylcytosine content of c-myc proto-oncogene DNA obtained from samples of normal bladders and of bladders with transitional cell carcinoma of different stage and grade was analyzed. Five CCGG sites (from the third coding region to the 3' flanking region of the gene) which showed different methylation in normal and neoplastic samples were identified. The overall c-myc methylation levels were significantly reduced in carcinomas. Furthermore, a significant correlation between disease invasiveness and methylation level was found. Nevertheless, in each group of patients with the same histological grade, heterogeneity has been observed. This might be suggestive of different prognosis of the disease.