Caterina Pellegrini

Inhibitors of apoptosis proteins (IAPs) expression and their prognostic significance in hepatocellular carcinoma

BackgroundSimilarly to other tumor types, an imbalance between unrestrained cell proliferation and impaired apoptosis appears to be a major unfavorable feature of hepatocellular carcinoma (HCC). The members of IAP family are key regulators of apoptosis, cytokinesis and signal transduction. IAP survival action is antagonized by specific binding of Smac/DIABLO and XAF1. This study aimed to investigate the gene and protein expression pattern of IAP family members and their antagonists in a series of human HCCs and to assess their clinical significance.MethodsRelative quantification of IAPs and their antagonist genes was assessed by quantitative Real Time RT-PCR (qPCR) in 80 patients who underwent surgical resection for HCC. The expression ratios of XIAP/XAF1 and of XIAP/Smac were also evaluated. Survivin, XIAP and XAF1 protein expression were investigated by immunohistochemistry. Correlations between mRNA levels, protein expression and clinicopathological features were assessed. Follow-up data were available for 69 HCC patients. The overall survival analysis was estimated according to the Kaplan-Meier method.ResultsSurvivin and Livin/ML-IAP mRNAs were significantly over-expressed in cancer tissues compared to non-neoplastic counterparts. Although Survivin immunoreactivity did not correlate with qPCR data, a significant relation was found between higher Survivin mRNA level and tumor stage, tumor grade and vascular invasion.The mRNA ratio XIAP/XAF1 was significantly higher in HCCs than in cirrhotic tissues. Moreover, high XIAP/XAF1 ratio was an indicator of poor prognosis when overall survival was estimated and elevated XIAP immunoreactivity was significantly associated with shorter survival.ConclusionOur study demonstrates that alterations in the expression of IAP family members, including Survivin and Livin/ML-IAP, are frequent in HCCs. Of interest, we could determine that an imbalance in XIAP/XAF1 mRNA expression levels correlated to overall patient survival, and that high XIAP immunoreactivity was a poor prognostic factor.

Association between Low-Activity Serotonin Transporter Genotype and Heroin Dependence: Behavioral and Personality Correlates

In previous studies, serotonin (5‐HT) system disturbance was found involved in a variety of behavioral disorders, psychopathologies, and substance use disorders. A functional polymorphism in the promoter region of the human serotonin transporter gene (5‐HTTLPR) was recently identified and the presence of the short (S) allele found to be associated with a lower level of expression of the gene, lower levels of 5‐HT uptake, type 2 alcoholism, violence and suicidal behavior. In the present study, 101 heroin addicts (males, West European, Caucasians) and 101 healthy control subjects matched for race and gender, with no history of substance use disorder, have been genotyped. Aggressiveness levels were measured in both heroin addicts and controls utilizing Buss‐Durkee‐Hostility‐Inventory (BDHI). Data about suicide attempt and violent criminal behavior in subject history have been collected. The short–short (SS) genotype frequency was significantly higher among heroin dependent individuals compared with control subjects (P = 0.025). The odds ratio for the SS genotype versus the long–long (LL) genotype frequency was 0.69, 95% Cl (0.49–0.97), when heroin addicts were compared with healthy controls. The SS genotype frequency was significantly higher among violent heroin dependent individuals compared with addicted individuals without aggressive behavior (P = 0.02). BDHI mean total scores and suspiciousness and negativism subscales scores were significantly higher in SS individuals, in comparison with LL subjects, among heroin addicts. No association was found between SS genotype and suicide history. Our data suggest that a decreased expression of the gene encoding the 5‐HTT transporter, due to “S” promoter polymorphism, may be associated with an increased risk for substance use disorders, particularly in the subjects with more consistent aggressiveness and impulsiveness.

Proliferation of Transformed Somatotroph Cells Related to Low or Absent Expression of Protein Kinase A Regulatory Subunit 1A Protein

The two regulatory subunits (R1 and R2) of protein kinase A (PKA) are differentially expressed in cancer cell lines and exert diverse roles in growth control. Recently, mutations of the PKA regulatory subunit 1A gene (PRKAR1A) have been identified in patients with Carney complex. The aim of this study was to evaluate the expression of the PKA regulatory subunits R1A, R2A, and R2B in a series of 30 pituitary adenomas and the effects of subunit activation on cell proliferation. In these tumors, neither mutation of PRKAR1A nor loss of heterozygosity was identified. By real-time PCR, mRNA of the three subunits was detected in all of the tumors, R1A being the most represented in the majority of samples. By contrast, immunohistochemistry documented low or absent R1A levels in all tumors, whereas R2A and R2B were highly expressed, thus resulting in an unbalanced R1/R2 ratio. The low levels of R1A were, at least in part, due to proteasome-mediated degradation. The effect of the R1/R2 ratio on proliferation was assessed in GH3 cells, which showed a similar unbalanced pattern of R subunits expression, and in growth hormone-secreting adenomas. The R2-selective cAMP analog 8-Cl cAMP and R1A RNA silencing, stimulated cell proliferation and increased Cyclin D1 expression, respectively, in human and rat adenomatous somatotrophs. These data show that a low R1/R2 ratio promoted proliferation of transformed somatotrophs and are consistent with the Carney complex model in which R1A inactivating mutations further unbalance this ratio in favor of R2 subunits. These results suggest that low expression of R1A protein may favor cAMP-dependent proliferation of transformed somatotrophs.

Quantitative PCR and HER2 Testing in Breast Cancer : A Technical and Cost-Effectiveness Analysis

We performed a technical and cost-effectiveness analysis of quantitative reverse transcription-polymerase chain reaction (Q-RT-PCR) for the assessment of HER2 in breast cancer. We evaluated 44 frozen and 55 formalin-fixed paraffin-embedded (FFPE) breast carcinoma specimens by Q-RT-PCR, immunohistochemical analysis, and fluorescent in situ hybridization (FISH). Immunohistochemical and FISH analyses were performed on individual slides and on tissue microarray. Costs of techniques were calculated to study 1 case and 10 or 40 cases. Q-RT-PCR provided reliable data in frozen and FFPE specimens, which were significantly correlated. HER2 messenger RNA levels were significantly stratified in agreement with immunohistochemical data (P < .05). There was complete concordance between Q-RT-PCR and immunohistochemical results for negative and strongly positive (3+) cases. The intermediate immunohistochemical group (2+), including FISH+ and FISH- cancers, could also be stratified by Q-RT-PCR. Cost analysis documented the advantage of Q-RT-PCR in all US Food and Drug Administration-approved assays. Our data support the use of Q-RT-PCR for testing breast cancer specimens to select patients for HER2 inhibitory therapy.

Molecular and immunohistochemical analysis of HER2/neu oncogene in synovial sarcoma

Amplification and/or overexpression of HER2/neu have been documented in many types of epithelial tumor and recently has been reported in sarcomas, particularly in osteosarcomas. But the role of HER2/neu alterations in soft tissue tumors remains poorly understood. Thus the present study investigates the expression of HER2/neu in 13 patients with synovial sarcoma (SS). In this study, HER2/neu mRNA levels were measured in frozen tissue samples using a real-time reverse transcription-polymerase chain reaction assay; protein expression was assessed by immunohistochemistry using an anti-HER2/neu polyclonal antibody. Six normal skeletal muscle specimens were used to establish basal levels of HER2/neu mRNA. HER2/neu transcripts were detected in all normal tissues and SSs. Four of 13 sarcomas (31%) demonstrated HER2/neu mRNA levels above the mean value, whereas 3 tumors (23%) displayed HER2/neu protein overexpression. Both membranous and cytoplasmic patterns of immunostaining were observed, and a strong correlation was found between protein expression and mRNA level (P = 0.01). Increased HER2/neu mRNA levels were significantly associated with a lower risk of developing recurrences (P = 0.02). Moreover, none of the patients with HER2/neu overexpression developed metastasis. Our data demonstrate that HER2/neu is expressed in SSs and that both membrane and cytoplasmic HER2/neu expression correlate with mRNA levels. Our results show that the presence of increased levels of HER2/neu in SSs is associated with a more favorable clinical course. Further studies are needed to assess the role of this oncogene in SSs and to evaluate the application of inhibitory humanized monoclonal antibodies in the treatment regimens for this malignancy.

p21WAF1/CIP1 expression in colorectal carcinoma correlates with advanced disease stage and p53 mutations.

Defects in the mechanisms controlling the cell cycle are crucial in cell transformation and/or tumour progression. p21WAF1/CIP1 is an inhibitor of cyclin‐dependent kinases, induced by p53‐dependent and p53‐independent pathways, which can block progression through the cell cycle. p21WAF1/CIP1 expression has been investigated immunohistochemically in a series of 191 patients with colorectal cancer of known p53 status. The purpose of the study was two‐fold: to assess the relationship between p21WAF1/CIP1 immunoreactivity and p53 alterations, and to evaluate the prognostic significance of p21WAF1/CIP1 expression. In 96 carcinomas (51 per cent), p21WAF1/CIP1 was expressed in over 10 per cent of tumour cells, whereas in 26, p21WAF1/CIP1 was detected in under 10 per cent of neoplastic cells; 69 tumours lacked p21WAF1/CIP1 expression. Immunoreactivity was more frequent in tumours of the right colon (p < 0·003) and was inversely correlated with tumour stage (p < 0·03), p53 gene mutations (p < 0·0007), p53 protein accumulation (p < 0·019), and Bcl‐2 expression (p < 0·0005). In univariate analysis, down‐regulation of p21WAF1/CIP1 expression was associated with poor overall (p = 0·0022) and disease‐free survival (p = 0·0009). Multivariate analysis, however, did not confirm any independent prognostic significance of p21WAF1/CIP1 expression. The results indicate that p21WAF1/CIP1 is associated with abnormal accumulation of p53 protein and the occurrence of p53 gene mutations in colorectal cancer and that lack of p21WAF1/CIP1 expression is correlated with reduced patient survival in univariate analysis. These data underline the crucial pathogenetic role of the p53–p21WAF1/CIP1 pathway in carcinomas of the large bowel. Copyright

Prediction of survival in stage I lung carcinoma patients by telomerase function evaluation.

Telomerase activity and telomerase reverse transcriptase (hTERT) expression are elevated in human malignancies. We have investigated telomerase activity measured by the telomeric repeat amplification protocol (TRAP) assay and hTERT levels by real-time RT-PCR in stage I non-small-cell lung carcinomas. The purposes of our study included the comparison of these two techniques in the assessment of telomerase function and the evaluation of their prognostic significance. Telomerase activity and hTERT levels were determined in 90 stage I non-small-cell lung carcinoma patients, using TRAP assay and real-time RT-PCR, respectively. Variables were analyzed by the χ2 and Fisher exact tests. Survival was analyzed by the Kaplan-Meier method. Multivariate analysis was performed with the Coxs proportional hazards model. Telomerase activity was elevated in 60 (67%) carcinomas. hTERT was elevated in 43 (48%) carcinomas. Only 21 (23%) tumors had low telomerase function by both TRAP and hTERT expression levels. Telomerase activity and hTERT were significantly correlated (p = 0.017), although 35 cases displayed discordant results. Both telomerase activity and hTERT levels were significantly associated with poor patient overall and disease-free survival (p = 0.019 and p = 0.018 for TRAP, and p = 0.011 and p = 0.012 for hTERT, respectively). Among the 21 patients with tumors displaying low telomerase function, defined by both TRAP and hTERT expression levels, only one succumbed to the disease (p = 0.0053). Our results suggest that the two techniques used in this study evaluate separate aspects of telomerase function and their combination provides powerful prognostic information in lung cancer patients.

Gene expression analysis of early and advanced gastric cancers

Gastric carcinoma is one of the major causes of cancer mortality worldwide. Early detection results in excellent prognosis for patients with early cancer (EGC), whereas the prognosis of advanced cancer (AGC) patients remains poor. It is not clear whether EGC and AGC are molecularly distinct, and whether they represent progressive stages of the same tumor or different entities ab initio. Gene expression profiles of EGC and AGC were determined by Affymetrix technology and quantitative polymerase chain reaction. Representative regulated genes were further analysed by in situ hybridization (ISH) on tissue microarrays. Expression analysis allowed the identification of a signature that differentiates AGC from EGC. In addition, comparison with normal gastric mucosa indicated that the majority of alterations associated with EGC are retained in AGC, and that further expression changes mark the transition from EGC to AGC. Finally, ISH analysis showed that representative genes, differentially expressed in the invasive areas of EGC and AGC, are not differentially expressed in the non-invasive areas of the same tumors. Our data are more directly compatible with a progression model of gastric carcinogenesis, whereby EGC and AGC may represent different molecular stages of the same tumor. Finally, the identification of an AGC-specific signature might help devising novel therapeutic strategies for advanced gastric cancer.

Allelic association of a dopamine transporter gene polymorphism with antisocial behaviour in heroin-dependent patients

Polymorphism of a variable number of tandem repeats (VNTR) in the 3′ untranslated region of exon 15 of the SLC6A3 gene, coding for the dopamine transporter (DAT), was analysed to test whether length variation contributes to differences in the individual susceptibility to aggressive – criminal behaviour and liability to heroin dependence. The repeat number of the DAT polymorphism was assessed in 125 healthy subjects and 104 heroin‐dependent subjects (including 52 addicted individuals with violent behaviour and criminal records). There was no significant difference in the frequencies of genotypes and alleles between heroin‐dependent subjects and control subjects. On the contrary, there was a significant difference between offenders and non‐offenders, p  = 0.004 and p  = 0.002, respectively, among heroin‐dependent subjects. No association was found between DAT polymorphism and history of suicide. Buss – Durkee Hostility Inventory (BDHI) mean total scores were significantly higher in heroin addicts than in controls (p  < 0.001) and in antisocial – violent heroin addicts in comparison with addicted individuals without antisocial behaviour (p  < 0.005). The regression analysis of BDHI subscales, performed to provide an estimate of the magnitude of any potential effect on the risk of aggressiveness associated with the variants in DAT VNTR, showed that the presence of the 9 – 9 genotype significantly increases the risk of irritability and direct aggressiveness more than six and 10 times with respect to the 9 – 10 genotype. Our findings suggest that the 9‐repeat allele of the DAT polymorphism confers increased susceptibility to antisocial – violent behaviour and aggressiveness, rather than drug dependence per se in heroin‐dependent males.

HER2 in gastric cancer: a digital image analysis in pre-neoplastic, primary and metastatic lesions

The assessment of human epidermal growth factor receptor 2 (HER2) status in gastric cancer is crucial in selecting patients who may benefit from targeted therapy, yet heterogeneous expression could represent an important drawback for HER2 testing. We aimed to analyze (i) HER2 heterogeneity in primary gastric cancers, pre-neoplastic and metastatic lesions and (ii) HER2 prognostic role. We studied 292 surgically resected primary gastric carcinomas and constructed 21 tissue microarrays including tumor tissue cores, invasive front, paired lymph node metastasis, low- and high-grade dysplasia. Microarrays were immunohistochemically stained with HER2 antibody and digitally scanned. Novel digital analysis algorithms were developed to score HER2 expression. Fluorescence in situ hybridization was performed on equivocal cases. HER2-positive cases were 13% and heterogeneous HER2 expression was observed in 71% of positive samples. Analysis of HER2 status in tumor and tumor invasive front demonstrate concordance in 177 cases (88%). Comparison of HER2 expression in primary cancer and synchronous lymph node metastasis exhibited discordant status in 14% of cases. Dysplastic epithelium surrounding the tumor showed immunohistochemical score 2 or 3 in 19% of high-grade and in 9% of low-grade dysplastic samples. HER2 status was significantly associated with intestinal-type carcinomas (P=0.018) and prognosis since patients with primary HER2-positive tumor showed decreased overall survival (P=0.006). Intratumoral HER2 expression heterogeneity and variable lymph node metastases status strongly suggest evaluating more than one sample and, if available, metastatic foci for routinely HER2 testing.