Genetic variations at loci involved in the immune response are risk factors for hepatocellular carcinoma

Primary liver cancer is the third most common cause of cancer-related death worldwide, with a rising incidence in Western countries. Little is known about the genetic etiology of this disease. To identify genetic factors associated with hepatocellular carcinoma (HCC) and liver cirrhosis (LC), we conducted a comprehensive, genome-wide variation analysis in a population of unrelated Asian individuals. Copy number variation (CNV) and single nucleotide polymorphisms (SNPs) were assayed in peripheral blood with the high-density Affymetrix SNP6.0 microarray platform. We used a two-stage discovery and replication design to control for overfitting and to validate observed results. We identified a strong association with CNV at the T-cell receptor gamma and alpha loci (P < 1 × 10(-15)) in HCC cases when contrasted with controls. This variation appears to be somatic in origin, reflecting differences between T-cell receptor processing in lymphocytes from individuals with liver disease and healthy individuals that is not attributable to chronic hepatitis virus infection. Analysis of constitutional variation identified three susceptibility loci including the class II MHC complex, whose protein products present antigen to T-cell receptors and mediate immune surveillance. Statistical analysis of biologic networks identified variation in the "antigen presentation and processing" pathway as being highly significantly associated with HCC (P = 1 × 10(-11)). SNP analysis identified two variants whose allele frequencies differ significantly between HCC and LC. One of these (P = 1.74 × 10(-12)) lies in the PTEN homolog TPTE2. Conclusion: Combined analysis of CNV, individual SNPs, and pathways suggest that HCC susceptibility is mediated by germline factors affecting the immune response and differences in T-cell receptor processing.     

Inhibition of tumorigenicity in lung adenocarcinoma cells by c-erbB-2 antisense expression

The lung carcinoma cell line Calu3, which overexpresses the c-erbB-2 oncogene, was stably transfected with antisense (AS) cDNA constructs encompassing different regions of the c-erbB-2 gene. Transfected cells were analyzed for their tumorigenic properties in vitro and in nude mice. Two independent clones, AS F1 (low erbB-2 expressor) and AS B12 (high erbB-2 expressor), as well as the polyclonal Calu3/AS 5′, were selected for these analyses. In Calu3/AS 5′ transfected cells and in the AS F1 clone, c-erbB-2 RNA and protein levels were lower than those detected in the parental cell line and the AS B12 clone. Anchorage-independent growth and tumor take were also significantly reduced. Furthermore, cells derived from primary tumors of Calu3/AS 5′, AS F1 and AS B12 lost the AS c-erbB-2 DNA insert but retained the gene for G418 resistance. Our results suggest that a correlation between c-erbB-2 overexpression and tumorigenicity may exist in the Calu3 lung carcinoma cell line. Int. J. Cancer 72:631–636, 1997. © 1997 Wiley-Liss, Inc.     

Knowledge of HIV/AIDS and emotional adjustment in a cohort of men with haemophilia and HIV infection: final report

This study presents the final report of a long-term psychological assessment of men with haemophilia and HIV infection. The knowledge, emotional impact regarding HIV infection and prospective changes over time and the need for psychological support were evaluated. The study group comprised 118 men with haemophilia, 66 HIV seropositive and 52 seronegative, from the Haemophilia Centres in Bari, Florence, Milan and Naples. All subjects performed psychological tests (STAI: state and trait anxiety inventory; SDS: self-rating depression scale) and completed questionnaires to ascertain their knowledge and the emotional impact of AIDS. After enrollment (1992-93) the assessment was repeated twice over a 2-year period. A high percentage of subjects in both groups answered the questionnaire on knowledge correctly and, more specifically, all (100%) admitted knowing that sexual intercourse was a risk factor for HIV infection, adding that sexual partners of haemophiliacs with HIV should be regularly tested. The percentage, however, decreased for seropositives who admitted to always using a condom during sexual intercourse (86%) and for those who declared that partners were periodically tested for HIV (60%). The most important feature of the study is that, contrary to predicted expectations, seropositive and seronegative subjects presented the same degree of emotional involvement: there are no statistically significant differences in average scores between groups either on the anxiety or depression scales. Moreover, for certain aspects, seronegatives revealed greater emotional involvement: at baseline evaluation, they felt more fear and unhappiness with statistically significant differences compared to asymptomatics. Furthermore, seronegatives more than seropositives continue to feel reluctance towards infusion and avoid blood products after learning of AIDS. These results emphasize the importance of paying due attention to the emotional status of seronegatives. Their reluctance towards the use of blood products (despite present safety) is a very important issue for the possible consequences of treatment with the risk of worsening the clinical condition. In conclusion, we believe that counselling on HIV infection/AIDS needs to address every person with haemophilia regardless of HIV status.     

Basic mutant Max reverses a c-Myc block to differentiation

Murine erythroleukemia (MEL) cells overexpressing a transfected c-myc gene are blocked in their ability to undergo inducer-mediated differentiation, whereas overexpression of a transfected max gene mutated within the basic region (bm-max) accelerates differentiation. Based on these findings, we cotransfected MEL cells with plasmids which express human c-Myc constitutively and bm-Max in a zinc-inducible manner. Competition of endogenous proteins for binding to bm-Max can be considered negligible in cells expressing such high constitutive levels of c-Myc. Thus, this system provides a cell culture model for studying Myc:Max complex formation and its effect on erythroid differentiation. Clones expressing high levels of c-Myc and low levels of bm-Max are blocked in their ability to undergo N,N'-hexamethylene bisacetamide (HMBA)-mediated differentiation, presumably due to a preponderance of growth-promoting Myc:Max complexes. However, increased expression of bm-Max, in these clones, allows differentiation to occur by decreasing the levels of functional Myc:Max complexes. Although the exogenously expressed c-Myc and bm-Max associate in vivo, the basic region mutation in bm-Max abolishes the binding of Myc:bm-Max complexes to the specific E-box consensus sequence. We demonstrate that this sequestering of c-Myc by bm-Max reverses the c-Myc block to differentiation.