The AKT2 gene is one of the human homologues of v-akt, the transduced oncogene of the AKT8 virus, which induces lymphomas in mice. In previous studies, AKT2, which codes for a serine-threonine protein kinase, was shown to be amplified and overexpressed in some human ovarian carcinoma cell lines and amplified in primary tumors of the ovary. To confirm and extend these findings, we conducted a large-scale, multicenter study of AKT2 alterations in ovarian and breast cancer. Southern-blot analysis demonstrated AKT2 amplification in 16 of 132 (12.1%) ovarian carcinomas and in 3 of 106 (2.8%) breast carcinomas. No AKT2 alteration was detected in 24 benign or borderline tumors. Northern-blot analysis revealed overexpression of AKT2 in 3 of 25 fresh ovarian carcinomas which were negative for AKT2 amplification. The difference in the incidence of AKT2 alterations in ovarian and breast cancer suggests a specific role for this gene in ovarian oncogenesis. No significant association was found between AKT2 amplification and amplification of the proto-oncogenes MYC and ERBB2, suggesting that amplification of AKT2 defines an independent subset of breast and ovarian cancers. Ovarian cancer patients with AKT2 alterations appear to have a poor prognosis. Amplification of AKT2 was especially frequent in undifferentiated tumors (4 of 8, p = 0.019), suggesting that AKT2 alterations may be associated with tumor aggressiveness.

In an effort to identify tumor suppressor gene(s) associated with the frequent loss of heterozygosity observed on chromosome 6q25–q27, we constructed a contig derived from the sequences of bacterial artificial chromosome/P1 bacteriophage artificial chromosome clones defined by the genetic interval D6S1581–D6S1579–D6S305–D6S1599–D6S1008. Sequence analysis of this contig found it to contain eight known genes, including the complete genomic structure of the Parkin gene. Loss of heterozygosity (LOH) analysis of 40 malignant breast and ovarian tumors identified a common minimal region of loss, including the markers D6S305 (50%) and D6S1599 (32%). Both loci exhibited the highest frequencies of LOH in this study and are each located within the Parkin genomic structure. Whereas mutation analysis revealed no missense substitutions, expression of the Parkin gene appeared to be down-regulated or absent in the tumor biopsies and tumor cell lines examined. In addition, the identification of two truncating deletions in 3 of 20 ovarian tumor samples, as well as homozygous deletion of exon 2 in the lung adenocarcinoma cell lines Calu-3 and H-1573, supports the hypothesis that hemizygous or homozygous deletions are responsible for the abnormal expression of Parkin in these samples. These data suggest that the LOH observed at chromosome 6q25–q26 may contribute to the initiation and/or progression of cancer by inactivating or reducing the expression of the Parkin gene. Because Parkin maps to FRA6E , one of the most active common fragile sites in the human genome, it represents another example of a large tumor suppressor gene, like FHIT and WWOX , located at a common fragile site.

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Serum levels of IL-6 were evaluated in a large group of patients with benign or malignant gynecological tumors. The results obtained were correlated with the patients' clinicopathological features and follow-up data. Using a highly sensitive immunoenzymatic method for the evaluation of serum IL-6 levels, we observed that > 95% of normal healthy women exhibited values within the range of 1.9-6 pg/ml. Using a cut-off of 6 pg/ml, elevated levels of serum IL-6 were found in 53% of 45 patients with primary epithelial ovarian cancer and less frequently in patients with endometrial and cervical cancer (37% and 10% respectively). Elevated levels of IL-6 were occasionally seen in patients with benign disease. IL-6 serum levels appeared to be less sensitive than CA 125 in ovarian cancer diagnosis. In cancer patients, increased IL-6 serum levels were related to the presence of the tumor since all post-operative patients exhibited a marked decrease. In patients with advanced ovarian cancer post-operative levels of IL-6 correlated with residual disease. Very high levels of IL-6 were observed in the ascitic fluid of 9 ovarian cancer patients, but IL-6 mRNA was not detected in tumor cells. This suggests that the increased production of IL-6 observed in ovarian cancer is reactive. Higher levels of IL-6 were found in patients unresponsive to chemotherapy, as compared with responsive ones. Univariate analysis of survival data suggests that increased IL-6 serum levels correlate with negative prognosis.