Shalina Gupta-Burt

PURPOSE: The putative association between erbB-2 overexpression and favorable response to anthracyline-based therapy in breast cancer is controversial, and the mechanism unclear. We sought to determine whether coamplification and overexpression of the topoisomerase IIalpha gene, near erbB-2 on chromosome 17, and a known anthracycline target, may underlie the association. EXPERIMENTAL DESIGN: Thirty-five patients who had locally advanced breast cancer (LABC) and who had received neoadjuvant, anthracycline-based therapy were studied. Copy number of topoisomerase IIalpha and erbB-2 was determined by fluorescence in situ hybridization, and expression by immunohistochemistry. RESULTS: Of 8 patients with erbB-2 amplification, 5 had a complete response (CR) or minimal residual disease (MRD), 3 had a partial response (PR), and none had stable (StD) or progressive disease (PD) at the time of mastectomy, versus 3 CR or MRD, 16 PR, and 8 StD or PD for patients without amplification (P = 0.008). In contrast, erbB-2 overexpression was not significantly associated with response (P = 0.114). Of 6 patients with topoisomerase IIalpha amplification, 4 had CR or MRD, 2 PR, and none StD or PD, versus 4 CR or MRD, 17 PR, and 8 StD or PD for patients without amplification (P = 0.034). All of the tumors with topoisomerase IIalpha amplification also had erbB-2 amplification, but not vice versa. Overexpression of topoisomerase IIalpha (9 patients) was also associated with favorable response (P = 0.021). CONCLUSIONS: Coamplification of erbB-2 and topoisomerase IIalpha is significantly associated with favorable local response to anthracycline-based therapy in LABC. The expression data favor a plausible mechanism based on topoisomerase IIalpha biology.

The persistence of platinum-DNA adducts was investigated using normal rats as well as tissues from cancer patients receiving either cisdiamminedichloroplatinum(II) (cisplatin) or diamminecyclobutanedicarboxylatoplatinum(II) (carboplatin) for cancer chemotherapy. These studies used an enzyme-linked immunosorbent assay, established with a rabbit anti-cisplatin-DNA that is specific for intrastrand platinum-DNA adducts. The gonads and kidneys of male and female rats, sites for antitumor activity and toxicity, respectively, were monitored for cisplatin-DNA adduct formation after a single dose of drug and during multiple-dose exposures (once a wk for 3 wk). DNA adducts were measured by enzyme-linked immunosorbent assay 4 h and 2, 4, 7, and 14 days after administering a single i.v. injection of 8 mg/kg of cisplatin. Adduct profiles in renal tissues were similar in both males and females with adduct levels increasing between 4 h and 2 days, decreasing between Days 2 and 7, and stable between Days 7 and 14. In both sexes, levels of kidney DNA adduct measured 7 to 14 days after cisplatin injection comprised about 30% of the highest (Day 2) value. In testes and ovaries, adduct removal was complete by 4 days, and 40 to 50% of adducts present at Day 2 persisted until Days 7 and 14. A study of multiple dosing showed that adducts in renal and testicular DNA from rats given three weekly doses of 5 mg/kg of cisplatin had different accumulation profiles. In the testis there was a 2-fold accumulation of adduct after the third dose, while in the kidney adducts dropped with repeated dosing. In humans, the persistence of platinum-DNA adducts was studied in tissues from eight cancer patients who received their last dose of cisplatin or carboplatin chemotherapy between 1 day and 15 mo before autopsy. The patients had either ovarian cancer, breast cancer, or lymphoma, and the tissues studied included ovarian tumor, bone marrow, kidney, liver, spleen, lymph node, peripheral nerve, and brain. When samples were available from tumor tissues and from bone marrow within the same patient, adduct levels were similar in the two tissues. In addition, adducts were persistent for many months, since half of the individuals received their most recent platinum-drug therapy 7 to 15 mo before death. Overall, these studies demonstrate a widespread distribution and high degree of platinum-DNA adduct persistence in both animal and human tissues subsequent to cisplatin or carboplatin treatment.

This study will evaluate the safety and efficacy of allogenic donor lymphocyte infusions in patients who have relapsed hematologic malignancies after allogeneic bone marrow transplantation (BMT). Donor lymphocyte transfusions have resulted in the cure of some patients with relapsed leukemia or lymphoproliferative disorder after allogeneic BMT, but has been complicated by the development of graft versus host disease (GvHD). We hypothesize that a retroviral vector containing the Herpes simplex thymidine kinase (HStk) gene will allow for retention of the anti-leukemia response of transfused donor lymphocytes while allowing for the adverse effects of GVHD to be mitigated. Patients with relapsed hematologic malignancies after allogeneic BMT will be infused with ex vivo gene modified donor lymphocytes. The Herpes Simplex thymidine kinase (HStk) gene will be transduced into the cells ex vivo using LTKOSN. 1 vector supernate. Insertion of the HStk gene into lymphocytes confers a sensitivity to the anti-herpes drug ganciclovir (GCV). This selective destruction of donor lymphocytes in situ will be used to abrogate the effect of graft versus host disease, if it develops.

Nucleated blood cell DNA samples from ovarian (n = 27) and breast (n = 25) cancer patients receiving either cis-diamminedichloroplatinum II (cisplatin) and/or diamminecyclobutanecarboxylatoplatinum II were examined for the presence of platinum drug bound to DNA during several cycles of therapy. Platinum-DNA adducts were quantitated by cisplatin-DNA enzyme-linked immunosorbent assay (ELISA) and atomic absorbance spectroscopy, techniques that measure either a fraction of the intrastrand cis-diammineplatinum-d(ApG) and -d(GpG) adducts (ELISA) or the total platinum bound to DNA (atomic absorbance spectroscopy), respectively. For either the complete study, or for samples obtained during the early cycles, individuals with progressive disease had severalfold lower overall cisplatin-DNA ELISA-measurable adduct levels than the individuals with more favorable clinical responses (complete response, partial response, or stable disease), who were grouped together and termed nonprogressive disease. In the case of the ovarian cancer patients, who experienced a 59% rate of complete and partial response, the correlation of high adduct values with disease response was statistically significant by the Wilcoxon rank-sum test (P = 0.028). In contrast, the breast cancer patients achieved only an 11.5% rate of complete and partial response, and the correlation of high adduct formation with disease response was not statistically significant. Levels of total DNA-bound platinum, measured by atomic absorbance spectroscopy, showed no correlation with disease response for either cancer by any analysis. The study supports previous observations demonstrating a consistent correlation between high cisplatin-DNA ELISA measurements and positive clinical outcome in ovarian cancer patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies of platinum drug-DNA adduct formation in tissues of cancer patients have involved both atomic absorbance spectroscopy (AAS), which measures total DNA-bound platinum, and anti-cisplatin-DNA enzyme-linked immunosorbent assay (ELISA), which detects a fraction of the AAS-measurable adduct. These studies were designed to explore mechanisms of drug-DNA interactions, to make correlations with clinical outcome, and possibly to validate DNA adduct measurements for use in occupational and environmental biomonitoring. The results, determined by both ELISA and AAS, demonstrate that cisplatin and its analog carboplatin bind to DNA in many human organs, including kidney, brain, peripheral nerve, and bone marrow, which are sites for drug toxicity. Platinum was also observed bound to ovarian tumor DNA. The adducts were highly persistent, being measurable in tissues obtained at autopsy up to 15 months after the last administration of platinum chemotherapy. A comparison of blood cell DNA adduct levels, determined by ELISA, and the clinical response of 139 patients with ovarian, testicular, colon, or breast cancer demonstrated a strong correlation between failure to form DNA adducts and failure of therapy. Conversely, patients who formed high levels of DNA adduct were most likely to respond favorably. A similar correlation was not observed for adducts determined by AAS; that is, the average total DNA-bound platinum levels were the same for patients who did not respond to therapy and for patients who had any kind of response. Thus, in this study, human blood cell DNA adducts measured by ELISA correlate with tumor remission, while those measured by AAS do not.