Wilberto Nieves-Neira

Apoptotic response to camptothecin and 7‐hydroxystaurosporine (UCN‐01) in the 8 human breast cancer cell lines of the NCI anticancer drug screen: Multifactorial relationships with topoisomerase i, protein kinase C, Bcl‐2, p53, MDM‐2 and caspase pathways

Derivatives of camptothecins, topoisomerase I inhibitors and 7‐hydroxystaurosporine (UCN‐01), a protein kinase C (PKC) inhibitor and cell cycle checkpoint abrogator, are promising anticancer drugs. We characterized the apoptotic response to camptothecin and UCN‐01 for the 8 human breast carcinoma cell lines (MCF‐7, MCF‐7/ADR, T47D, HS578T, BT549, MDA‐N, MDA MB231, MDA435) from the National Cancer Institute (NCI) Anticancer Drug Screen. MCF‐7 and T47D cells exhibited marked resistance to apoptosis, whereas MCF‐7/ADR (NCI/ADR‐RES) and HS578T cells exhibited the most pronounced apoptotic response. Apoptotic response was not correlated with growth inhibition measured by sulforhodamine B (SRB) assay, indicating that apoptosis is not the only mechanism of drug‐induced cell death. Measurements of topoisomerase I levels and cleavage complexes and of PKC isoforms demonstrated that primary target inhibition was not correlated with apoptotic response. Several key apoptotic pathways were evaluated. Only MCF‐7 cells had wild‐type p53, indicating that p53 is not required for drug‐induced apoptosis. MCF‐7 cells also showed the highest MDM‐2 expression (along with T47D cells, which were also resistant to apoptosis). Bcl‐2, Mcl‐1 and caspases 2 and 3 protein levels varied widely, whereas Bax expression was comparable among cell lines. Interestingly, Bcl‐2, Mcl‐1 and Bcl‐XL cumulative expressions were inversely correlated with apoptotic response. Our results provide a comparative molecular characterization for the breast cancer cell lines of the NCI Anticancer Drug Screen and demonstrate the diversity of cellular responses to drugs (apoptosis vs. cell cycle arrest) and the importance of multifactorial analyses for modulating/predicting the apoptotic response to chemotherapy. Int. J. Cancer 82:396–404, 1999. Published 1999 Wiley‐Liss, Inc.

Role of oxygen radicals generated by NADPH oxidase in apoptosis induced in human leukemia cells.

We have used a human leukemia cell line that, after homologous recombination knockout of the gp91-phox subunit of the phagocyte respiratory-burst oxidase cytochrome b-558, mimics chronic granulomatous disease (X-CGD) to study the role of oxygen radicals in apoptosis. Camptothecin (CPT), a topoisomerase I inhibitor, induced significantly more apoptosis in PLB-985 cells than in X-CGD cells. Sensitivity to CPT was enhanced after neutrophilic differentiation, but was lost after monocytic differentiation. No difference between the two cell lines was observed after treatment with other apoptosis inducers, including etoposide, ultraviolet radiation, ionizing radiation, hydrogen peroxide, or 7-hydroxystaurosporine. After granulocytic differentiation of both cell lines, CPT still induced apoptosis, suggesting independence from replication in fully differentiated and growth-arrested cells. Pyrrolidine dithiocarbamate (an antioxidant inhibitor of NF-kappaB) and catalase partially inhibited CPT-induced DNA fragmentation in granulocytic-differentiated PLB-985 cells, but had no effect in X-CGD cells. Flow cytometry analysis revealed that reactive oxygen intermediates were generated in CPT-treated PLB-985 cells. These data indicate that oxygen radicals generated by NADPH oxidase may contribute directly or indirectly to CPT-induced apoptosis in human leukemia and in neutrophilic-differentiated cells.

Activation of the Fas pathway independently of Fas ligand during apoptosis induced by camptothecin in p53 mutant human colon carcinoma cells

The present study explored the role of the cell surface receptor Fas (CD95/APO-1) in apoptosis induced by camptothecin (CPT) in the HT29 colon carcinoma cell line. CPT-induced apoptosis was associated with high molecular weight DNA fragmentation as measured by filter elution. This fragmentation was inhibited by the caspase inhibitor, z-VAD-fmk and by cycloheximide, which also prevented proteolytic activation of caspase-3 and poly(ADP-ribose)polymerase cleavage. Under such conditions, Fas, Fas ligand, Bax, and p21 expression were increased and Fas recruited the FADD adaptor. Fas expression increase was blocked by cycloheximide but not by z-VAD-fmk, consistent with caspase activation downstream from Fas. Treatment of HT29 cells with FasL or with the CH-11 agonistic anti-Fas antibody potentiated the apoptotic response of cells treated with CPT. The anti-Fas blocking antibody ZB4 and the Fas-ligand inhibitor failed to protect HT29 cells from CPT-induced apoptosis. Such a protection was obtained by transient expression of constructs encoding a dominant-negative mutant of FADD, FADD in an antisense orientation and E8 or MC159 viral proteins that inhibit Fas-induced apoptosis at the level of FADD and procaspase-8, respectively. Together, these data show that topoisomerase I-mediated DNA damage-induced apoptosis involves activation of the Fas pathway without detectable Fas-ligand requirement in CPT-treated cells.

Receipt of vaginal brachytherapy is associated with improved survival in women with stage I endometrioid adenocarcinoma of the uterus: A National Cancer Data Base study.

Randomized controlled trials have consistently shown that the use of postoperative radiotherapy (RT) for stage I endometrial cancer leads to a reduction in the incidence of pelvic recurrences without a corresponding reduction in overall mortality. It was hypothesized that a reduction in mortality associated with the receipt of RT could be identified in a large data set with greater statistical power.

Chemotherapy delay after primary debulking surgery for ovarian cancer

OBJECTIVE To determine the association of chemotherapy delay with overall survival (OS) and investigate predictors of delay among a population-representative American ovarian cancer cohort. METHODS An observational retrospective cohort analysis of women with ovarian cancer who received National Comprehensive Cancer Network guideline-consistent care was performed with the 1998-2011 National Cancer Data Base. Chemotherapy delay was defined as initiation of multiagent chemotherapy >28days from primary debulking surgery. Associations of patient and disease characteristics with chemotherapy delay were tested with multivariate logistic regression. Survival analyses for women diagnosed from 2003 to 2006 approximated a 21-daycycle intravenous platinum-taxane chemotherapy cohort. Overall survival was estimated by Kaplan-Meier analyses and Cox proportional-hazards regressions, with sensitivity analyses using matched cohorts. RESULTS 58.1% (26,149/45,001) of women experienced chemotherapy delay. Race, insurance status, cancer center type, and community median income were significantly associated with chemotherapy delay (P<0.001). Odds for chemotherapy delay were higher for older or sicker women, women with endometrioid or mucinous histology, lower stage or grade disease, and uninsured or low-income women (P<0.05). Chemotherapy delay >35days from surgery was associated with a 7% (95% confidence interval, 2-13%) increased hazard of death (P=0.01). Relative hazard of death was lowest between 25 and 29days after surgery but was not significantly different within the longer two-week interval from 21 to 35days. CONCLUSION A survival benefit may be achieved by consistently starting chemotherapy between 21 and 35days from primary debulking surgery. Women at higher risk for chemotherapy delay may be targeted for close follow-up.

Survival after pelvic exenteration for uterine malignancy: A National Cancer Data Base study

OBJECTIVE To determine overall survival (OS) and factors associated with OS after pelvic exenteration for uterine cancer. METHODS Women with uterine cancer who underwent exenteration (n=1160) were identified from the 1998-2011 National Cancer Data Base. Kaplan-Meier and multivariate Cox proportional-hazards survival analyses were performed to test for associations of potential explanatory variables with OS. Analyzed confounders included age, comorbidity score, insurance status, income, distance from home to treatment center, stage, distant and nodal metastasis, tumor size, surgical margin status, exenteration type, and treatment with radiation and/or chemotherapy. RESULTS Among women with follow-up data (n=652), median (IQR) OS was 63.1 (42.2-107.2) and 17.6 (14.7-23.9) months for women with node-negative versus node-positive disease, respectively. Histology (p=1.5×10-4), grade (p=7.9×10-14), race (p=0.0002), lymph node status (p=1.0×10-14), surgical node evaluation (p=2.8×10-8), surgery for distant metastasis (p=0.004), distant metastasis at diagnosis (p=1.3×10-10), positive surgical margins (p=1.6×10-9), radiotherapy (p=0.004), and insurance status (p=6.5×10-6) were significantly associated with differential, unadjusted Kaplan-Meier OS estimates. Exenteration type was not associated with OS (p=0.357). By multivariate regression, increased age, positive surgical margins, nodal metastasis or unknown nodal status, higher histologic grade, and black race were associated with increased hazards for death. CONCLUSION Exenteration may be curative for well-selected women with uterine cancer, particularly among women with pathologically negative lymph nodes.

Phase 2 trial of paclitaxel, 13-cis retinoic acid, and interferon alfa-2b in the treatment of advanced stage or recurrent cervical cancer.

Objective Overexpression of bcl-2 is a mechanism of drug resistance in cervical cancer. Agents that down-regulate bcl-2 may decrease tumor cell threshold and sensitize tumor cells to chemotherapy. The objective of this multi-institutional phase 2 trial was to evaluate the efficacy and toxicity of paclitaxel and bcl-2 modulators (13-cis retinoic acid and interferon alfa-2b) in patients with advanced-stage or recurrent cervical cancer. Materials and Methods Patients had biopsy-proven metastatic, first relapse, or persistent cervical cancer with no prior chemotherapy except for chemosensitizing agents. The treatment consisted of oral 13-cis retinoic acid, 1 mg/kg, and subcutaneous interferon alfa-2b, 6 mU/m2, days 1 to 4, and intravenous paclitaxel, 175 mg/m2, day 4 until disease progression or adverse events prohibited treatment. The primary endpoint was overall response rate. Results Thirty-three patients were enrolled between March 2001 and June 2009. Thirty-one patients were eligible for evaluation of treatment response. Twenty-seven patients (82%) received prior concurrent chemoradiation or radiotherapy alone before study enrollment. The overall response rate was 30% (6 complete responses and 4 partial responses). Furthermore, 7 patients (21%) had stable disease. Grade 3 or 4 adverse events included neutropenia (n =16 [48%]), febrile neutropenia (n = 1 [3%]), and anemia (n = 1 [3%]). There were no treatment-related deaths. The median progression-free survival was 3.4 months (95% confidence interval, 2.0–7.4 months), and overall survival was 11.2 months (95% confidence interval, 7.5–26.2 months). Of 6 patients with complete responses, 5 patients survived more than 2 years. Conclusions Combination therapy with paclitaxel, 13-cis retinoic acid, and interferon alfa-2b is feasible and safe in treating patients with advanced and recurrent cervical cancer.

Cancer-testis antigen expression is shared between epithelial ovarian cancer tumors

OBJECTIVES Cancer-testis (CT) antigens have been proposed as potential targets for cancer immunotherapy. Our objective was to evaluate the expression of a panel of CT antigens in epithelial ovarian cancer (EOC) tumor specimens, and to determine if antigen sharing occurs between tumors. METHODS RNA was isolated from EOC tumor specimens, EOC cell lines and benign ovarian tissue specimens. Real time-PCR analysis was performed to determine the expression level of 20 CT antigens. RESULTS A total of 62 EOC specimens, 8 ovarian cancer cell lines and 3 benign ovarian tissues were evaluated for CT antigen expression. The majority of the specimens were: high grade (62%), serous (68%) and advanced stage (74%). 58 (95%) of the EOC tumors analyzed expressed at least one of the CT antigens evaluated. The mean number of CT antigen expressed was 4.5 (0-17). The most frequently expressed CT antigen was MAGE A4 (65%). Antigen sharing analysis showed the following: 9 tumors shared only one antigen with 62% of the evaluated specimens, while 37 tumors shared 4 or more antigens with 82%. 5 tumors expressed over 10 CT antigens, which were shared with 90% of the tumor panel. CONCLUSION CT antigens are expressed in 95% of EOC tumor specimens. However, not a single antigen was universally expressed across all samples. The degree of antigen sharing between tumors increased with the total number of antigens expressed. These data suggest a multi-epitope approach for development of immunotherapy for ovarian cancer treatment.

Survival after Pelvic Exenteration for Cervical Cancer: A National Cancer Database Study

Objective To determine overall survival (OS) and factors associated with OS after pelvic exenteration for cervical cancer. Methods Women with cervical cancer who underwent exenteration (n = 517) were identified from the 1998 to 2011 National Cancer Database. Kaplan-Meier and multivariate Cox proportional-hazards survival analyses were performed to test for associations of potential explanatory variables with OS. Analyzed confounders included age, insurance status, income, distance from home to treatment center, stage, exenteration type, surgical margin status, and treatment with adjuvant radiation and/or chemotherapy. Results Among the entire cohort with clinical follow-up (n = 313), median OS was 24 months. Stage (P = 2.5 × 10−12), lymph node status (P = 1.3 × 10−7), insurance status (P = 1.5 × 10−5), and histologic type (P = 0.04) were significantly associated with OS by the log-rank test. Unadjusted median OS was 24.2 and 61.8 months for women with squamous and adenocarcinoma histologies, respectively. By multivariate Cox regression, age, insurance status, stage, margin status, and adjuvant radiation were associated with OS. Histology was not independently associated with OS on multivariate regression. Among women with node-negative disease, median OS was 73.2 months. Conclusions Exenteration may be curative for more than half of women with node-negative cervical cancer. Stage, insurance status, lymph node status, and surgical margin are independently associated with differential OS after exenteration.

The Hispanic Paradox in endometrial cancer: A National Cancer Database study

OBJECTIVE To compare the overall survival of non-Hispanic white and Hispanic women with endometrial cancer. METHODS We performed an observational retrospective cohort study of Hispanic and non-Hispanic women with endometrial cancer from the 2004-2014 National Cancer Database. Baseline characteristics were compared with the Chi-squared test for categorical variables or the Mann-Whitney U test for ordinal or continuous variables. The Kaplan-Meier method was used to estimate unadjusted survival times, which were compared with the log-rank test. Missing data was imputed using multiple imputation with chained equations. A multivariable parametric accelerated failure time model for survival was used. Sensitivity analyses were performed using matched cohort analyses of the overall cohort, and of subgroups based on stage or type. RESULTS 112,574 non-Hispanic and 6313 Hispanic women met inclusion criteria. Five-year survival was slightly higher for Hispanic women (83.1% (82.1-84.3%) versus 81.4% (81.2-81.7%), P=0.002). Hispanic women were younger, treated at lower volume hospitals, and more often diagnosed with a type II histology and stage II-IV disease compared to non-Hispanic women (all P<0.001). With multivariable adjustment for measured confounders, Hispanic women lived 8% longer than non-Hispanic women (time-ratio (95% CI) 1.08 (1.02-1.14), P=0.01). When bias-reducing matched cohort analyses were used for sensitivity analyses, Hispanic women did not have significantly different survival than non-Hispanic women. CONCLUSION Hispanic ethnicity was not associated with a clinically meaningful difference in survival among women with endometrial cancer.