The non-vesicle cell-free DNA (cfDNA) induces cell transformation associated with horizontal DNA transfer

BACKGROUND

Cell-free DNA (cfDNA) is a source for liquid biopsy used for cancer diagnosis, therapy selection, and disease monitoring due to its non-invasive nature and ease of extraction. However, cfDNA also participates in cancer development and progression by horizontal transfer. In humans, cfDNA circulates complexed with extracellular vesicles (EV) and macromolecular complexes such as nucleosomes, lipids, and serum proteins. The present study aimed to demonstrate whether cfDNA not associated with EV induces cell transformation and tumorigenesis.

METHODS

Supernatant of the SW480 human colon cancer cell line was processed by ultracentrifugation to obtain a soluble fraction (SF) and a fraction associated with EV (EVF). Primary murine embryonic fibroblast cells (NIH3T3) underwent passive transfection with these fractions, and cell proliferation, cell cycle, apoptosis, cell transformation, and tumorigenic assays were performed. Next, cfDNA was analyzed by electronic microscopy, and horizontal transfer was assessed by human mutant KRAS in recipient cells via PCR and recipient cell internalization via fluorescence microscopy.

RESULTS

The results showed that the SF but not the EVF of cfDNA induced proliferative and antiapoptotic effects, cell transformation, and tumorigenesis in nude mice, which were reduced by digestion with DNAse I and proteinase K. These effects were associated with horizontal DNA transfer and cfDNA internalization into recipient cells.

CONCLUSIONS

The results suggest pro-tumorigenic effects of cfDNA in the SF that can be offset by enzyme treatment. Further exploration of the horizontal tumor progression phenomenon mediated by cfDNA is needed to determine whether its manipulation may play a role in cancer therapy.

Computational Study of the Binding Modes of Diverse DPN Analogues on Estrogen Receptors (ER) and the Biological Evaluation of a New Potential Antiestrogenic Ligand

Estrogen (17β-estradiol) is essential for normal growth and differentiation in the mammary gland. In the last three decades, previous investigations have revealed that Estrogen Receptor Alpha (ERα) plays a critical role in breast cancer. More recently, observations regarding the widespread expression of ERβ-like proteins in normal and neoplastic mammary tissues have suggested that ERβ is also involved in the mentioned pathology. Design of new drugs both steroidal and nonsteroidal that target any of these receptors represents a promise to treat breast cancer although it remains a challenge due to the sequence similarity between their catalytic domains. In this work, we propose a new set of compounds that could effectively target the estrogen receptors ERα and ERβ. These ligands were designed based on the chemical structure of the ERβ-selective agonist Diarylpropionitrile (DPN). The designed ligands were submitted to in silico ADMET studies, yielding in a filtered list of ligands that showed better drug-like properties. Molecular dynamics simulations of both estrogen receptors and docking analysis were carried-out employing the designed compounds, from which two were chosen due to their promising characteristics retrieved from theoretical results (docking analysis or targeting receptor predictions). They were chemically synthetized and during the process, two precursor ligands were also obtained. These four ligands were subjected to biological studies from which it could be detected that compound mol60b dislplayed inhibitory activity and its ability to activate the transcription via an estrogenic mechanism of action was also determined. Interestinly, this observation can be related to theoretical binding free energy calculations, where the complex: ERβ-mol60b showed the highest energy ΔGbind value in comparison to others.

Ultrasound, histopathological, and genetic features of uveal melanoma in a Mexican-Mestizo population

OBJECTIVE

To describe the ultrasound, histopathological and genetic characteristics of uveal melanoma in a Mexican-Mestizo population.

MATERIAL AND METHODS

A total of 39 enucleated eyes with a histopathological diagnosis of uveal melanoma were assessed by describing the clinical findings, and ultrasound, histopathological and genetic features.

RESULTS

A high correlation was observed between tumour height measurement using ultrasound and histopathology. In our cases, tumour size and reflectivity were higher compared with those reported in the literature. The preliminary data on the molecular assessment of the tumours show the presence of an unreported polymorphism (T>C IVS5+34) and one sample with GNAQ mutation (A>C CAA>CCA Gln 209 Pro).

CONCLUSION

Ultrasound is a reliable method to identify the size of the tumour. Furthermore, knowledge of the molecular mechanisms promises new perspectives for the development of new targeted therapeutics. Fortunately this leads to progress in the treatment of patients with metastatic disease or prevents it in those at high risk.

Exploring disparities in incidence and mortality rates of breast and gynecologic cancers according to the Human Development Index in the Pan-American region

OBJECTIVE

To evaluate whether a country's Human Development Index (HDI) can help explain the differences in the country's breast cancer and gynecological cancer incidence and mortality rates in the Pan-American region.

STUDY DESIGN

Ecological analysis.

METHODS

Pan-American region countries with publicly available data both in GLOBOCAN 2012 and the United Nations Development Report 2012 were included (n = 28). Incidence and mortality rates age-standardized per 100,000 were natural log-transformed for breast cancer, ovarian cancer, corpus uteri cancer, and cervical cancer. The mortality-to-incidence ratio (MIR) was calculated for each site. Pearson's correlation test and a simple linear regression were performed.

RESULTS

The HDI showed a positive correlation with breast cancer and ovarian cancer incidence and mortality rates, respectively, and a negative correlation with cervical cancer incidence and mortality rates. The HDI and corpus uteri cancer showed no association. MIR and the HDI showed a negative correlation for all tumor types except ovarian cancer. An increment in 1 HDI unit leads to changes in cancer rates: in breast cancer incidence β = 4.03 (95% confidence interval [CI] 2.61; 5.45) P < 0.001, breast cancer mortality β = 1.76 (95% CI 0.32; 3.21) P = 0.019, and breast cancer-MIR β = -0.705 (95% CI 0.704; 0.706) P < 0.001; in cervical cancer incidence β = -3.28 (95% CI -4.78; -1.78) P < 0.001, cervical cancer mortality β = -4.63 (95% CI -6.10; -3.17) P < 0.001, and cervical cancer-MIR β = -1.35 (95% CI -1.83; -0.87) P < 0.001; in ovarian cancer incidence β = 3.26 (95% CI 1.78; 4.75) P < 0.001, ovarian cancer mortality β = 1.82 (95% CI 0.44; 3.20) P = 0.012, and ovarian cancer-MIR β = 5.10 (95% CI 3.22; 6.97) P < 0.001; in corpus uteri cancer incidence β = 2.37 (95% CI -0.33; 5.06) P = 0.83, corpus uteri cancer mortality β = 0.68 (95% CI -2.68; 2.82) P = 0.96, and corpus uteri cancer-MIR β = -2.30 (95% CI -3.19; -1.40) P < 0.001.

CONCLUSIONS

A country's HDI should be considered to understand disparities in breast cancer and gynecological cancer in the Pan-American region.

Nicotinamide sensitizes human breast cancer cells to the cytotoxic effects of radiation and cisplatin

Poly(ADP-ribose) polymerase (PARP) inhibitors enhance the effect of DNA alkylating agents on BRCA1‑ and BRCA2-deficient cell lines. The aim of this study was to analyze the effect of the PARP inhibitor nicotinamide (NAM) on breast cancer cells with different BRCA1 expression or function, such as BRCA1‑deficient MDA-MB-436 cells, low expression BRCA1 MCF-7 cells, and the BRCA1 wild‑type MDA-MB-231 cells, to demonstrate its effects as a chemo‑ or radiosensitizing agent. PARP activity was analyzed in MDA-MB-436, MCF-7 and MDA-MB-231 breast cancer cells subjected or not to NAM. Inhibition of PARP by NAM in the presence of DNA damage was examined by Alexa Fluor 488 immunofluorescence. Crystal violet assays were used to test growth inhibition and the chemo‑ and radiosensitization effects of NAM were investigated using clonogenic assays. Significant differences among data sets were determined using two-tailed ANOVA and Bonferroni tests. We demonstrated that NAM reduces PARP activity in vitro, and in cells subjected or not to DNA damage, it also reduces the viability of breast cancer cell lines and synergyzes the cytotoxicity of cisplatin in MDA-MB-436 and MCF-7 cells. Downregulation of PARP1 with siRNA led to modest growth inhibition, which was further increased by cisplatin. Nicotinamide also induced radiosensitization in MDA-MB-436 and MDA-MB-231 cells. In conclusion, NAM may be used as a chemo‑ or radiosensitizing agent regardless of the BRCA1 status in breast cancer.

Genetic selection of volunteers and concomitant dose adjustment leads to comparable hydralazine/valproate exposure

WHAT IS KNOWN AND OBJECTIVE

Hydralazine is an inhibitor of DNA methyltransferases, whereas valproate interferes with histone deacetylation. In combination, they show a marked synergism in reducing tumour growth as well as development of metastasis and inducing cell differentiation. Hydralazine is metabolized by the highly polymorphic N-acetyltransferase 2. The current pilot study was performed to analyse the pharmacokinetic parameters of a single dose of hydralazine in 24 h (one tablet with 83 mg for slow acetylators and one tablet with 182 mg for fast acetylators) and three fixed doses of valproate (one tablet of controlled liberation with 700 mg every 8 h) in healthy genetically selected volunteers. Selection was performed based on their NAT2 activity as deduced from their genotype.

METHODS

An open label non-randomized single arm study was conducted in two groups of six healthy volunteers of both genders aged 20-45 years with a body mass index 22·2-26·9 which were classified as fast or slow acetylators after genotyping 3 SNPs that cover 99·9% of the NAT2 variants in the Mexican population. Blood samples were collected predose and serially post-dose in an interval of 48 h. Hydralazine and valproate concentrations were determined by ultra-high performance liquid chromatography (UPLC) coupled to tandem mass spectroscopy (MS/MS).

RESULTS AND DISCUSSION

The AUC0-48 h and Cmax of hydralazine were almost identical (1410 ± 560 vs. 1446 ± 509 ng h/mL and 93·4 ± 16·7 vs. 112·5 ± 42·1 ng/mL) in both groups with NAT2 genotype-adjusted doses, whereas the multidose parameters of valproate were not significantly affected neither by the selection of the NAT2 genotype (AUC0-48 h 2064 ± 455 vs. 1896 ± 185 μg h/mL; Cmax 96·4 ± 21·1 vs. 88·8 ± 7·2 μg/mL, for the fast and slow acetylators, respectively) nor the co-administration of 83 or 182 mg of hydralazine.

WHAT IS NEW AND CONCLUSION

Comparable hydralazine exposures (differences in AUC0-inf of only 7%) were observed in this study with genetic selection of volunteers and concomitant dose adjustment. However, the conclusions have yet to be confirmed with a full-powered 2 × 2 crossover study.

Radiosensitization of cervical cancer cells with epigenetic drugs hydralazine and valproate

PURPOSE

To evaluate the radiosensitizing effects of the DNA methylation inhibitor hydralazine in combination with valproic acid, a histone deacetylase inhibitor in cervical cancer cells.

MATERIALS AND METHODS

Cell viability assays were performed in the SiHa cervical cancer cell line treated with hydralazine and valproic acid for five days with and without cisplatin. Cell irradiation was performed using teletherapy (1.25 MV).

RESULTS

Neither hydralazine, valproic acid or cisplatin as single agents increased the cytotoxicity from radiation, however, the combination of hydralazine with valproic acid at ten microM and one mM, respectively, did induce radiosensitization (p = 0.046). Interestingly, this effect was further increased with the triple combination of hydralazine, valproic acid, and cisplatin (p = 0.041), where cell viability decreased more than 50% as compared to radiation alone.

CONCLUSIONS

The present results demonstrate that epigenetic drugs increase the efficacy of cisplatin chemoradiation in cervical cancer cells.

Upregulation of NKG2D ligands and enhanced natural killer cell cytotoxicity by hydralazine and valproate

Natural killer cells play a role in the immune antitumor response by recognizing and eliminating tumor cells through the engagement of NKG2D receptors with their ligands on target cells. This work aimed to investigate whether epigenetic drugs are able to increase MICA and MICB expression as well as NK cell cytotoxicity. Prostate, colon, breast and cervical cancer cell lines were analyzed for the expression of MICA and MICB at the mRNA and protein levels by RT-PCR, Western blot, flow cytometry and ELISA. The activating mark H3K4m2 at the MICA and MICB promoters was investigated by ChIP assays. Cytotoxicity of NK cells against the target epithelial cancer cells was investigated with the CD107 cytotoxicity assay. The results show that hydralazine and valproic acid not only increase the expression of MICA and MICB ligands of target cells, but also reduce their shedding to the supernatant. This upregulation occurs at the transcriptional level as revealed by increase of the H3K4 activating mark at the promoter of MICA and MICB genes. These effects are paralleled by increased cytotoxicity of NK cells, which was attenuated at different degrees by using blocking antibodies against the NKG2D receptor and ligands. In conclusion, our results demonstrate the ability of hydralazine and valproate to increase the NK activity against epithelial cancer cell lines and suggest that these drugs could reduce the levels of soluble MICA and MICB helping in avoiding tumor-induced suppression of NK cytotoxicity against the tumor.

Epigenetic therapy and cisplatin chemoradiation in FIGO stage IIIB cervical cancer

INTRODUCTION

This trial aimed to evaluate the safety and efficacy of epigenetic therapy associated with cisplatin chemoradiation in FIGO Stage IIIB patients.

METHODS

Hydralazine containing either 182 mg for rapid-, or 83 mg for slow acetylators and magnesium valproate were administered at 30 mg/kg tid. Both drugs were taken until intracavitary therapy was finished. Pelvic external beam radiation and low-dose rate brachytherapy were administered at a total cumulative dose to point A of at least 85 Gy. Weekly cisplatin at 40 mg/m2 was delivered for six cycles.

RESULTS

Twenty-two patients were included and 18 (82%) patients completed treatment. Mean dose to point A was 84.6 + 2.2. Median number of cisplatin cycles was 5.5 (range, 1-6). Brachytherapy was delayed for technical reasons; the mean overall treatment time was 11.8 weeks. Grade 3 anemia, leucopenia, neutropenia, and thrombocytopenia were observed in 9%, 45%, 45%, and 9% of patients, respectively.

CONCLUSIONS

Hydralazine and valproate are well-tolerated and safe when administered with cisplatin chemoradiation. Unfortunately, the suboptimal administration of brachytherapy for technical reasons in this study, precluded assessing the efficacy of epigenetic therapy. However, the tolerability of this regimen administered concurrent to radiation needs to be further tested.

Pharmacogenetics and pharmacoepigenetics of gemcitabine

Gemcitabine (2',2'-difluoro 2'deoxycytidine, dFdC) is an analog of cytosine with distinctive pharmacological properties and a wide antitumor-activity spectrum. The pharmacological characteristics of gemcitabine are unique because two main classes of genes are essential for its antitumor effects: membrane transporter protein-coding genes, whose products are responsible for drug intracellular uptake, as well as enzyme-coding genes, which catalyze its activation and inactivation. The study of the pharmacogenetics and pharmacoepigenetics of these two gene classes is greatly required to optimize the drug's therapeutic use in cancer. This review aims to provide an update of genetic and epigenetic bases that may account for interindividual variation in therapeutic outcome exhibited by gemcitabine.

A phase III study comparing concurrent gemcitabine (Gem) plus cisplatin (Cis) and radiation followed by adjuvant Gem plus Cis versus concurrent Cis and radiation in patients with stage IIB to IVA carcinoma of the cervix

CRA5507

Background: Cervical cancer is the second-most common cancer among women worldwide, in both incidence and mortality. Current standard therapy for locally advanced disease consists of concurrent Cis and external-beam radiation (XRT). This multicenter, open-label, randomized, phase III trial aimed to improve outcomes, capitalizing on the synergistic activity of Gem, Cis, XRT, and the potential value of adjuvant therapy. Methods: Eligible patients (pts) with bulky stage IIB to IVA, 18–70 years of age, chemotherapy- and radiotherapy-naive, with a Karnofsky Performance Status score ≥70, were randomized to Arm A: Cis 40 mg/m2 followed by Gem 125 mg/m2 weekly × 6 doses with concurrent XRT (50.4 Gy: in 28 fractions: 1.8 Gy/day, 5 days/week), followed by brachytherapy (brachy) (30–35 Gy) and then 2 adjuvant 21-day cycles of Gem (1,000 mg/m2 on Days 1 and 8) plus Cis (50 mg/m2 on Day 1); or Arm B: Cis 40 mg/m2 weekly × 6 doses with concurrent XRT followed by brachy, given as in Arm A. Primary endpoint was progression-free survival (PFS) at 3 years, compared between arms using Kaplan-Meier methods and a Z-statistic. Results: 515 pts were enrolled between 5/02 and 3/04 (259 pts Arm A, 256 pts Arm B). Median age was 46 years; stage IIB/IIIB/IVA in 61/37/2% of pts. Compliance in the concurrent and brachy phase was >90% for both arms; adjuvant cycles were completed by >75% of pts in Arm A. PFS at 3 years was 74% in Arm A compared to 65% in Arm B, resulting in a statistically significant improvement (p = 0.029). Overall survival (log-rank p = 0.0224) and time to progressive disease (log-rank p = 0.0008) were also significantly improved. Significantly more pts in Arm A experienced grade 3/4 toxicities (86.5%), compared to pts in Arm B (46.3%; Fisher's p < 0.001). In Arm A, 2 pts died due to causes probably related to treatment compared to 0 pts in Arm B. Conclusions: This novel regimen of concurrent Gem plus Cis and XRT followed by brachy and adjuvant Gem plus Cis significantly improved outcomes in pts with locally advanced carcinoma of the cervix, at the expense of increased but acceptable toxicity, compared to the current standard of care.

[Table: see text]

A phase III study comparing concurrent gemcitabine (Gem) plus cisplatin (Cis) and radiation followed by adjuvant Gem plus Cis versus concurrent Cis and radiation in patients with stage IIB to IVA carcinoma of the cervix

CRA5507

The full, final text of this abstract will be available in Part II of the 2009 ASCO Annual Meeting Proceedings, distributed onsite at the Meeting on May 30, 2009, and as a supplement to the June 20, 2009, issue of the Journal of Clinical Oncology.

[Table: see text]

Mutational analysis of BRCA1 and BRCA2 genes in Mexican breast cancer patients

Germline mutations in the BRCA1 and BRCA2 genes predispose to breast and ovarian cancer. A variable incidence of mutations has been reported for these genes. The contribution of BRCA1 and BRCA2 mutations to Mexican women with breast and/or ovarian cancer is not known. Because of the increasing prevalence of breast cancer in this population, it is necessary to study the presence of mutations in both genes. We screened BRCA1 and BRCA2 genes in 40 patients: 29 patients with a history of breast and/or ovarian cancer, and 11 patients with early-onset breast cancer (< 40 years), through denaturing high performance liquid chromatography analyses. We found two frameshift mutations in BRCA1 and one missense mutation in each gene. Additionally we found several intronic variants as well as synonymous mutations. We found 5% of deleterious mutations in the BRCA genes. Larger studies are needed to establish the significance and prevalence of BRCA mutations among Mexican women.

A phase II study of epigenetic therapy with hydralazine and magnesium valproate to overcome chemotherapy resistance in refractory solid tumors

BACKGROUND

Epigenetic aberrations lead to chemotherapy resistance; hence, their reversal by inhibitors of DNA methylation and histone deacetylases may overcome it.

PATIENTS AND METHODS

Phase II, single-arm study of hydralazine and magnesium valproate added to the same schedule of chemotherapy on which patients were progressing. Schedules comprised cisplatin, carboplatin, paclitaxel, vinorelbine, gemcitabine, pemetrexed, topotecan, doxorubicin, cyclophosphamide, and anastrozole. Patients received hydralazine at 182 mg for rapid, or 83 mg for slow, acetylators, and magnesium valproate at 40 mg/kg, beginning a week before chemotherapy. Response, toxicity, DNA methylation, histone deacetylase activity, plasma valproic acid, and hydralazine levels were evaluated.

RESULTS

Seventeen patients were evaluable for toxicity and 15 for response. Primary sites included cervix (3), breast (3), lung (1), testis (1), and ovarian (7) carcinomas. A clinical benefit was observed in 12 (80%) patients: four PR, and eight SD. The most significant toxicity was hematologic. Reduction in global DNA methylation, histone deacetylase activity, and promoter demethylation were observed.

CONCLUSIONS

The clinical benefit noted with the epigenetic agents hydralazine and valproate in this selected patient population progressing to chemotherapy' and re-challenged with the same chemotherapy schedule after initiating hydralazine and valproate' lends support to the epigenetic-driven tumor-cell chemoresistance hypothesis (ClinicalTrials.gov Identifier: NCT00404508).

The prognostic significance of leukocytosis in cervical cancer

Cervical cancer is a frequent tumor with established prognostic factors such as FIGO stage and hemoglobin levels among others. Despite the fact that paraneoplastic leukocytosis is relatively common in many solid tumors, only isolated cases of cervical cancer patients presenting this abnormality have been published; hence, the clinical significance of leukocytosis is unknown in this tumor type. Retrospective review on the medical records of 294 consecutive newly diagnosed and untreated locally advanced cervical cancer patients who received radiotherapy and concurrent cisplatin was conducted. Leukocytosis was defined as a persistent white blood cell count exceeding 10,800/microL, determined at least twice before commencing chemoradiation providing that patients were free of any active acute or chronic infection or any other condition known to elevate the leukocyte count. The frequency of leukocytosis and their correlation with clinicopathologic features were investigated, as well as their impact on tumor response and survival. Leukocytosis with a median value of 13,300/microL (11,100-28,800) was observed in 35 (11.9%) patients at diagnosis. Leukocytosis was statistically associated only with advanced stages. Clinical complete response was observed in 57% versus 86% of the patients with and without leukocytosis, respectively. In the univariate analysis, leukocytosis, stage, and hemoglobin levels were significant predictors of survival; however, only leukocytosis and the hemoglobin level remained significant predictors of survival in the multivariate analysis. Leukocytosis is common in cervical cancer patients and has a negative prognostic significance.

A phase II trial of epigenetic therapy with hydralazine and magnesium valproate associated to doxorubicin and cyclophosphamide for locally advanced breast cancer

13147

Background: DNA methylation and histone deacetylation are the most studied epigenetic alterations in cancer. Hydralazine and magnesium valproate are proven DNA methylation and histone deacetylase inhibitors respectively that in combination exert antitumor effects by their own and potentate the effect of chemotherapy. Methods: Open label two-stage design phase II trial to evaluate safety and efficacy of hydralazine and magnesium valproate plus chemotherapy in terms of pathologic complete response as neoadjuvant treatment. A total of 42 patients will be accrued. Untreated patients with histological confirmation of breast cancer in clinical stage IIb-IIIa, and hematological, renal and hepatic normal function are elegible. Patients with any collagen disease and any cardiovascular condition were excluded. Treatment consisted on four 21-day courses of doxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2 plus epigenetic therapy starting 7 days before the first cycle of chemotherapy and continued until the end of chemotherapy. Oral hydralazine dosed according to acetylator phenotype and magnesium valproate at 30mg/Kg. After chemotherapy patients were evaluated with mammography and then submitted to surgical resection. Results: 17 patients in the first-stage have been accrued. Their characteristics are as follows: Median age 45-y (39–67), 67% were stage IIIa, median size of tumor was 5 cm (3–10 cm). All patients had clinically positive axillary nodes, with median size of 2 cm (1–5 cm), 80% were ductal carcinomas and 80% had either intermediate or high grade; 77% were ER-positive and 30% over-expressed HER2. Hematological toxicity was the most common side effect, neutropenia grade 3/4 was found in 35% of cases, anemia grade 3/4 was present in 15% of cases and most presented transient grade 2 depressed level of consciousness. Seven patients have completed planned treatment, clinical responses were CR 2, PR 4 and SD 1; in 1 of 7 a pathological complete response was seen. Conclusions: Epigenetic therapy with hydralazine and magnesium valproate associated to conventional chemotherapy is well tolerated. Its antitumor efficacy is pending to evaluate.

No significant financial relationships to disclose.

Phase II trial of gemcitabine concurrent with radiation for locally advanced squamous cell carcinoma of the head and neck

BACKGROUND

Concurrent chemoradiation is the current standard of treatment for patients with advanced unresectable head and neck squamous cell carcinoma (HNSCC). Due to the potent radiosensitizing properties of gemcitabine, we decided to assess its efficacy and toxicity with concurrent radiation in patients with advanced HNSCC.

PATIENTS AND METHODS

From January 1997 to December 2001, 27 patients with locally advanced HNSCC (stage III, 37%; stage IV, 63%) were enrolled. All received a course of radiotherapy (70 Gy over 7 weeks) concurrent with weekly infusions of gemcitabine at 100 mg/m2 or 50 mg/m2.

RESULTS

All patients were assessable for toxicity and 26 for response. Severe mucositis (grade 3-4) was observed in 74% of patients (grade 4, 41%). Severe hematological toxicity was uncommon. Mild and moderate xerostomy was the most common late toxicity in 23 patients (85%). The median radiation dose delivered was 70 Gy (40-80 Gy), 25 patients (93%) received > or = 80% of the intended dose. Gemcitabine dose intensity was > or = 80% in only 13 (48%) patients. The rate of complete and partial responses were 61% and 27%, respectively, for an overall response rate of 88%. At a median follow-up of 13 months (range 6-62), the actuarial 3-year progression-free survival (PFS) and overall survival (OS) were 37% and 33%, respectively. The only variable associated with prolonged survival (P = 0.0001) was the degree of response. No difference was observed in response or toxicity with either gemcitabine 50 or 100 mg/m2.

CONCLUSIONS

The concurrent use of radiotherapy and gemcitabine is effective but produces manageable severe mucositis in a high percentage of patients.

Correlation of tumor growth index with early treatment response in cervical carcinoma

Despite the recent progress in the management of cervical carcinoma, treatment failure is quite common and therefore it is necessary to identify predicting factors for tumor response. It is known that both cell proliferation and apoptosis determine the tumor growth index (TGI) which reflects the overall contribution of gene defects. Here we explored whether the TGI index could be a better predictor of response in comparison to cell proliferation or apoptosis as separate phenomena. Twenty-five patients with cervical carcinoma treated with radiation alone or neoadjuvant chemotherapy plus surgery were analyzed. Cell proliferation and apoptosis determined by PCNA immunohistochemical expression and tumor nucleosomes by ELISA, respectively, were used to calculate the TGI, which was analyzed with regard to early tumor response. Our results show that most patients with a negative TGI had early response suggesting increased tumor sensitivity(p = 0.0186). On the other hand, patients with a positive TGI were more resistant to treatment. TGI was not related to age, clinical stage or tumor size. In conclusion, the results of this study show that the determination of the TGI, but no cell proliferation or apoptosis, as separate events, is able to predict an early treatment response to either radiation or chemotherapy in cervical carcinoma.

Membrane proteins in neoplasic and normal uterine cervix

Tumor cells exhibit phenotypic and genotypic differences in comparison to normal cells. These differences can be used to identify proteins important for tumor growth and, therefore, potentially used in the diagnosis and follow-up of patients. The objective of this work was to investigate the electrophoretic pattern of cytoplasm membrane proteins from normal and malignant cervix using polyacrylamide-SDS gels. A highly reproducible protein pattern was found in the 29 samples of normal cervix whereas three well-defined patterns of protein bands were observed in the 48 tumor specimens (pattern I: 25%, pattern II: 29.2% and pattern III: 45.8%). A low concentration or absence of high molecular weight proteins was observed (p<0.5) in tumor samples. None of the tumor protein patterns correlated with the clinicopathologic characteristics of patients. Nine out of 11 patients (82%) showing the pattern III had a complete clinical response whereas only 55% (11 out of 20) of those with patterns I and II showed a complete response. However, this difference was non-significant (p=0.1247). In conclusion, we demonstrate that there is a gain and loss of cytoplasmic membrane proteins in tumors, shown as different protein band patterns. These findings could have clinical and biological significance that must be further evaluated.

Immunohistochemical expression of p53 in breast carcinoma is associated with the intron 1 BglII polymorphism of the p53 gene

Breast carcinoma is a public health problem worldwide. It is known that both genetic and environmental factors are important for breast carcinogenesis and that structural and/or functional alterations at p53 gene are commonly observed in breast tumors. In addition, polymorphisms of several genes in either their coding or non-coding sequences have been found related to cancer risk and/or clinicopathological characteristics of tumors. In this study we have evaluated the intron 1 BglII polymorphism of the p53 gene with a PCR-based approach in 117 cases of breast cancer and 102 healthy women and its association with the immunohistochemical expression of p53 in the tumors. The results showed that the presence of the polymorphism (allele 2) is highly associated with the tumor expression of p53 (p<0.0001) and that there is a trend for increased frequency of allele 2 in cases than in controls (p=0.2376). These data suggest that the germ-line variation in the intron 1 of the p53 gene could produce functional or structural changes of the protein that is reflected by its abnormal expression.

Adjuvant high-dose chemotherapy supported by peripheral blood stem cell transplantation for high-risk cervical carcinoma

Cervical carcinoma is a common disease for which the prognosis has not been substantially improved with standard locoregional treatments. Three stage IB patients with untreated cervical carcinoma were treated with high-dose chemotherapy and refrigerated peripheral blood stem cell support using the ICE program (Ifosfamide 10 g/m2 plus mesna at 100% of the ifosfamide dose; Carboplatin at 1.5 g/m2 and Etoposide 2.1 g/m2). Patients received the treatment in an adjuvant setting after radical hysterectomy with pelvic lymph-node dissection and postoperative cisplatin-based standard-dose chemotherapy. All patients underwent postoperative radiotherapy. The treatment was well-tolerated, all patients had rapid hematologic recovery, and the most frequent complications were grade 3 mucositis and neutropenic fever. The three patients are disease-free at 58, 60, and 63 months of follow-up. Our results show that adjuvant high-dose chemotherapy could be effective to reduce the likelihood of relapse in high-risk patients. High-dose chemotherapy deserves a formal evaluation in high-risk cervical cancer.

Bioavailability of etoposide after oral administration of the solution marketed for intravenous use: therapeutic and pharmacoeconomic perspectives

BACKGROUND

Oral etoposide administration is a suitable alternative to the intravenous route; therefore, commercial capsules have been developed. Before these capsules were available in Mexico, we studied drug bioavailability after oral administration of the intravenous etoposide solution (IVES).

METHODS

Eight adult cancer patients received a 50-mg oral etoposide dose as IVES and blood samples were collected over a period of 24 h. Plasma etoposide concentration was determined by high-performance liquid chromatography, plasma concentration against time curves were constructed, and bioavailability parameters were calculated.

RESULTS

Oral IVES yielded an adequate bioavailability profile because Cmax was 2.38 +/- 0.30 micrograms/mL, AUC was 12.87 +/- 2.02 micrograms/mL and half-life was 6.72 +/- 0.97 h.

CONCLUSIONS

Considering that the pharmacokinetic aim is to maintain plasma concentrations between 0.5 and 1.0 microgram/mL for several hours while avoiding high concentrations, i.e., of 10 micrograms/mL or higher, oral administration of 50-mg etoposide as IVES appears to be a suitable dosing option. In addition, oral IVES is considerably less expensive than intravenous administration in terms of both drug presentation and administration.

Analysis of bcl-2 in sporadic breast carcinoma

BACKGROUND

The bcl-2 gene encodes a protein that blocks apoptosis and might help to promote tumor development. It is expressed in a high percentage of breast tumors and is associated with good prognostic features. However, the mechanisms that regulate bcl-2 expression in breast carcinoma are unknown. Moreover, immunohistochemical detection of bcl-2 is related inversely to p53 expression. This notwithstanding, the immunohistochemical detection of p53 does not always correlate with the detection of p53 gene mutations. The authors studied the molecular organization of bcl-2 as well as the methylation status of its CpG island and analyzed the correlation between bcl-2 expression and p53 gene mutations.

METHODS

The molecular organization of the bcl-2 gene and the methylation pattern of its CpG island were analyzed by Southern blot analysis. In addition, immunohistochemical analysis of bcl-2 and p53 protein expression was performed. Finally, the presence of mutations at exons 5-9 of the p53 gene were analyzed by polymerase chain reaction and single-strand conformation polymorphism.

RESULTS

No molecular abnormality was found at the bcl-2 locus in cases of sporadic breast carcinoma. Moreover, loss of heterozygosity analysis failed to detect any allelic loss in the study cases. It also was found that the bcl-2 CpG island was demethylated in all cases. These results point to a lack of correlation between bcl-2 protein expression and the presence of p53 gene mutations.

CONCLUSIONS

The level of bcl-2 expression in breast carcinoma is not associated with any somatic abnormality or epigenetic change at the bcl-2 locus. Conversely, although bcl-2 expression is related inversely to p53 protein expression, the analysis of p53 mutations (limited to exons 5-9) failed to demonstrate any relationship between p53 mutations and bcl-2 protein expression.

Analysis of nm23-H1 expression in breast cancer. Correlation with p53 expression and clinicopathologic findings

Metastasis is the most frequent cause of death in patients with breast cancer. The nm23-H1 and p53 genes have been involved in the development of breast cancer metastasis. We have analyzed the correlation between the expression of nm23 protein and several established clinicopathologic factors. Our results show that the antimetastatic role of nm23-H1 is not related to the cell proliferative status or tumor grade and that it is not associated with the expression of p53. We also demonstrate a strong inverse relationship between the expression of nm23-H1 protein, lymph node metastasis and vascular invasion. These data support the antimetastatic role of the nm23-H1 gene and suggest that nm23-H1 and p53 genes may be involved in different steps of the metastatic process.