Persistence of cisplatin-induced mutagenicity in hematopoietic stem cells: implications for secondary cancer risk following chemotherapy

Rare Earth and Platinum Group Elements In Sub-Saharan Africa and Global Health: The Dark Side of the Burgeoning of Technology

Despite steady progress in the development and promotion of the circular economy as a model, an overwhelming proportion of technological devices discarded by the Global North still finds its way to the Global South, where technology-related environmental health problems start from the predation of resources and continue all the way to recycling and disposal. We reviewed literature on TCEs in sub-Saharan Africa (SSA), focussing on: the sources and levels of environmental pollution; the extent of human exposure to these substances; their role in the aetiology of human diseases; their effects on the environment. Our review shows that even minor and often neglected technology-critical elements (TCEs), like rare earth elements (REEs) and platinum group elements (PGEs), reveal the environmental damage and detrimental health effects caused by the massive mining of raw materials, exacerbated by improper disposal of e-waste (from dumping to improper recycling and open burning). We draw attention of local research on knowledge gaps such as workable safer methods for TCE recovery from end-of-life products, secondary materials and e-waste, environmental bioremediation and human detoxification. The technical and political shortcomings in the management of TCEs in SSA is all the more alarming against the background of unfavourable determinants of health and a resulting higher susceptibility to diseases, especially among children who work in mines and e-waste recycling sites or who reside in dumping sites.This paper demonstrates, for the first time, that the role of unjust North-South dynamics is evident even in the environmental levels of minor trace elements and that the premise underlying attempts to solve the problem of e-waste dumped in Africa through recycling and disposal technology is in fact misleading. The influx of foreign electrical and electronic equipments should be controlled and limited by clearly defining what is a 'useful' second-hand device and what is e-waste; risks arising from device components or processing by-products should be managed differently, and scientific uncertainty and One Health thinking should be incorporated in risk assessment.

Incidence of Secondary Cancers After Neoadjuvant Therapy for Locally Advanced Rectal Cancer

INTRODUCTION

Whether neoadjuvant chemoradiation for locally advanced rectal cancer (LARC) induces secondary cancers is controversial. This retrospective cohort study describes the incidence of secondary cancers in LARC patients.

METHODS

We compared 364 LARC patients who received conventional (50.4 Gy) or short course neoadjuvant radiation (25 Gy x 5 fractions) followed by resection to 142 patients with surgically resected rectal cancer who did not receive radiation at a single institution from 2004 to 2018. Secondary cancer was defined as any nonmetastatic noncolorectal malignancy diagnosed via biopsy or definitive imaging criteria at least 6 mo after completion of neoadjuvant therapy or after resection in the comparison group.

RESULTS

Among the neoadjuvant radiation group (364 patients, 40% female, age 61 ± 13 y), 32 patients developed 34 (9.3%) secondary cancers. Three cases involved a pelvic organ. Among the comparison group (142 patients, 39% female, age 64 ± 15 y), 15 patients (10.6%) developed a secondary cancer. Five cases involved pelvic organs. Secondary cancer incidence did not differ between groups. Latency period to secondary cancer diagnosis was 6.7 ± 4.3 y. Patients who received radiation underwent longer median follow-up (6.8 versus 4.5 y, P < 0.01) and were significantly less likely to develop a pelvic organ cancer (odds ratio 0.18; 95% confidence interval, 0.04-0.83; P = 0.02). No genetic mutations or cancer syndromes were identified among patients with secondary cancers.

CONCLUSIONS

Neoadjuvant chemoradiation is not associated with increased secondary cancer risk in LARC patients and may have a local protective effect on pelvic organs, especially prostate. Ongoing follow-up is critical to continue risk assessment.

Erythrocyte PIG-A mutant frequencies in cancer patients receiving cisplatin

BACKGROUND

Cisplatin is a primary chemotherapy choice for various solid tumors. DNA damage caused by cisplatin results in apoptosis of tumor cells. Cisplatin-induced DNA damage, however, may also result in mutations in normal cells and the initiation of secondary malignancies. In the current study, we have used the erythrocyte PIG-A assay to evaluate mutagenesis in non-tumor hematopoietic tissue of cancer patients receiving cisplatin chemotherapy.

METHODS

Twenty-one head and neck cancer patients undergoing treatment with cisplatin were monitored for the presence of PIG-A mutant total erythrocytes and the young erythrocytes, reticulocytes (RETs), in peripheral blood for up to five and a half months from the initiation of the anti-neoplastic chemotherapy.

RESULTS

PIG-A mutant frequency (MF) in RETs increased at least two-fold in 15 patients at some point of the monitoring, while the frequency of total mutant RBCs increased at least two-fold in 6 patients. A general trend for an increase in the frequency of mutant RETs and total mutant RBCs was observed in 19 and 18 patients, respectively. Only in one patient did both RET and total RBC PIG-A MFs did not increase at any time-point over the monitoring period.

CONCLUSION

Cisplatin chemotherapy induces moderate increases in the frequency of  PIG-A mutant erythrocytes in head and neck cancer patients. Mutagenicity measured with the flow cytometric PIG-A assay may serve as a tool for predicting adverse outcomes of genotoxic antineoplastic therapy.

Gallic acid: a polyphenolic compound potentiates the therapeutic efficacy of cisplatin in human breast cancer cells

Gallic acid (GA) is a natural polyhydroxyphenolic compound with antioxidant, antimutagenic, anti-inflammatory, and antineoplastic activities. Cisplatin (CPT) is a platinum-based chemotherapeutic drug, and it is the treatment of choice for breast, ovarian, testicular, head, and neck cancers. However, the use of anticancer drugs has undesirable effects on patients due to associated toxicities. Thus, it is necessary to search for alternatives that reduce unintended side effects and enhance anticancer potential. The use of natural compounds with the conventional chemotherapeutic drug is a new aspect of cancer therapy. In the present study, we evaluated the ability of GA in the modulation of anticancer effects of CPT in human breast adenocarcinoma cells (MCF-7) by performing MTT, apoptosis, clonogenic cell survival, and micronucleus assays. GA and CPT showed significant cytotoxic activities in MCF-7 cells in a dose-dependent manner. In combination therapy (GA 2.5, 5.0, and 10 μg/mL + CPT10 μg/mL), GA synergistically reduced the MCF-7 cell viability in contrast to the individual therapies. Cancer cells death by GA is through the induction of apoptosis as observed in the acridine orange and ethidium bromide dual staining method. The frequency of micronuclei (MN) was decreased significantly (P < 0.001) in combinational therapy, possibly reducing the risk of chemotherapy-induced MN. Moreover, GA in mono or combinational therapy did not induce any cytotoxic effects in normal breast epithelial cells (MCF-10A). GA did not show any significant difference in colony inhibition compared to CPT. This outcome shows its differential effects in normal and cancerous cells. Hence, the combination GA with chemotherapeutic drugs could represent a promising alternative therapy in cancer treatment with minimal side effects.

Lack of hydroxyurea-associated mutagenesis in pediatric sickle cell disease patients

Hydroxyurea is approved for treating children and adults with sickle cell anemia (SCA). Despite its proven efficacy, concerns remain about its mutagenic and carcinogenic potential that hamper its widespread use. Cell culture- and animal-based investigations indicate that hydroxyurea's genotoxic effects are due to indirect clastogenicity in select cell types when high dose and time thresholds are exceeded (reviewed by Ware & Dertinger, 2021). The current study extends these preclinical observations to pediatric patients receiving hydroxyurea for treatment of SCA. First, proof-of-principle experiments with testicular cancer patients exposed to a cisplatin-based regimen validated the ability of flow cytometric blood-based micronucleated reticulocyte (MN-RET) and PIG-A mutant reticulocyte (MUT RET) assays to detect clastogenicity and gene mutations, respectively. Second, these biomarkers were measured in a cross-sectional study with 26 SCA patients receiving hydroxyurea and 13 SCA patients without exposure. Finally, a prospective study was conducted with 10 SCA patients using pretreatment blood samples and after 6 or 12 months of therapy. Cancer patients exposed to cisplatin exhibited increased MN-RET within days of exposure, while the MUT RET endpoint required more time to reach maximal levels. In SCA patients, hydroxyurea induced MN-RET in both the cross-sectional and prospective studies. However, no evidence of PIG-A gene mutation was found in hydroxyurea-treated children, despite the fact that the two assays use the same rapidly-dividing, highly-exposed cell type. Collectively, these results reinforce the complementary nature of MN-RET and MUT RET biomarkers, and indicate that hydroxyurea can be clastogenic but was not mutagenic in young patients with SCA.

Secondary cancers after carbon-ion radiotherapy and photon beam radiotherapy for uterine cervical cancer: A comparative study

BACKGROUND

There are limited studies on the risk of secondary cancers after carbon-ion radiotherapy (CIRT). We assessed the incidence of secondary cancers in patients treated with CIRT for cervical cancer. We also evaluated the incidence of secondary cancers in patients who received standard photon radiotherapy (RT) throughout the same period.

METHODS

This retrospective study included patients with cervical cancer who underwent curative RT at our hospital. All cancers discovered for the first time after RT were classified as secondary cancers. To compare the risk of secondary cancers among cervical cancer survivors to the general population, standardized incidence ratios (SIRs) were calculated.

RESULTS

The analysis included a total of 197 and 417 patients in the CIRT and photon RT groups, respectively. The total person-years during the observation period were 1052.4 in the CIRT group and 2481.5 in the photon RT group. The SIR for all secondary cancers was 1.1 (95% confidence interval [CI], 0.6-2.1) in the CIRT group and 1.4 (95% CI, 1.0-2.1) in the photon RT group. The 10-year cumulative incidence of all secondary cancers was 9.5% (95% CI, 4.0-21.5) in the CIRT group and 9.4% (95% CI, 6.2-14.1) in the photon RT group. The CIRT and photon RT groups were not significantly different in incidence (p = 0.268).

CONCLUSIONS

The incidence of secondary cancers after CIRT for cervical cancer was similar to that after photon RT. Validation of our findings after long-term observation is warranted.

Evaluation of PIG-A-mutated granulocytes and ex-vivo binucleated micronucleated lymphocytes frequencies after breast cancer radiotherapy in humans

Although the PIG-A gene mutation frequency (MF) is considered a good proxy to evaluate the somatic MF in animals, evidence remains scarce in humans. In this study, a granulocyte PIG-A-mutant assay was evaluated in patients undergoing radiation therapy (RT) for breast cancer. Breast cancer patients undergoing adjuvant RT were prospectively enrolled. RT involved the whole breast, with (WBNRT) or without (WBRT) nodal area irradiation. Blood samples were obtained from participants before (T0) RT, and T1, T2, and T3 samples were collected 3 weeks after the initiation of RT, at the end of RT, and at least 10 weeks after RT discontinuation, respectively. The MF was assessed using a flow cytometry protocol identifying PIG-A-mutant granulocytes. Cytokinesis-blocked micronucleated lymphocyte (CBML) frequencies were also evaluated. Thirty patients were included, and five of them had received chemotherapy prior to RT. The mean (±SD) PIG-A MFs were 7.7 (±12.1) per million at T0, 5.2 (±8.6) at T1, 6.4 (±8.0) at T2 and 3.8 (±36.0) at T3. No statistically significant increases were observed between the PIG-A MF at T0 and the MFs at other times. RT significantly increased the CBML frequencies: 7.9 ‰ (±3.1‰) versus 33.6‰ (±17.2‰) (p < .0001). By multivariate analysis, the CBML frequency was correlated with age at RT initiation (p = .043) and irradiation volume at RT discontinuation (p = .0001) but not with chemotherapy. RT for breast cancer therapy failed to induce an increase in the PIG-A MF. The PIG-A assay in humans needs further evaluation, in various genotoxic exposures and including various circulating human cells.

Drug-Related Carcinogenesis: Risk Factors and Approaches for Its Prevention

The review summarizes the data on the role of metabolic and repair systems in the mechanisms of therapy-related carcinogenesis and the effect of their polymorphism on the cancer development risk. The carcinogenic activity of different types of drugs, from the anticancer agents to analgesics, antipyretics, immunomodulators, hormones, natural remedies, and non-cancer drugs, is described. Possible approaches for the prevention of drug-related cancer induction at the initiation and promotion stages are discussed.

Assessment of Pig-a, Micronucleus, and Comet Assay Endpoints in Tg.RasH2 Mice Carcinogenicity Study of Aristolochic Acid I

A newly developed in vivo Pig-a gene mutation assay displays great potential for integration into genotoxicity tests. To obtain more evidence for application of the Pig-a assay, we integrated this assay, micronucleus test in peripheral blood (MN-pb test) and bone marrow (MN-bm test), as well as a Comet assay into a transgenic RasH2 mice carcinogenicity study. Fourteen male RasH2 mice and five wild-type (WT) mice were treated with a strong mutagen aristolochic acid I at a dose of 5 mg/kg/day for 4 consecutive weeks. Mice recovered in 5 weeks. Peripheral bloods were collected for Pig-a assay, MN-pb test, and Comet assay at several time points, while bone marrow and target organs were harvested for the MN-bm test and pathological diagnosis after mice were euthanized. Finally, 13 of the 14 RasH2 mice developed squamous cell carcinomas in the forestomach, while there were no carcinomas in the WT mice. Pig-a mutant frequencies (MFs) consecutively increased throughout the study to a maximum value of approximately 63-fold more than background. These frequencies were relative to the incidence, size, and malignant degree of tumors. Micronucleated reticulocytes increased from Day 1 to Day 49, before returning to background levels. No positive responses were observed in either the MN-bm test or the Comet assay. Results suggested that, when compared with the other two tests, the Pig-a assay persistently contributed to sustaining MFs, enhanced detection sensitivity due to the accumulation of Pig-a mutations, and demonstrated better predictability for tumorigenicity. Environ. Mol. Mutagen. 61:266-275, 2020. © 2019 Wiley Periodicals, Inc.

3Rs friendly study designs facilitate rat liver and blood micronucleus assays and Pig-a gene mutation assessments: Proof-of-concept with 13 reference chemicals

Regulatory guidance documents stress the value of assessing the most appropriate endpoints in multiple tissues when evaluating the in vivo genotoxic potential of chemicals. However, conducting several independent studies to evaluate multiple endpoints and/or tissue compartments is resource intensive. Furthermore, when dependent on visual detection, conventional approaches for scoring genotoxicity endpoints can be slow, tedious, and less objective than the ideal. To address these issues with current practices we attempted to (1) devise resource sparing treatment and harvest schedules that are compatible with liver and blood micronucleus endpoints, as well as the Pig-a gene mutation assay, and (2) utilize flow cytometry-based methods to score each of these genotoxicity biomarkers. Proof-of-principle experiments were performed with 4-week-old male and female Crl:CD(SD) rats exposed to aristolochic acids I/II, benzo[a]pyrene, cisplatin, cyclophosphamide, diethylnitrosamine, 1,2-dimethylhydrazine, dimethylnitrosamine, 2,6-dinitrotoluene, hydroxyurea, melphalan, temozolomide, quinoline, or vinblastine. These 13 chemicals were each tested in two treatment regimens: one 3-day exposure cycle, and three 3-day exposure cycles. Each exposure, blood collection, and liver harvest was accomplished during a standard Monday-Friday workweek. Key findings are that even these well-studied, relatively potent genotoxicants were not active in both tissues and all assays (indeed only cisplatin was clearly positive in all three assays); and whereas the sensitivity of the Pig-a assay clearly benefitted from three versus one treatment cycle, micronucleus assays yielded qualitatively similar results across both study designs. Collectively, these results suggest it is possible to significantly reduce animal and other resource requirements while improving assessments of in vivo genotoxicity potential by simultaneously evaluating three endpoints and two important tissue compartments using fit-for-purpose study designs in conjunction with flow cytometric scoring approaches. Environ. Mol. Mutagen., 60:704-739, 2019. © 2019 Wiley Periodicals, Inc.

Transformation of follicular lymphoma to double-hit lymphoma during adjuvant chemotherapy for concurrent ovarian carcinoma

The frequency of multiple primary malignant neoplasms (MPMN) is increasing due to population aging. Since consensus guidelines for the treatment of MPMN are lacking, treatment strategies are determined by disease status on a per-patient basis. In this report, we describe a case of MPMN with follicular lymphoma (FL) grade 1 that transformed to double-hit lymphoma during adjuvant chemotherapy for concurrent ovarian carcinoma. A 64-year-old woman was diagnosed with MPMN of FL and endometrioid carcinoma by staging laparotomy and lymph node biopsy. She received four cycles of adjuvant chemotherapy (carboplatin and paclitaxel) for endometrioid carcinoma, but during chemotherapy, the FL grade 1 transformed to double-hit lymphoma. We speculate that adjuvant chemotherapy for endometrioid carcinoma may have triggered the transformation of FL in the present case.

Genoprotective effects of gallic acid against cisplatin induced genotoxicity in bone marrow cells of mice

Chemotherapeutic drugs are used for the treatment of cancer. However, the use of these drugs is limited due to their side effects on normal cells. One of the measures to detect chemoprotection of plant extracts is to evaluate their anticlastogenic effects. In this study, we report the anticlastogenic effect of gallic acid (GA) against cisplatin (Csp), a chemotherapeutic drug, in Swiss albino mice. Three different doses of GA (100, 200 and 400 mg per kg bw) were administered orally to the experimental animals in 0.2 mL quantity for 5 days at 24 hour intervals. Cisplatin, the positive control agent (10 mg per kg bw), was administered intraperitoneally (i.p.) in 0.1 mL quantity. Overall, the results showed that the pretreatment of GA caused a remarkable decrease in Csp induced micronucleus frequency and DNA damage in bone marrow cells of mice. The results suggest that GA showed potent antigenotoxic effects against Csp induced damage in mice bone marrow cells.

Phyllanthus emblica Linn. fruit extract potentiates the anticancer efficacy of mitomycin C and cisplatin and reduces their genotoxicity to normal cells in vitro

OBJECTIVE

Fruit of Phyllanthus emblica Linn. (PE) is widely consumed as a functional food and used as a folk medicine due to its remarkable nutritional and pharmacological effects. Mitomycin C (MMC) and cisplatin (cDDP) are the most widely used forms of chemotherapeutic drug, but their clinical use is limited by their genotoxicity to normal cells. We aimed to determine whether PE has potential to reduce the genotoxicity, while improving the anticancer effect, of MMC and cDDP.

METHODS

Cell proliferation was evaluated using the trypan blue exclusion assay and colony-forming assay. Genomic instability (GIN) was measured using the cytokinesis-block micronucleus assay.

RESULTS

Co-treatment (72 h) with PE at 20-320 μg/ml significantly enhanced the efficacy of MMC (0.05 μg/ml) and cDDP (1 μg/ml) against Colo205 colorectal cancer cells (P<0.05), and at 80-320 μg/ml significantly decreased MMC- and cDDP-induced GIN and multinucleation in normal colonic NCM460 cells (P<0.05). PE significantly decreased the mitotic index (P<0.01), blocked mitotic progression (P<0.05), and promoted apoptosis (P<0.01) in MMC- and cDDP-treated NCM460 cells, suggesting that PE-mediated inhibition of mitosis and induction of apoptosis may limit the division and survival of highly damaged cells. Also, PE was found to inhibit the clonal expansion of MMC- and cDDP-treated NCM460 cells (P<0.05) and decrease the heterogeneity of the surviving clones.

CONCLUSIONS

PE potentiates the anticancer efficacy of MMC and cDDP, while preventing their genotoxicity and inhibiting clonal expansions of unstable genomes in normal cells. These data suggest that PE has the potential to reduce the risk of secondary cancers induced by chemotherapeutics.

Assessment of bendamustine-induced genotoxicity in eukaryotic cells

Bendamustine, an anticancer drug with alkylating properties, is widely used to treat hematological malignancies. Since the nitrogen mustard family alkylators induce DNA damages and have been associated with an elevated risk of second malignancy, current study evaluates the cytotoxic, mutagenic, and recombinogenic effects of bendamustine by using, respectively the mitotic index assay, the in vitro mammalian cell micronucleus test (Mnvit) and the chromosome aberration (CA) test in human peripheral lymphocytes, and the in vivo homozygotization assay in Aspergillus nidulans, which detects the loss of heterozygosity (LOH) due to somatic recombination. Bendamustine (6.0 µg/ml, 9.0 µg/ml, and 12.0 µg/ml) induced a statistically significant concentration-related increase in the frequencies of micronuclei and a significant reduction in the cytokinesis block proliferation index (CBPI) rates when compared to negative control. In the CA test, bendamustine significantly increased the frequencies of structural aberrations at the three tested concentrations when compared to the negative control. Aspergillus nidulans diploids, obtained after bendamustine treatment (6.0 µg/ml, 12.0 µg/ml, and 24.0 µg/ml), produced, after haploidization, homozygotization index (HI) rates higher than 2.0 and significantly different from the negative control. Since bendamustine showed genotoxic effects in all tested concentrations, two of them corresponding to the peak plasma concentrations observed in cancer patients treated with bendamustine, data provided in the current research work may be useful to identify the most appropriate dosage regimen to achieve the efficacy and safety of this anticancer medication.

Enhancer dysfunction in leukemia

Hematopoietic cancers are often initiated by deregulation of the transcriptional machinery. Prominent among such regulators are the sequence-specific DNA-binding transcription factors (TFs), which bind to enhancer and promoter elements in the genome to control gene expression through the recruitment of cofactors. Remarkably, perturbing the function of even a single TF or cofactor can modulate the active enhancer landscape of a cell; conversely, knowledge of the enhancer configuration can be used to discover functionally important TFs in a given cellular process. Our expanding insight into enhancer function can be attributed to the emergence of genome-scale measurements of enhancer activity, which can be applied to virtually any cell type to expose regulatory mechanisms. Such approaches are beginning to reveal the abnormal enhancer configurations present in cancer cells, thereby providing a framework for understanding how transcriptional dysregulation can lead to malignancy. Here, we review the evidence for alterations in enhancer landscapes contributing to the pathogenesis of leukemia, a malignancy in which enhancer-binding proteins and enhancer DNA itself are altered via genetic mutation. We will also highlight examples of small molecules that reprogram the enhancer landscape of leukemia cells in association with therapeutic benefit.

Potential Benefits of Annona muricata in Combating Cancer: A Review

The incidence of cancer is increasing each year, which generates concerns regarding the efficacy of the current treatment options. This has caused patients to seek alternatives to complement or to replace surgery, chemotherapy and radiotherapy. Annona muricata and other plants have been shown to have promising compounds that can be utilised in the treatment of cancer. Native to the tropical and subtropical parts of the world, A. muricata plant extracts contain compounds that are particularly effective against cancer cells. In light of increasing concerns regarding the limitations of cancer treatment in hospitals, this review attempts to highlight the benefits of A. muricata and its potential to be integrated as one of the treatment options against cancer.

Glycosylphosphatidylinositol (GPI) anchored protein deficiency serves as a reliable reporter of Pig-a gene Mutation: Support from an in vitro assay based on L5178Y/Tk+/- cells and the CD90.2 antigen

Lack of cell surface glycosylphosphatidylinositol (GPI)-anchored protein(s) has been used as a reporter of Pig-a gene mutation in several model systems. As an extension of this work, our laboratory initiated development of an in vitro mutation assay based on the flow cytometric assessment of CD90.2 expression on the cell surface of the mouse lymphoma cell line L5178Y/Tk^+/- . Cells were exposed to mutagenic and nonmutagenic compounds for 24 hr followed by washout and incubation for an additional 7 days. Following this mutant manifestation time, cells were labeled with fluorescent antibodies against CD90.2 and CD45 antigens. These reagents indicated the presence of GPI-anchored proteins and general cell surface membrane receptor integrity, respectively. Instrument set-up was aided by parallel processing of a GPI anchor-deficient subclone. Results show that the mutagens reproducibly caused increased frequencies of mutant phenotype cells, while the nonmutagens did not. Further modifications to the method, including application of a viability dye and an isotype control for instrument set-up, were investigated. As a means to verify that the GPI-anchored protein-negative phenotype reflects bona fide Pig-a gene mutation, sequencing was performed on 38 CD90.2-negative L5178Y/Tk^+/- clones derived from cultures treated with ethyl methanesulfonate. All clones were found to have mutation(s) within the Pig-a gene. The continued investigation of L5178Y/Tk^+/- cells, CD90.2 labeling, and flow cytometric analysis as the basis of an in vitro mutation assay is clearly supported by this work. These data also provide evidence of the reliability of using GPI anchor-deficiency as a valid reporter of Pig-a gene mutation. Environ. Mol. Mutagen. 59:18-29, 2018. © 2017 Wiley Periodicals, Inc.

Low Grade Lymphoma Mimicking Metastatic Urothelial Carcinoma: When Do We Need Further Histologic Staging?

Introduction. Patients with urothelial carcinoma of the bladder often present with metastases to regional lymph nodes, with lymphadenopathy on physical examination or radiographic imaging. Case Presentation. We present the case of a 73-year-old Caucasian man with presumed metastatic urothelial carcinoma of the bladder to regional pelvic and retroperitoneal lymph nodes. He underwent systemic chemotherapy for treatment of urothelial carcinoma and was discovered on restaging to have findings suggestive of disease progression but ultimately was found to have a concurrent secondary malignancy. Conclusion. Our case suggests that in patients with urothelial carcinoma, the concurrent presentation of regional lymphadenopathy may not be metastatic urothelial carcinoma and may warrant further investigation.

An oxovanadium(IV) complex protects murine bone marrow cells against cisplatin-induced myelotoxicity and DNA damage

Cisplatin (CDDP) is one of the first-line anticancer drugs that has gained widespread use against various forms of human malignancies. But, the therapeutic outcome of CDDP therapy is limited due to its adverse effects including myelotoxicity and DNA damage which may lead to the subsequent risk of developing secondary cancer. Hence, in search of a suitable cytoprotectant, this study investigated the probable protective efficacy of an oxovanadium(IV) complex, namely oxovanadium(IV)-L-cysteine methyl ester complex (VC-IV) against CDDP-induced myelosuppression and genotoxic damage in the bone marrow cells of Swiss albino mice. CDDP was administered intraperitoneally (5 mg/kg b.w.) and VC-IV was administered orally (1 mg/kg b.w.) in concomitant and 7 d pretreatment schedule. Treatment with VC-IV in CDDP-treated mice significantly (p < 0.01) enhanced bone marrow cell proliferation and inhibited cell death in the bone marrow niche indicating improvement of CDDP-induced myelotoxicity. The organovanadium compound also significantly (p < 0.01) reduced the percentage of chromosomal aberrations, the frequency of micronuclei formation, and the extent of DNA damage. The observed chemoprotective effect of VC-IV was attributed to its anti-oxidant efficacy which significantly (p < 0.01) attenuated CDDP-induced generation of free radicals, and restored (p < 0.01) the levels of oxidized and reduced glutathione. Hence, VC-IV may serve as a promising candidate for future development to decrease the deleterious effects of CDDP in the bone marrow cells of cancer patients and associated secondary complications.

Evaluation of single-dose RBC Pig-a and PIGRET assays in detecting the mutagenicity of thiotepa in rats

The Pig-a assay, which uses reticulocytes (PIGRET assay) as target cells, is anticipated to detect mutagenicity at earlier time points than the RBC Pig-a assay, which uses all red blood cells as target cells. As part of a collaborative study conducted by the Mammalian Mutagenicity Study (MMS) Group, we evaluated the PIGRET and RBC Pig-a assays to detect Pig-a gene mutations induced by the carcinogen thiotepa. A single dose of thiotepa at 7.5, 15, and 30mg/kg was administered to 8-week-old male Sprague-Dawley rats by oral gavage. PIGRET and RBC Pig-a assays were performed using peripheral blood collected from rats 7, 14, and 28days after thiotepa administration (Day 0 as the day of administration), and the resulting Pig-a mutant frequencies (MFs) were compared. Increased Pig-a MF was observed from Day 7 onwards using the PIGRET assay. Pig-a MF remained fairly constant thereafter until Day 28 in the 30mg/kg group, whereas it peaked on Day 14 in the 7.5 and 15mg/kg groups. Using the RBC Pig-a assay, on the other hand, no significant increase in MF was observed at any of the dosages on Days 7, 14, or 28. These findings show that Pig-a gene mutations following a single dose of thiotepa were detected using the PIGRET assay but not the RBC Pig-a assay, which suggests that PIGRET assay is more suitable than RBC Pig-a assay for evaluating the in vivo mutagenicity by a single dose.

Complete Remission of Acute Myeloid Leukemia following Cisplatin Based Concurrent Therapy with Radiation for Squamous Cell Laryngeal Cancer

Acute myeloid leukemia (AML) is a myeloid disorder with several established treatment regimens depending on patient and leukemic factors. Cisplatin is known to have strong leukemogenic potential and is rarely used even as salvage therapy in relapsed or refractory AML. We present a patient simultaneously diagnosed with AML and squamous cell carcinoma of the larynx, who was found to be in complete remission from AML following treatment with cisplatin based chemoradiotherapy for his laryngeal cancer.

Assessment of in vivo and in vitro genotoxicity of glibenclamide in eukaryotic cells

Glibenclamide is an oral hypoglycemic drug commonly prescribed for the treatment of type 2 diabetes mellitus, whose anti-tumor activity has been recently described in several human cancer cells. The mutagenic potential of such an antidiabetic drug and its recombinogenic activity in eukaryotic cells were evaluated, the latter for the first time. The mutagenic potential of glibenclamide in therapeutically plasma (0.6 μM) and higher concentrations (10 μM, 100 μM, 240 μM and 480 μM) was assessed by the in vitro mammalian cell micronucleus test in human lymphocytes. Since the loss of heterozygosity arising from allelic recombination is an important biologically significant consequence of oxidative damage, the glibenclamide recombinogenic activity at 1 μM, 10 μM and 100 μM concentrations was evaluated by the in vivo homozygotization assay. Glibenclamide failed to alter the frequency of micronuclei between 0.6 μM and 480 μM concentrations and the cytokinesis block proliferation index between 0.6 μM and 240 μM concentrations. On the other hand, glibenclamide changed the cell-proliferation kinetics when used at 480 μM. In the homozygotization assay, the homozygotization indices for the analyzed markers were lower than 2.0 and demonstrated the lack of recombinogenic activity of glibenclamide. Data in the current study demonstrate that glibenclamide, in current experimental conditions, is devoid of significant genotoxic effects. This fact encourages further investigations on the use of this antidiabetic agent as a chemotherapeutic drug.