Renal tuberculosis in an imatinib-treated chronic myeloid leukemia / Tuberculose renal em paciente com leucemia mieloide crônica tratado com imatinibe

ABSTRACT Imatinib, which inhibits tyrosine kinase activity of Bcr-Abl protein, is a standard form of treatment for chronic myeloid leukemia (CML). Through its immunomodulatory effect it affects T cell function in a number of ways. It inhibits antigen-induced T cell activation and proliferation. Antigen-specific T-cells and macrophages are vital for protection against Mycobacterium tuberculosis. Here we present a case of renal tuberculosis associated with imatinib therapy in the maintenance phase of CML. With granulomatous interstitial nephritis and positive tubercular DNA on renal biopsy, the condition was successfully treated with anti-tubercular therapy. This case provides support to the hypothesis that imatinib therapy in CML increases the susceptibility to tuberculosis and strict vigilance is required to enable its early detection and treatment.

RESUMO O imatinibe, um inibidor da atividade da tirosina-quinase da proteína BCR-ABL, faz parte do padrão de tratamento para leucemia mieloide crônica (LMC). Por conta de seu efeito imunomodulador, o imatinibe afeta a função dos linfócitos T de várias maneiras ao inibir a sua ativação e proliferação induzidas por antígenos. Linfócitos T e macrófagos antígeno-específicos são vitais para a proteção contra o Mycobacterium tuberculosis. O presente artigo relata um caso de tuberculose renal associada a terapia com imatinibe na fase de manutenção da LMC. Com nefrite intersticial granulomatosa e positividade para DNA de M. tuberculosis na biópsia renal, o paciente foi tratado com sucesso com terapia antituberculínica. O presente caso corrobora a hipótese de que a terapia com imatinibe na LMC aumenta a suscetibilidade à tuberculose, exigindo vigilância rigorosa para permitir sua detecção e tratamento precoces.

Aspectos clínicos, laboratoriais e tratamento da leucemia mieloide crônica em cão: relato de caso / Clinical aspects, hematological changes and treatments of chronic myeloid leukemia in dog: case report

O objetivo deste relato é apresentar o caso clínico de uma cadela, sem raça definida, com cinco anos de idade, diagnosticada com leucemia mieloide crônica (LMC). As leucemias são neoplasias malignas que se originam de células precursoras da medula óssea e as consequências podem ser trombocitopenia, anemia, leucocitose persistente e presença de células neoplásicas no sangue. O tratamento de escolha envolve o uso de inibidores de tirosina quinase, porém este não pode ser usado neste caso. Dessa forma a cadela recebeu diferentes protocolos quimioterápicos que incluíram inicialmente hidroxiureia, citarabina, doxorrubicina e prednisona. Devido a remissão parcial dos sinais clínicos e a resposta terapêutica pouco duradoura a essas medicações o protocolo foi alterado para quimioterapia metronômica com clorambucil. O uso desses quimioterápicos não foram eficazes em reduzir a leucocitose e controlar a anemia e trombocitopenia da paciente, devido a ocorrência do surgimento de células imaturas no sangue e resistência aos quimioterápicos. Na ausência da crise e da possibilidade do uso dos inibidores de tirosina quinase, a hidroxiureia permanece sendo o quimioterápico de eleição. O animal apresentou sobrevida de 210 dias, devido a leucocitose e anemia severas pouco responsivas ao protocolo terapêutico utilizado e o surgimento no hemograma de precursores neutrofilicos que ocorreu 46 dias após ao início do tratamento com hidroxiureia.

The aim of this report is to present the clinical case of a five-year-old mixed breed female dog diagnosed with chronic myeloid leukemia (CML). Leukemias are malignant neoplasms that originate from bone marrow precursor cells and the consequences can be thrombocytopenia, anemia, persistent leukocytosis and the presence of neoplastic cells in the blood. The treatment of choice involves the use of tyrosine kinase inhibitors, but it cannot be used in this case. Thus, the dog received different chemotherapy protocols that initially included hydroxyurea, cytarabine, doxorubicin and prednisone. Due to the partial remission of clinical signs and the short-term therapeutic response to these medications, the protocol was changed to metronomic chemotherapy with chlorambucil. The use of these chemotherapeutic agents was not effective in reducing leukocytosis and controlling the patient's anemia and thrombocytopenia, due to the occurrence of immature cells in the blood and resistance to chemotherapeutic agents. In the absence of the crisis and the possibility of using tyrosine kinase inhibitors, hydroxyurea remains the chemotherapy of choice. The animal had a 210-day survival, due to severe leukocytosis and anemia, which were not responsive to the therapeutic protocol used and the appearance in the blood count of neutrophilic precursors that occurred 46 days after the beginning of hydroxyurea treatment.

IL-17A/lL-17RA reduces cisplatin sensitivity of ovarian cancer SKOV3 cells by regulating autophagy / 南方医科大学学报

OBJECTIVE@#To investigate the effect of interleukin-17A (IL-17A) on chemosensitivity of ovarian cancer cells to cisplatin (DDP) and explore the mechanism in light of autophagy regulation.@*METHODS@#Ovarian cancer SKOV3 cells cultured @*RESULTS@#DDP increased the expression of IL-17RA in ovarian cancer SKOV3 cells. Treatment with IL-17A significantly reduced the susceptibility of SKOV3 cells to cisplatin-induced apoptosis (@*CONCLUSIONS@#IL-17A/IL-17RA can decrease chemosensitivity of SKOV3 cells to DDP by upregulating DDP-induced autophagy.

MicroRNA-340-5p modulates cisplatin resistance by targeting LPAATβ in osteosarcoma

MicroRNAs (miRNAs) play an important role in drug resistance and modulate the efficiency of chemotherapy. A recent study indicated that miR-340 functions as a tumor suppressor in various types of cancer. However, the role of miR-340 in chemotherapy has not been reported yet. In this study, we found that miR-340 enhanced cisplatin (CDDP)-induced cell death. Induction of miR-340-5p expression decreased the IC50 of CDDP and increased the apoptosis of CDDP-resistant MG-63 and Saos-2 cells. Moreover, miR-340-5p decreased the accumulation of MRP1 and MDR1. We further explored the mechanism underlying the promoting effects of miR-340-5p on CDDP-induced cell death. We identified a potential target of miR-340 in the 3′ untranslated region of lysophosphatidic acid acyltransferase (LPAATβ) using the online program Targetscan (http://www.microrna.org). Luciferase reporter assays showed that miR-340 binds to the 3′UTR of LPAATβ. Enforced expression of miR-340-5p decreased the accumulation of LPAATβ in both MG-63 and Saos-2 cells. Silencing LPAATβ decreased the IC50 of CDDP and increased the apoptosis of CDDP-resistant MG-63 and Saos-2 cells, which is consistent with the effect of miR-340-5p on CDDP-induced cell death. Moreover, induced expression of LPAATβ compromised the effects of miR-340-5p on CDDP-induced cell death and accumulation of MRP1 and MDR1. Taken together, our data indicated that miR-340-5p enhanced the sensitivity to CDDP by targeting LPAATβ.

EGF Induced RET Inhibitor Resistance in CCDC6-RET Lung Cancer Cells

PURPOSE: Rearrangement of the proto-oncogene rearranged during transfection (RET) has been newly identified potential driver mutation in lung adenocarcinoma. Clinically available tyrosine kinase inhibitors (TKIs) target RET kinase activity, which suggests that patients with RET fusion genes may be treatable with a kinase inhibitor. Nevertheless, the mechanisms of resistance to these agents remain largely unknown. Thus, the present study aimed to determine whether epidermal growth factor (EGF) and hepatocyte growth factor (HGF) trigger RET inhibitor resistance in LC-2/ad cells with CCDC6-RET fusion genes. MATERIALS AND METHODS: The effects of EGF and HGF on the susceptibility of a CCDC6-RET lung cancer cell line to RET inhibitors (sunitinib, E7080, vandetanib, and sorafenib) were examined. RESULTS: CCDC6-RET lung cancer cells were highly sensitive to RET inhibitors. EGF activated epidermal growth factor receptor (EGFR) and triggered resistance to sunitinib, E7080, vandetanib, and sorafenib by transducing bypass survival signaling through ERK and AKT. Reversible EGFR-TKI (gefitinib) resensitized cancer cells to RET inhibitors, even in the presence of EGF. Endothelial cells, which are known to produce EGF, decreased the sensitivity of CCDC6-RET lung cancer cells to RET inhibitors, an effect that was inhibited by EGFR small interfering RNA (siRNA), anti-EGFR antibody (cetuximab), and EGFR-TKI (Iressa). HGF had relatively little effect on the sensitivity to RET inhibitors. CONCLUSION: EGF could trigger resistance to RET inhibition in CCDC6-RET lung cancer cells, and endothelial cells may confer resistance to RET inhibitors by EGF. E7080 and other RET inhibitors may provide therapeutic benefits in the treatment of RET-positive lung cancer patients.

Use of deferasirox, an iron chelator, to overcome imatinib resistance of chronic myeloid leukemia cells

BACKGROUND/AIMS: The treatment of chronic myeloid leukemia (CML) has achieved impressive success since the development of the Bcr-Abl tyrosine kinase inhibitor, imatinib mesylate. Nevertheless, resistance to imatinib has been observed, and a substantial number of patients need alternative treatment strategies. METHODS: We have evaluated the effects of deferasirox, an orally active iron chelator, and imatinib on K562 and KU812 human CML cell lines. Imatinib-resistant CML cell lines were created by exposing cells to gradually increasing concentrations of imatinib. RESULTS: Co-treatment of cells with deferasirox and imatinib induced a synergistic dose-dependent inhibition of proliferation of both CML cell lines. Cell cycle analysis showed an accumulation of cells in the subG1 phase. Western blot analysis of apoptotic proteins showed that co-treatment with deferasirox and imatinib induced an increased expression of apoptotic proteins. These tendencies were clearly identified in imatinib-resistant CML cell lines. The results also showed that co-treatment with deferasirox and imatinib reduced the expression of BcrAbl, phosphorylated Bcr-Abl, nuclear factor-kappaB (NF-kappaB) and beta-catenin. CONCLUSIONS: We observed synergistic effects of deferasirox and imatinib on both imatinib-resistant and imatinib-sensitive cell lines. These effects were due to induction of apoptosis and cell cycle arrest by down-regulated expression of NF-kappaB and beta-catenin levels. Based on these results, we suggest that a combination treatment of deferasirox and imatinib could be considered as an alternative treatment option for imatinib-resistant CML.

Silencing of ABCG2 by MicroRNA-3163 Inhibits Multidrug Resistance in Retinoblastoma Cancer Stem Cells

To investigate the function and regulation mechanism of ATP-binding cassette, subfamily G, member 2 (ABCG2) in retinoblastoma cancer stem cells (RCSCs), a long-term culture of RCSCs from WERI-Rb1 cell line was successfully established based on the high expression level of ABCG2 on the surface of RCSCs. To further explore the molecular mechanism of ABCG2 on RCSCs, a microRNA that specifically targets ABCG2 was predicted. Subsequently, miR-3163 was selected and confirmed as the ABCG2-regulating microRNA. Overexpression of miR-3163 led to a significant decrease in ABCG2 expression. Additionally, ABCG2 loss-of-function induced anti-proliferation and apoptosis-promoting functions in RCSCs, and multidrug resistance to cisplatin, carboplatin, vincristine, doxorubicin, and etoposide was greatly improved in these cells. Our data suggest that miR-3163 has a significant impact on ABCG2 expression and can influence proliferation, apoptosis, and drug resistance in RCSCs. This work may provide new therapeutic targets for retinoblastoma.

Tumor size and prognosis in patients with Wilms tumor / Tamanho tumoral e prognóstico em pacientes portadores de tumor de Wilms

OBJECTIVE: Investigate the relationship of the tumor volume after preoperative chemotherapy (TVAPQ) and before preoperative chemotherapy (TVBPQ) with overall survival at two and at five years, and lifetime. METHODS: Our sample consisted of consecutive patients evaluated in the period from 1989 to 2009 in an Onco-Hematology Service. Clinical, histological and volumetric data were collected from the medical records. For analysis, chi-square, Kaplan-Meier, log-rank and Cox regression tests were used. RESULTS: The sample consisted of 32 patients, 53.1% were male with a median age at diagnosis of 43 months. There was a significant association between TVAPQ>500mL and the difference between the TVBPQ and TVAPQ (p=0.015) and histologic types of risk (p=0.008). It was also verified an association between the difference between the TVBPQ and TVAPQ and the predominant stromal tumor (p=0.037). When assessing the TVAPQ of all patients, without a cutoff, there was an association of the variable with lifetime (p=0.013), i.e., for each increase of 10mL in TVAPQ there was an average increase of 2% in the risk of death. CONCLUSIONS: Although our results indicate that the TVAPQ could be considered alone as a predictor of poor prognosis regardless of the cutoff suggested in the literature, more studies are needed to replace the histology and staging by tumor size as best prognostic variable. .

OBJETIVO: Investigar a relação entre o volume do tumor após a quimioterapia pré-operatória (VTPOS) e antes da quimioterapia pré-operatória (VTPRE) com sobrevida geral aos dois e cinco anos e tempo de vida. MÉTODOS: A amostra foi composta por pacientes consecutivos avaliados de 1989 a 2009, em um serviço de onco-hematologia. Os dados clínicos, histológicos e volumétricos foram coletados a partir dos registros médicos. Para análise, usaram-se os testes qui-quadrado, Kaplan-Meier, log-rank e regressão de Cox. RESULTADOS: A amostra foi composta de 32 pacientes, 53,1% do sexo masculino, com mediana de idade ao diagnóstico de 43 meses. Houve associação significativa entre VTPOS >500 mL e a diferença entre o VTPRE e VTPOS (p=0,015) e os tipos histológicos de risco (p=0,008). Verificou-se também uma associação entre a diferença entre o VTPRE e VTPOS e o tumor de predomínio estromal (p=0,037). Quando se avaliou o VTPOS de todos os pacientes, sem um ponto de corte definido, observou-se associação dessa variável com o tempo de vida (p=0,013), isto é, para cada aumento de 10 mL no VTPOS houve um aumento médio de 2% no risco de morte. CONCLUSÕES: Embora os resultados indiquem que o VTPOS poderia ser considerado um preditor isolado de mau prognóstico, independentemente do ponto de corte sugerido na literatura, mais estudos são necessários para substituir a histologia e estadiamento pelo tamanho do tumor como melhor variável prognóstica. .

Imatinib mesylate as first‑line therapy in patients with chronic myeloid leukemia in accelerated phase and blast phase: A retrospective analysis.

INTRODUCTION: Imatinib is a bcr‑abl tyrosine kinase inhibitor which has revolutionized the treatment for chronic myeloid leukemia (CML). Even though there is much data on CML chronic phase, there is limited data on imatinib‑naïve advanced phase CML. MATERIALS AND METHODS: We retrospectively analysed 90 patients with advanced phase CML (accelerated phase [AP]: 51 and blast crisis [BC]: 39), patients who received imatinib as frontline therapy. RESULTS: The median age of presentation in CML‑AP and CML‑BC were 32 years (12‑61) and 39 years (8‑59), respectively. Imatinib at 600 mg/day was initiated within 2 weeks of diagnosis. Median time to complete hematological response in both CML‑AP and CML‑BC was 3 months (CML‑AP: 1‑9 months and CML‑BC: 1‑14 months). At 6 months 30 (59%) CML‑AP and 15 (38%) CML‑BC patients achieved major cytogenetic response (MCyR), of them 24 (47%) and 10 (25.6%) being the complete cytogenetic response, respectively. At a median follow‑up of 41 months, the median overall survival in CML‑AP was 61 months, but in CML‑BC it was 14 months. The median progression‑free survival and event‑free survival were 30 months and 23 months in CML‑AP and 14 and 12 months in CML‑BC, respectively. On univariate analysis, performance status (PS), spleen size, and MCyR predicted survival in AP, whereas in BC, platelet count, PS, and early MCyR were predictive. Non‑hematologic and hematologic adverse events were observed in 80% and 60% of patients, respectively. Dose was reduced in 10% of patients for grade IV toxicity and interrupted in 30% for grade III toxicity. CONCLUSION: Front‑line imatinib is an option in advanced phases of CML especially in CML‑AP in low‑resource countries, where stem cell transplantation and alternate TKIs are not available.

Celecoxib decreases growth and angiogenesis and promotes apoptosis in a tumor cell line resistant to chemotherapy

BACKGROUND: During the last few years it has been shown in several laboratories that Celecoxib (Cx), a non-steroidal anti-inflammatory agent (NSAID) normally used for pain and arthritis, mediates antitumor and antiangiogenic effects. However, the effects of this drug on a tumor cell line resistant to chemotherapeutical drugs used in cancer have not been described. Herein we evaluate the angiogenic and antitumor effects of Cx in the development of a drug-resistant mammary adenocarcinoma tumor (TA3-MTXR). RESULTS: Cx reduces angiogenesis in the chick embryonic chorioallantoic membrane assay (CAM), inhibits the growth and microvascular density of the murine TA3-MTXR tumor, reduces microvascular density of tumor metastases, promotes apoptosis and reduces vascular endothelial growth factor (VEGF) production and cell proliferation in the tumor. CONCLUSION: The antiangiogenic and antitumor Cx effects correlate with its activity on other tumor cell lines, suggesting that Prostaglandins (PGs) and VEGF production are involved. These results open the possibility of using Celecoxib combined with other experimental therapies, ideally aiming to get synergic effects.

2,3,7,8-Tetrachlorodibenzo-P-Dioxin Induced Cell-Specific Drug Transporters With Acquired Cisplatin Resistance in Cisplatin Sensitive Cancer Cells

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can induce drug transporter genes such as the ATP-binding cassette G member 2 (ABCG2), which contributes to multidrug resistance. We investigated the effect of TCDD pretreatment on drug transporters induction from cancer cells of various origins. Cell viabilities after treatment of cisplatin were measured to evaluate acquiring cisplatin resistance by TCDD. Acquring cisplatin resistance was found only in cisplatin senstivie cancer cells including gastric SNU601, colon LS180, brain CRT-MG and lymphoma Jurkat cells which showed a significant increase in cell viability after combined treatment with TCDD and cisplatin. High increase of ABCG2 gene expression was found in SNU601 and LS180 cells with a mild increase in the expression of the ABCC3, ABCC5,and SLC29A2 genes in SNU601 cells, and of major vault protein (MVP) in LS180 cells. The AhR inhibitor kaempferol suppressed the upregulation of ABCG2 expression and reversed the TCDD-induced increase in cell viability in LS180 cells. However, in CRT-MG cells, other transporter genes including ABCC1, ABCC5, ABCA3, ABCA2, ABCB4, ABCG1, and SLC29A1 were up-regulated. These findings suggested the acquiring cisplatin resistance by TCDD associated with cancer cell-type-specific induction of drug transporters.

2,3,7,8-Tetrachlorodibenzo-P-Dioxin Induced Cell-Specific Drug Transporters With Acquired Cisplatin Resistance in Cisplatin Sensitive Cancer Cells

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can induce drug transporter genes such as the ATP-binding cassette G member 2 (ABCG2), which contributes to multidrug resistance. We investigated the effect of TCDD pretreatment on drug transporters induction from cancer cells of various origins. Cell viabilities after treatment of cisplatin were measured to evaluate acquiring cisplatin resistance by TCDD. Acquring cisplatin resistance was found only in cisplatin senstivie cancer cells including gastric SNU601, colon LS180, brain CRT-MG and lymphoma Jurkat cells which showed a significant increase in cell viability after combined treatment with TCDD and cisplatin. High increase of ABCG2 gene expression was found in SNU601 and LS180 cells with a mild increase in the expression of the ABCC3, ABCC5,and SLC29A2 genes in SNU601 cells, and of major vault protein (MVP) in LS180 cells. The AhR inhibitor kaempferol suppressed the upregulation of ABCG2 expression and reversed the TCDD-induced increase in cell viability in LS180 cells. However, in CRT-MG cells, other transporter genes including ABCC1, ABCC5, ABCA3, ABCA2, ABCB4, ABCG1, and SLC29A1 were up-regulated. These findings suggested the acquiring cisplatin resistance by TCDD associated with cancer cell-type-specific induction of drug transporters.

Early responses of the STAT3 pathway to platinum drugs are associated with cisplatin resistance in epithelial ovarian cancer

Cisplatin resistance remains one of the major obstacles when treating epithelial ovarian cancer. Because oxaliplatin and nedaplatin are effective against cisplatin-resistant ovarian cancer in clinical trials and signal transducer and activator of transcription 3 (STAT3) is associated with cisplatin resistance, we investigated whether overcoming cisplatin resistance by oxaliplatin and nedaplatin was associated with the STAT3 pathway in ovarian cancer. Alamar blue, clonogenic, and wound healing assays, and Western blot analysis were used to compare the effects of platinum drugs in SKOV-3 cells. At an equitoxic dose, oxaliplatin and nedaplatin exhibited similar inhibitory effects on colony-forming ability and greater inhibition on cell motility than cisplatin in ovarian cancer. Early in the time course of drug administration, cisplatin increased the expression of pSTAT3 (Tyr705), STAT3α, VEGF, survivin, and Bcl-XL, while oxaliplatin and nedaplatin exhibited the opposite effects, and upregulated pSTAT3 (Ser727) and STAT3β. The STAT3 pathway responded early to platinum drugs associated with cisplatin resistance in epithelial ovarian cancer and provided a rationale for new therapeutic strategies to reverse cisplatin resistance.

Effect of curcumin on human colon cancer multidrug resistance in vitro and in vivo

OBJECTIVE: To determine whether curcumin reverses the multidrug resistance of human colon cancer cells in vitro and in vivo. METHODS: In a vincristine-resistant cell line of human colon cancer, the cell viability of curcumin-treated cells was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Rhodamine123 efflux was evaluated to detect P-glycoprotein transporter activity, and expression of the multidrug resistance protein 1 and survivin genes was analyzed by reverse transcription polymerase chain reaction and western blotting. In addition, xenograft mouse tumors were grown and treated with curcumin. The morphology of the xenografts was investigated by hematoxylin-eosin staining. The in vivo expression of the multidrug resistance gene and P-glycoprotein and survivin genes and proteins was observed using reverse transcription-polymerase chain reaction and western blotting, respectively. RESULTS: Curcumin was not obviously toxic to the vincristine-resistant human colon cancer cells at concentrations less than 25 μM, but the growth of cells was significantly inhibited. At concentrations greater than 25 μM, curcumin was toxic in a concentration-dependent manner. The sensitivity of cells to vincristine, cisplatin, fluorouracil, and hydroxycamptothecin was enhanced, intracellular Rhodamine123 accumulation was increased (p<0.05), and the expression of the multidrug resistance gene and P-glycoprotein were significantly suppressed (p<0.05). The combination of curcumin and vincristine significantly inhibited xenograft growth. The expression of the multidrug resistance protein 1 and survivin genes was significantly reduced in xenografts of curcumin-treated mice and mice treated with both curcumin and vincristine relative to control mice. CONCLUSION: Curcumin has strong reversal effects on the multidrug resistance of human colon carcinoma in vitro and in vivo. .

Expression of Heat Shock Protein 70 Modulates the Chemoresponsiveness of Pancreatic Cancer

BACKGROUND/AIMS: Heat shock protein (HSP) 70 is constitutively overexpressed in pancreatic cancer cells (PCCs) and appears to confer protection against chemotherapeutics. We investigated whether modulating HSP 70 increases chemoresponsiveness to gemcitabine in PCCs. METHODS: Varying concentrations of quercetin and gemcitabine, either alone or in combination, were added to PCCs (Panc-1 and MiaPaCa-2). MTT assay was performed to analyze cell viability. HSP 70 expression was assessed by Western blot analysis. Apoptosis was determined by measuring caspase-3 activity. Western blot for the LC3-II protein detected the presence of autophagy. RESULTS: HSP 70 levels were not affected by the incubation of Panc-1 and MiaPaCa-2 cells with gemcitabine, whereas with quercetin, the levels were reduced in both cell lines. The viability of both Panc-1 and MiaPaCa-2 cells significantly decreased with gemcitabine treatment but not with quercetin. A combination of gemcitabine and quercetin decreased the viability of both cell lines in a dose-dependent manner, which was more pronounced than gemcitabine treatment alone. Treatment with either gemcitabine or quercetin augmented caspase-3 activity in both cell lines, and a combination of these compounds further potentiated caspase-3 activity. LC3-II protein expression was negligible with gemcitabine treatment but marked with quercetin. The addition of gemcitabine to quercetin did not potentiate LC3-II protein expression. CONCLUSIONS: Modulation of HSP 70 expression with quercetin enhanced the chemoresponsiveness of PCCs to gemcitabine. The mechanism of cell death was both apoptosis and autophagy.

Adenovirus adenine nucleotide translocator-2 shRNA effectively induces apoptosis and enhances chemosensitivity by the down-regulation of ABCG2 in breast cancer stem-like cells

Cancer stem cells (CSCs) are resistant to chemo- and radio-therapy, and can survive to regenerate new tumors. This is an important reason why various anti-cancer therapies often fail to completely control tumors, although they kill and eliminate the bulk of cancer cells. In this study, we determined whether or not adenine nucleotide translocator-2 (ANT2) suppression could also be effective in inducing cell death of breast cancer stem-like cells. A sub-population (SP; CD44+/CD24-) of breast cancer cells has been reported to have stem/progenitor cell properties. We utilized the adeno-ANT2 shRNA virus to inhibit ANT2 expression and then observed the treatment effect in a SP of breast cancer cell line. In this study, MCF7, MDA-MB-231 cells, and breast epithelial cells (MCF10A) mesenchymally-transdifferentiated through E-cadherin knockdown were used. ANT2 expression was high in both stem-like cells and non-stem-like cells of MCF7 and MDA-MB-231 cells, and was induced and up-regulated by mesenchymal transdifferentiation in MCF10A cells (MCF10AEMT). Knockdown of ANT2 by adeno-shRNA virus efficiently induced apoptotic cell death in the stem-like cells of MCF7 and MDA-MB-231 cells, and MCF10AEMT. Stem-like cells of MCF7 and MDA-MB-231, and MCF10AEMT cells exhibited increased drug (doxorubicin) resistance, and expressed a multi-drug resistant related molecule, ABCG2, at a high level. Adeno-ANT2 shRNA virus markedly sensitized the stem-like cells of MCF7 and MDA-MB-231, and the MCF10AEMT cells to doxorubicin, which was accompanied by down-regulation of ABCG2. Our results suggest that ANT2 suppression by adeno-shRNA virus is an effective strategy to induce cell death and increase the chemosensitivity of stem-like cells in breast cancer.

The hypothesis of an effective strategy for resistance of hepatocellular carcinoma to therapy-autophagy / La hipótesis de una estrategia efectiva para la resistencia del carcinoma hepatocelular a la terapia autofágica

Hepatocellular carcinoma (HCC) is one of the most common malignant tumours and its five-year survival rate remains low. Autophagy is a catabolic process conserved among all eukaryotes ranging from yeast to mammals. Recently, many studies show that tumour cells can utilize autophagy as a cellular defence mechanism when facing metabolic stress. Thus, we hypothesize that autophagy may play an important role in the resistance of hepatocellular carcinomas to therapy. Although the exact role of autophagy on tumour cells is still complex and further studies are needed to prove the impact of autophagy on HCC, it suggests that autophagy may be a new therapeutic target for the resistance to therapy of HCC.

El carcinoma hepatocelular (CHC) es uno de los tumores malignos más comunes, y su tasa de super-vivencia a los cinco años sigue siendo baja. La autofagia es un proceso catabólico conservado en todos los eucariotas, que abarca desde las levaduras hasta los mamíferos. Recientemente, numerosos estudios han demostrado que las células tumorales pueden utilizar la autofagia como un mecanismo celular de defensa frente al estrés metabólico. De este modo, sostenemos la hipótesis de que la autofagia puede desempeñar un papel importante en la resistencia de los carcinomas hepatocelulares a la terapia. Aunque el papel exacto de la autofagia en las celulares tumorales sigue siendo complejo, y se requieren más estudios a fin de probar el impacto de la autofagia en el CHC, hay indicios de que la autofagia puede ser un nuevo objetivo terapéutico para la resistencia a la terapia del CHC.

Betamethasone inhibits tumor development, microvessel density and prolongs survival in mice with a multiresistant adenocarcinoma TA3

Tumor resistance to traditional cancer treatments poses an important challenge to modern science. Thus, angiogenesis inhibition is an important emerging cancer treatment. Many drugs are tested and corticosteroids have shown interesting results. Herein we investigate the effect on microvessel density, survival time and tumoral volume of mice with TA3-MTX-R tumors. Twenty six mice were inoculated with lxlO6 tumor cells, 4-5 days after injection, six mice were injected with PBS (group A) and twenty mice were treated with p-met (group B). All animals from Group A died on day 22. Group B was divided into Bl (treated discontinued) and B2 (treated daily) and observed until day 88. All mice were processed for histo-immunohistochemical analysis and the blood vessels were counted. A decrease in microvessel density and tumoral volume and longer survival times were observed in the treated group. We propose that the antiangiogenic p-met effect explains, at least partially, its tumor inhibitory properties. As an important perspective, we will experimentally combine these strategies with those recently described by us with regard to the important antiangiogenic-antitumor effects of Trypanosoma cruzi calreticulin. Since the molecular targets of these strategies are most likely different, additive or synergic effects are envisaged.

Toxicity mechanisms of onion (Allium cepa) extracts and compounds in multidrug resistant erythroleukemic cell line

Onion (Allium cepa) is being studied as a potential anticancer agent, but little is known regarding its effect in multidrug resistance (MDR) cells. In this work, the cytotoxicity of crude onion extract (OE) and fractioned extract (aqueous, methanolic and ethyl acetate), as well as some onion compounds (quercetin and propyl disulfide) were evaluated in Lucena MDR human erythroleukemic and its K562 parental cell line. The capacity of OE to induce apoptosis and/or necrosis in these cells, the possible participation of oxidative stress and DNA damage were also assessed. Similar sensitivities were obtained for both tumoral cells, however only OE caused significant effects in the cells. In K562 cells, a significant increase of apoptosis was verified while the Lucena cells experienced a significant increase of necrosis. An antioxidant capacity was verified for OE discarding oxidative damage. However, OE provoked similar significant DNA damage in both cell lines. Thus, the OE capacity to overcome the MDR phenotype suggests anti-MDR action of OE.

Enhancement of parthenolide-induced apoptosis by a PKC-alpha inhibition through heme oxygenase-1 blockage in cholangiocarcinoma cells

Cholangiocarcinoma (CC) is a chemoresistant intrahepatic bile duct carcinoma with a poor prognosis. The aims of this study were to identify molecular pathways that enhance sesquiterpene lactone parthenolide (PTL)-induced anticancer effects on CC cells. The effects of PTL on apoptosis and hemoxygenase-1 (HO-1) induction were examined in CC cell lines. The enhancement of PTL-mediated apoptosis by modulation of HO-1 expression and the mechanisms involved were also examined in an in vitro cell system. Low PTL concentrations (5 to 10 micrometer) led to Nrf2-dependent HO-1 induction, which attenuated the apoptogenic effect of PTL in Choi-CK and SCK cells. PTL-mediated apoptosis was enhanced by the protein kinase C-alpha inhibitor Ro317549 (Ro) through inhibition of expression and nuclear translocation of Nrf2, resulting in blockage of HO-1 expression. Finally, HO-1 silencing resulted in enhancement of apoptotic cell death in CC cells. The combination of PTL and Ro efficiently improved tumor growth inhibition compared to treatment with either agent alone in an in vivo subcutaneous tumor model. In conclusion, the modulation of HO-1 expression substantially improved the anticancer effect of PTL. The combination of PTL and Ro could prove to be a valuable chemotherapeutic strategy for CC.