Hepatocyte growth factor and inducible nitric oxide synthase are involved in multidrug resistance-induced angiogenesis in hepatocellular carcinoma cell lines.

Based on literature, it is possible to hypothesize that multidrug resistance (MDR) and angiogenic phenotypes are linked to each other in human liver cancer cells. Our goal is to assess whether MDR cells trigger angiogenesis and to study the possible molecular mechanisms involved. Conditioned medium from parental drug-sensitive P5 cells (P5-CM) and MDR-positive P1(0.5) cells [P1(0.5)-CM] stimulated human umbilical vein endothelial cells (HUVEC) survival, proliferation, migration, and microtubular structure formation, but P1(0.5)-CM had a significantly greater effect than P5-CM. Cell implants were done in the rabbit avascular cornea to measure angiogenesis in vivo: P1(0.5) cells induced an important neovascular response in rabbit cornea after 1 week, whereas P5 cells had no effect. P1(0.5) and P5 cells produced vascular endothelial growth factor, but only P1(0.5) secreted hepatocyte growth factor (HGF) into the medium, and small interfering RNA specific for MDR1 clearly reduced HGF production in P1(0.5) cells. The transcription factor Ets-1 and the HGF receptor c-Met were up-regulated in P1(0.5) cells and in HUVEC cultured in P1(0.5)-CM. Inducible nitric oxide synthase (iNOS) seemed to play a major role in the proangiogenic effect of P1(0.5), and its inhibition by 1400W blunted the capacity of P1(0.5) cells to stimulate HUVEC proliferation, migration, and Ets-1 expression. In conclusion, these data show that development of MDR and angiogenic phenotypes are linked to each other in MDR cells. HGF production, Ets-1 and c-Met up-regulation, and iNOS expression can be part of the molecular mechanisms that enhance the angiogenic activity of the MDR-positive hepatocellular carcinoma cell line.

The effect of Bcrp1 (Abcg2) on the in vivo pharmacokinetics and brain penetration of imatinib mesylate (Gleevec): implications for the use of breast cancer resistance protein and P-glycoprotein inhibitors to enable the brain penetration of imatinib in patients.

Imatinib mesylate (signal transduction inhibitor 571, Gleevec) is a potent and selective tyrosine kinase inhibitor, which was shown to effectively inhibit platelet-derived growth factor-induced glioblastoma cell growth preclinically. However, in patients, a limited penetration of imatinib into the brain has been reported. Imatinib is transported in vitro and in vivo by P-glycoprotein (P-gp; ABCB1), which thereby limits its distribution into the brain in mice. Previously, imatinib was shown to potently inhibit human breast cancer resistance protein (BCRP; ABCG2). Here, we show that imatinib is efficiently transported by mouse Bcrp1 in transfected Madin-Darby canine kidney strain II (MDCKII) monolayers. Furthermore, we show that the clearance of i.v. imatinib is significantly decreased 1.6-fold in Bcrp1 knockout mice compared with wild-type mice. At t = 2 hours, the brain penetration of i.v. imatinib was significantly 2.5-fold increased in Bcrp1 knockout mice compared with control mice. We tested the hypothesis that P-gp and BCRP inhibitors, such as elacridar and pantoprazole, improve the brain penetration of imatinib. Firstly, we showed in vitro that pantoprazole and elacridar inhibit the Bcrp1-mediated transport of imatinib in MDCKII-Bcrp1 cells. Secondly, we showed that co-administration of pantoprazole or elacridar significantly reduced the clearance of i.v. imatinib in wild-type mice by respectively 1.7-fold and 1.5-fold. Finally, in wild-type mice treated with pantoprazole or elacridar, the brain penetration of i.v. imatinib significantly increased 1.8-fold and 4.2-fold, respectively. Moreover, the brain penetration of p.o. imatinib increased 5.2-fold when pantoprazole was co-administered in wild-type mice. Our results suggest that co-administration of BCRP and P-gp inhibitors may improve delivery of imatinib to malignant gliomas.

Unusual gastric and pancreatic metastatic renal cell carcinoma presentation 10 years after surgery and immunotherapy: A case report and a review of literature.

Renal cell carcinoma (RCC) is the most common renal tumor, accounting for 2%-3% of all malignancies. Though RCC is known to spread hematogenously, isolated RCC metastasis to the stomach is a rare event. In this article, we describe the clinical course of a patient who developed a pancreatic recurrence of RCC and 1 year later a gastric recurrence of RCC treated 10 years ago with a resection and interleukin-2 (IL-2). Accumulating evidence indicates that metastatic involvement of the pancreas and stomach should be suspected in any patient with a history of RCC who presents with gastrointestinal symptoms even 10 years after RCC resection and immunotherapy.

An uncommon clinical presentation of retroperitoneal non-Hodgkin lymphoma successfully treated with chemotherapy: a case report.

We report the case of a patient affected by an extra-nodal non-Hodgkin lymphoma presenting as a unique, large retroperitoneal mass with an unusual clinical presentation mimicking gastric peptic or neoplastic disease. The patient was successfully treated with a first generation therapy, CHOP modified regimen (cyclophosphamide 600 mg/m2 intravenously on d 1, epirubicin 55 mg/m2 intravenously on d 1, vincristine 1.2 mg/m2 intravenously on d 1, prednisone 60 mg/m2 on d 1-5), and a complete response was achieved. The (18)F-fluorodeoxyglucose positron emission tomography was used to assess the therapy outcome. A brief review of literature is provided.

Survival and prognostic factors in patients with hepatocellular carcinoma treated by percutaneous ethanol injection: a 10-year experience.

The treatment of early and intermediate stage hepatocellular carcinoma (HCC) is still debated. Surgical treatments are considered to be the only curative procedures available, and only for a minority of patients. Percutaneous ethanol injection (PEI) is an established technique for the ablation of HCC nodules, and shows survival rates similar to those of resection. The efficacy of PEI in patients with biopsy-proven viral cirrhosis and small to intermediate inoperable HCC was evaluated. One hundred twenty-seven patients (85 men, 42 women, mean age 63 years, range 51 to 92 years, 115 hepatitis C virus-positive, 12 hepatitis B virus-positive) were enrolled between January 1993 and December 2002. They all underwent a standard PEI procedure and were prospectively followed-up. Overall median survival rate was 28 months (range six to 112 months). The following parameters were associated with a significantly longer survival: nodule diameter smaller than 30 mm (P=0.0480), the presence of a perinodular boundary (P=0.0008), serum alpha-fetoprotein less than 20 ng/mL (P=0.0104), a Child-Pugh A class score (P<0.0001) or a Cancer of the Liver Italian Program score of 0 (P<0.0001) and the presence or absence of small esophageal varices (P=0.013). The 19 patients with all these favourable characteristics showed an overall median survival of 61 months. An alpha-fetoprotein below 20 ng/mL was associated with significantly longer disease-free survival (P=0.0009). The Child-Pugh and Cancer of the Liver Italian Program scores were effective in predicting prognosis of these patients. In conclusion, PEI still represents a safe and economically sound treatment for HCC.

Molecularly targeted therapy: toxicity and quality of life considerations in advanced colorectal cancer.

Colorectal cancer (CRC) is the third most common malignancy and cause of death from cancer among adults worldwide. In recent years, the use of 5-fluorouracil-based regimens in combination with molecularly targeted agents has greatly expanded treatment options for patients with metastatic disease. With a more capillary use of this new class of agents comes the recognition of diverse adverse events related to disturbance of critical biological pathways involved in physiological functions. Proactive management and prevention of adverse events, with a focus on the necessary compromise between adverse events and tumor control, are often effective and allows for uninterrupted, full-dose therapy with targeted agents. Quality of life does not appear deteriorated, rather improved due to efficacy in prolonging wellness.

Mitochondrial expression and functional activity of breast cancer resistance protein in different multiple drug-resistant cell lines.

The multidrug resistance (MDR) phenotype is characterized by the overexpression of a few transport proteins at the plasma membrane level, one of which is the breast cancer resistance protein (BCRP). These proteins are expressed in excretory organs, in the placenta and blood-brain barrier, and are involved in the transport of drugs and endogenous compounds. Because some of these proteins are expressed in the mitochondria, this study was designed to determine whether BCRP is expressed at a mitochondrial level and to investigate its function in various MDR and parental drug-sensitive cell lines. By using Western blot analysis, immunofluorescence confocal and electron microscopy, flow cytometry analysis, and the BCRP (ABCG-2) small interfering RNA, these experiments showed that BCRP is expressed in the mitochondrial cristae, in which it is functionally active. Mitoxantrone accumulation was significantly reduced in mitochondria and in cells that overexpress BCRP, in comparison to parental drug-sensitive cells. The specific inhibitor of BCRP, fumitremorgin c, increased the accumulation of mitoxantrone significantly in comparison with basal conditions in both whole cells and in mitochondria of BCRP-overexpressing cell lines. In conclusion, this study shows that BCRP is overexpressed and functionally active in the mitochondria of MDR-positive cancer cell lines. However, its presence in the mitochondria of parental drug-sensitive cells suggests that BCRP can be involved in the physiology of cancer cells.

The effect of low pH on breast cancer resistance protein (ABCG2)-mediated transport of methotrexate, 7-hydroxymethotrexate, methotrexate diglutamate, folic acid, mitoxantrone, topotecan, and resveratrol in in vitro drug transport models.

Some cellular uptake systems for (anti)folates function optimally at acidic pH. We have tested whether this also applies to efflux from cells by breast cancer resistance protein (BCRP; ABCG2), which has been reported to transport folic acid, methotrexate, and methotrexate di- and triglutamate at physiological pH. Using Spodoptera frugiperda-BCRP membrane vesicles, we showed that the ATP-dependent vesicular transport of 1 muM methotrexate by BCRP is 5-fold higher at pH 5.5 than at physiological pH. The transport of methotrexate was saturable at pH 5.5, with apparent Km and Vmax values of 1.3 +/- 0.2 mM and 44 +/- 2.5 nmol/mg of protein/min, respectively, but was linear with drug concentration at pH 7.3 up to 6 mM methotrexate. In contrast to recent reports, we did not detect transport of methotrexate diglutamate at physiological pH, but we did find transport at pH 5.5. We also found that 7-hydroxy-methotrexate, the major metabolite of methotrexate, is transported by BCRP both at physiological pH and (more efficiently) at low pH. The pH effect was also observed in intact BCRP-overexpressing cells: we found a 3-fold higher level of resistance to both methotrexate and the prototypical BCRP substrate mitoxantrone at pH 6.5 as at physiological pH. Furthermore, with MDCKII-BCRP monolayers, we found that resveratrol, which is a neutral compound at pH < or = 7.4, is efficiently transported by BCRP at pH 6.0, whereas we did not detect active transport at pH 7.4. We conclude that BCRP transports substrate drugs more efficiently at low pH, independent of the dissociation status of the substrate.