γ-Glutamyl hydrolase modulation and folate influence chemosensitivity of cancer cells to 5-fluorouracil and methotrexate.

Background: γ-Glutamyl hydrolase (GGH) regulates intracellular folate and antifolates for optimal nucleotide biosynthesis and antifolate-induced cytotoxicity, respectively. The modulation of GGH may therefore affect chemosensitivity of cancer cells, and exogenous folate levels may further modify this effect.

Methods: We generated a novel model of GGH modulation in human HCT116 and MDA-MB-435 cancer cells and investigated the effect of GGH modulation on chemosensitivity to 5-fluorouracil (5FU) and methotrexate (MTX) at different folate concentrations in vitro and in vivo.

Can targeted therapy be successful without metronomic scheduling?

In medical oncology, targeted therapy has emerged over the last decade, as the most promising strategy to fight cancer. In addition, a more complete understanding of tumor heterogeneity and pharmacology of the more conventional anti-cancer agents has led to development of metronomic chemotherapy (MC) (i.e.

Farletuzumab, an anti-folate receptor α antibody, does not block binding of folate or anti-folates to receptor nor does it alter the potency of anti-folates in vitro.

Purpose: Folate is a cofactor in the synthesis of purines and pyrimidines; folate analogs are potent cytotoxic drugs. Folate receptor alpha (FRα), a protein-mediating cellular accumulation of folate (and anti-folates), has limited expression in normal tissues and is overexpressed by numerous carcinomas. Limited distribution and high affinity for folic acid have resulted in the development of antibodies or the use of folic acid coupled to toxins or radionuclides as therapeutic and imaging agents.

A phase 1 study of nifurtimox in patients with relapsed/refractory neuroblastoma.

The primary aim of this phase 1 study was to determine the maximum tolerated dose (MTD) and evaluate the safety of nifurtimox alone and in combination with cyclophosphamide and topotecan in multiple relapsed/refractory neuroblastoma pediatric patients. The secondary aim was to evaluate the pharmacokinetics of nifurtimox and the treatment response. To these ends, we performed a phase 1 dose escalation trial of daily oral nifurtimox with toxicity monitoring to determine the MTD, followed by 3 cycles of nifurtimox in combination with cyclophosphamide and topotecan.

Clinical aspects of pharmacogenetics of pain and co-morbidities of emotional distress.

The majority of patients treated for cancer will have pain at some point in their journey. It will be due to the disease (e.g.

Heparin and suramin alter plitidepsin uptake via inhibition of GPCR coupled signaling.

Plitidepsin (Aplidin) is a novel antitumor agent, derived from the mediterranean tunicate Aplidium albicans, and is currently in phase ii clinical trials with evidence of activity in heavily pretreated multiple myeloma, renal cell carcinoma, melanoma and neuroblastoma patients. As compared to its parental compound didemnin B, plitidepsin has shown a better therapeutic index with less bone marrow toxicity, cardiotoxicity and neurotoxicity in patients and a more potent cytotoxic effect in several tumor cell lines. As sensitivity to the drug varies between cell lines and fresh leukemia samples, we performed studies on transport of plitidepsin in leukemia and lymphoma cell lines to determine the mechanism of uptake.

Regulation of folate receptor internalization by protein kinase C alpha.

The glycosyl-phosphatidylinositol anchored folate receptor (FR) mediates selective delivery of a broad range of experimental drugs to the receptor-rich tumors, but molecular mechanisms controlling FR internalization have not been adequately studied. FR quantitatively recycles between the cell surface and endocytic compartments via a Cdc42-dependent pinocytic pathway. Protein kinase C (PKC) activators including diacylglycerol and phorbol ester have previously been reported to increase the proportion of FR on the cell surface.

Functional folate receptor alpha is elevated in the blood of ovarian cancer patients.

Background: Despite low incidence, ovarian cancer is the fifth leading cause of cancer deaths and it has the highest mortality rate of all gynecologic malignancies among US women. The mortality rate would be reduced with an early detection marker. The folate receptor alpha (FRalpha) is one logical choice for a biomarker because of its prevalent overexpression in ovarian cancer and its exclusive expression in only a few normal tissues.

Hemolysis and elevated transaminases imitating severe preeclampsia.

Background: Illnesses coincident with pregnancy may present similarly to preeclampsia or may be mistaken for severe preeclampsia or hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome. Distinguishing these imitators from preeclampsia is important to allow for appropriate treatment and to avoid unnecessary delivery.

Case: A primigravida at 32 2/7 weeks of gestation transferred to our institution with flu-like symptoms, anemia, jaundice, and elevated liver function tests.

Folate homeostasis in cerebrospinal fluid during therapy for acute lymphoblastic leukemia.

The neurotoxic effects of therapy for childhood acute lymphoblastic leukemia can result in leukoencephalopathy or measurable deficits in cognitive function. However, there are no validated biomarkers that allow the identification of those patients at greatest risk. With the objective of identifying such predictors, cerebrospinal fluid collected from 53 patients over 2.

Use of a novel genetic mouse model to investigate the role of folate in colitis-associated colon cancer.

Inflammatory bowel disease (IBD) patients are at high risk for developing folate deficiency and colon cancer. Since it is difficult to study the subtle global and gene-specific epigenetic mechanisms involved in folate-mediated tumor initiation and promotion, we have generated genetically modified mouse models by targeting the reduced folate carrier (RFC1) and folate-binding protein (Folbp1) genes. The transgenic mice were fed semi-purified diets for 8 weeks containing either normal (2 mg) or deficient (0.