Elevated glucose uptake and production of lactate are common features of cancer cells. Among many tumor-promoting effects, lactate inhibits immune responses and is positively correlated with radioresistance. Dichloroacetate (DCA) is an inhibitor of pyruvate dehydrogenase kinase that decreases lactate production.
View Article and Find Full Text PDFBackground: Nicotinamide adenine dinucleotide (NAD+) is vital for not only energy metabolism but also signaling pathways. A major source of NAD+ depletion is the activation of poly (ADP-ribose) polymerase (PARP) in response to DNA damage. We have previously demonstrated that metformin can cause both caspase-dependent cell death and PARP-dependent cell death in the MCF7 breast cancer cells but not in the MDA-MB-231 (231) breast cancer cells while in high-glucose media.
View Article and Find Full Text PDFHistorically, the clinical utility of oncolytic virotherapy as a treatment for a wide range of cancer types was first demonstrated by three pilot human clinical trials conducted in Japan in the 1970s and 1980s using a wild-type Urabe mumps virus (MuV) clinical isolate. Using a sample of the actual original oncolytic Urabe MuV clinical trial virus stock (MuV-U-Japan) used in these Japanese clinical trials, we found that MuV-U-Japan consisted of a wide variety of very closely related Urabe MuVs that differed by an average of only three amino acids. Two MuV-U-Japan isolates, MuV-UA and MuV-UC, potently killed a panel of established human breast cancer cell lines , significantly extended survival of nude mice with human triple-negative breast cancer (TNBC) MDA-MB-231 tumor xenografts , and demonstrated significant killing activity against breast cancer patient-derived xenograft (PDX) cell lines grown as 3D organoids, including PDXs from patients resistant to anthracycline- and taxane-based chemotherapy.
View Article and Find Full Text PDFNeoadjuvant chemotherapy (NAC) remains the cornerstone of the treatment for triple negative breast cancer (TNBC), with the goal of complete eradication of disease. However, for patients with residual disease after NAC, recurrence and mortality rates are high and the identification of novel therapeutic targets is urgently needed. We quantified tyrosine phosphorylation (pTyr)-mediated signaling networks in chemotherapy sensitive (CS) and resistant (CR) TNBC patient-derived xenografts (PDX), to gain novel therapeutic insights.
View Article and Find Full Text PDFTriggering receptor expressed on myeloid cell 2 (TREM2) is linked to risk of neurodegenerative disease. However, the function of TREM2 in neurodegeneration is still not fully understood. Here, we investigated the role of microglial TREM2 in TAR DNA-binding protein 43 (TDP-43)-related neurodegeneration using virus-mediated and transgenic mouse models.
View Article and Find Full Text PDFTher Adv Med Oncol
June 2021
Background: Trastuzumab (Herceptin) is the key systemic therapy for HER2-positive breast cancer. However, the initial response rate is limited to approximately 50% in patients. Moreover, most patients, especially at an advanced stage, eventually develop acquired resistance.
View Article and Find Full Text PDFThe application of patient-derived xenografts (PDX) in drug screening and testing is a costly and time-consuming endeavor. While cell lines permit extensive mechanistic studies, many human breast cancer cell lines lack patient characteristics and clinical treatment information. Establishing cell lines that retain patient's genetic and drug response information would enable greater drug screening and mechanistic studies.
View Article and Find Full Text PDFNovel therapeutic strategies for Alzheimer's disease (AD) are of the greatest priority given the consistent failure of recent clinical trials focused on Aβ or pTau. Earlier, we demonstrated that mild mitochondrial complex I inhibitor CP2 blocks neurodegeneration and cognitive decline in multiple mouse models of AD. To evaluate the safety of CP2 in humans, we performed a genome-wide association study (GWAS) using 196 lymphoblastoid cell lines and identified 11 SNP loci and 64 mRNA expression probe sets that potentially associate with CP2 susceptibility.
View Article and Find Full Text PDFOf the deaths attributed to cancer, 90% are due to metastasis. Treatments that prevent or cure metastasis remain elusive. Low expression of extracellular superoxide dismutase (EcSOD or SOD3) has been associated with poor outcomes and increased metastatic potential in multiple types of cancer.
View Article and Find Full Text PDFBackground: The role of tumor protein D54 in breast cancer has not been studied and its function in breast cancer remains unclear. In our previous pharmacogenomic studies using lymphoblastoid cell line (LCL), this protein has been identified to affect metformin response. Although metformin has been widely studied as a prophylactic and chemotherapeutic drug, there is still a lack of biomarkers predicting the response to metformin in breast cancer.
View Article and Find Full Text PDFAnastrozole is a widely prescribed aromatase inhibitor for the therapy of estrogen receptor positive (ER+) breast cancer. We performed a genome-wide association study (GWAS) for plasma anastrozole concentrations in 687 postmenopausal women with ER+ breast cancer. The top single-nucleotide polymorphism (SNP) signal mapped across SLC38A7 (rs11648166, P = 2.
View Article and Find Full Text PDFTriple-negative breast cancer (TNBC) is a heterogeneous disease with poor prognosis that lacks targeted therapies, especially in patients with chemotherapy-resistant disease. Since DNA methylation-induced silencing of tumor suppressors is common in cancer, reversal of promoter DNA hypermethylation by 5-aza-2'-deoxycytidine (decitabine), an FDA-approved DNA methyltransferase (DNMT) inhibitor, has proven effective in treating hematological neoplasms. However, its antitumor effect varies in solid tumors, stressing the importance of identifying biomarkers predictive of therapeutic response.
View Article and Find Full Text PDFAKT signaling is modulated by a complex network of regulatory proteins and is commonly deregulated in cancer. Here, we present a dual mechanism of AKT regulation by the ERBB receptor feedback inhibitor 1 (ERRFI1). We show that in cells expressing high levels of EGFR, ERRF1 inhibits growth and enhances responses to chemotherapy.
View Article and Find Full Text PDFDifferent cancer cells exhibit altered sensitivity to metformin treatment. Recent studies suggest these findings may be due in part to the common cell culture practice of utilizing high glucose, and when glucose is lowered, metformin becomes increasingly cytotoxic to cancer cells. In low glucose conditions ranging from 0 to 5 mM, metformin was cytotoxic to breast cancer cell lines MCF7, MDAMB231 and SKBR3, and ovarian cancer cell lines OVCAR3, and PA-1.
View Article and Find Full Text PDFThe unique metabolism of breast cancer cells provides interest in exploiting this phenomenon therapeutically. Metformin, a promising breast cancer therapeutic, targets complex I of the electron transport chain leading to an accumulation of reactive oxygen species (ROS) that eventually lead to cell death. Inhibition of complex I leads to lactate production, a metabolic byproduct already highly produced by reprogrammed cancer cells and associated with a poor prognosis.
View Article and Find Full Text PDFThere is substantial evidence that metformin, a drug used to treat type 2 diabetics, is potentially useful as a therapeutic agent for cancer. However, a better understanding of the molecular mechanisms through which metformin promotes cell-cycle arrest and cell death of cancer cells is necessary. It will also be important to understand how the response of tumor cells differs from normal cells and why some tumor cells are resistant to the effects of metformin.
View Article and Find Full Text PDFBackground: The antihyperglycemic drug metformin may have beneficial effects on the prevention and treatment of cancer. Metformin is known to activate AMP-activated protein kinase (AMPK). It has also been shown to inhibit cyclin D1 expression and proliferation of some cultured cancer cells.
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