Programmed cell death-4 (PDCD4) is a recently discovered tumor suppressor protein that inhibits protein synthesis by suppression of translation initiation. We investigated the role and the regulation of PDCD4 in the terminal differentiation of acute myeloid leukemia (AML) cells. Expression of PDCD4 was markedly up-regulated during all-trans retinoic acid (ATRA)-induced granulocytic differentiation in NB4 and HL60 AML cell lines and in primary human promyelocytic leukemia (AML-M3) and ...

PARP inhibitors are considered promising anticancer agents and currently being tested in clinical trials in hereditary breast cancer patients harboring mutations in BRCA1 and BRCA2 genes. In this study, we investigated the antiproliferative effects and mechanism of PARP inhibitors ABT-888 (Veliparib), BSI-201 (Iniparib) and AZD228 (Olaparib) in breast cancer cell lines with BRCA1 or BRCA2 mutations and 9 different BRCA wild-type cell lines with BRCA1 allelic loss. We found that AZD2281 ...

Elevated expression of tissue transglutaminase (TG2) in cancer cells has been implicated in the development of drug resistance and metastatic phenotypes. However, the role and the mechanisms that regulate TG2 expression remain elusive. Here, we provide evidence that protein kinase Cdelta (PKCdelta) regulates TG2 expression, which in turn inhibits autophagy, a type II programmed cell death, in pancreatic cancer cells that are frequently insensitive to standard chemotherapeutic agents. ...

More than 75% of breast cancers that develop in BRCA1 mutation carriers are triple-negative breast cancers (TNBC). The aim of this study was to compare the recurrence-free survival (RFS) and overall survival (OS) in high-risk patients with TNBC with and without deleterious BRCA1/2 mutations. A total of 227 women with TNBC who were referred for genetic counseling and underwent BRCA genetic testing between 1997 and 2010 were included in the study. The relationships between clinical ...

Overexpression of p70S6K in breast cancer patients is associated with aggressive disease and poor prognosis. Recent studies showed that patients with breast cancer with increased p70S6K phosphorylation had poor survival and increased metastasis. The purpose of our study was to determine whether knockdown of p70S6K would inhibit cell growth, invasion, and metastasis in breast cancer. We therefore stably knocked down p70S6K expression in MDA-231, a highly metastatic breast cancer cell ...

The epidermal growth factor receptor (EGFR) signaling pathway has emerged as a promising target for cancer therapy. EGFR tyrosine kinase inhibitors (TKI) such as erlotinib have been approved for cancer treatment but have shown very limited activity in breast cancer patients. Clarifying the molecular mechanism underlying resistance to EGFR TKIs could lead to more effective treatment against breast cancer. We previously reported that the sensitivity of breast cancer cells to erlotinib is ...

Clear cell carcinoma (CCC) of the ovary tends to show resistance to standard chemotherapy, which results in poor survival for patients with CCC. Developing a novel therapeutic strategy is imperative to improve patient prognosis. Epidermal growth factor receptor (EGFR) is frequently expressed in epithelial ovarian cancer. One of the major downstream targets of the EGFR signaling cascade is extracellular signal-related kinase (ERK). PEA-15, a 15-kDa phosphoprotein, can sequester ERK in the ...

Inherited polymorphisms in the genes controlling the cell cycle or functioning in the DNA repair mechanisms may impair their function and contribute to genetic susceptibility. Abnormalities in the DNA repair have been reported in head and neck cancer. The XRCC1 gene functions in singlestrand break and base excision repair processes. In this study, two polymorphisms of the XRCC1 gene, Arg194Trp and Arg399G1n were investigated in 95 patients with head and neck carcinoma. The polymorphic ...

Bcl-2 is overexpressed in about a half of human cancers and 50-70% of breast cancer patients, thereby conferring resistance to conventional therapies and making it an excellent therapeutic target. Small interfering RNA (siRNA) offers novel and powerful tools for specific gene silencing and molecularly targeted therapy. Here, we show that therapeutic silencing of Bcl-2 by systemically administered nanoliposomal (NL)-Bcl-2 siRNA (0.15 mg siRNA/kg, intravenous) twice a week leads to ...

BACKGROUND: The aim of this study was to investigate the human leukocyte antigen (HLA) characteristics of Turkish alopecia areata patients, and the correlation of the HLA profile with age of onset, severity and duration of the disease, presence of ophiasis, and family history.

METHODS: A total of 88 patients with alopecia areata, alopecia totalis, or alopecia universalis were compared with 100 healthy controls. HLA typing was performed by the Terasaki microlymphocytotoxicity ...

BACKGROUND: Recent reports indicated a significant association between fixed drug eruption (FDE) and HLA class I antigens. A strong correlation was found between B22 antigen and feprazone-induced FDE.

OBJECTIVE: Our aim was to investigate the association between HLA class I antigens and FDE in Turkey, a country where feprazone is not on the market and trimethoprim-sulfamethoxazole is most often the offending drug.

METHODS: HLA class I typing was performed by lymphocytotoxicity assay in ...

The selective estrogen receptor modulators (SERM), Tamoxifen and raloxifen reduce risk breast cancer. Patient acceptance of SERMs for breast cancer prevention is low due to toxicities. New agents with a better toxicity profile are needed. Aromatase inhibitors (AI) reduce the risk of contralateral breast cancer and risk of new breast cancer in high risk women. However, the mechanism by which AIs reduce breast risk is not known. Surrogate biomarkers are needed to evaluate the effect of ...

Translation initiation and activity of eukaryotic initiation factor-alpha (eIF2α), the rate-limiting step of translation initiation, is often overactivated in malignant cells. Here, we investigated the regulation and role of eIF2α in acute promyelocytic (APL) and acute myeloid leukemia (AML) cells in response to all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), the front-line therapies in APL. ATRA and ATO induce Ser-51 phosphorylation (inactivation) of eIF2α, through the ...