Rlip Depletion Suppresses Growth of Breast Cancer.

RLIP76 (RAL-binding protein-1, Rlip) is a stress-protective mercapturic-acid-pathway transporter protein that also plays a key role in regulating clathrin-dependent endocytosis as a Ral effector. Targeted inhibition or depletion of Rlip causes regression of xenografts of many cancers and is capable of abrogating tumor formation in p53-null mice. This is associated with the reversion of the abnormal methylomic profile of p53-null mice to wild-type. In a query of The Cancer Genome Atlas (TCGA) databases, we found that Rlip expression was associated with poor survival and with significant differences in the frequencies of PIK3CA mutation, MYC amplification, and CDKN2A/B deletion, which were the most commonly mutated, amplified, and deleted genes, respectively, among TCGA breast cancer patients. We conducted the present study to further examine the effects of Rlip inhibition and to evaluate the in vitro and in vivo efficacy in breast cancer. Using immunogold electron microscopy, we found that plasma-membrane Rlip was accessible to cell-surface antibodies in the MCF7 (ER+) breast cancer cell line. Rlip depletion resulted in decreased survival of MCF7 and MDA-MB-231 cells and increased terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positivity and DNA laddering, indicating apoptotic cell death. Additionally, in vitro knockdown of Rlip inhibited EGF endocytosis and WNT/MAPK signaling. Xenograft studies in nude mice showed regression of breast cancer via antisense-mediated depletion of Rlip mRNA as well as by anti-Rlip antibody. Finally, knockdown of Rlip by antisense locked nucleic acid oligonucleotides increased markers for apoptotic signaling and decreased markers for proliferation, angiogenesis, and cell cycling in MCF7 and MDA-MB-231luc xenografts. Our findings validate Rlip as an attractive target in breast cancer.

Hepatitis B Reactivation After Ifosfamide Therapy for Retroperitoneal Sarcoma.

BACKGROUND: Patients receiving cancer treatment are at risk for hepatitis B virus (HBV) reactivation. Ifosfamide is an alkylating agent and is considered to be one of the important drugs for the treatment of metastatic sarcoma. No association of ifosfamide and HBV reactivation has been reported so far. CASE REPORT: We report a case of a 61-year-old Asian man with metastatic retroperitoneal liposarcoma who was HBcAb positive and was treated with ifosfamide and dacarbazine, developed HBV reactivation secondary to ifosfamide requiring treatment with tenofovir. To the best of our knowledge, this is the first report describing HBV reactivation in a patient with positive HBcAb who was treated with ifosfamide. CONCLUSIONS: We recommend close surveillance of possible HBV reactivation while employing ifosfamide chemotherapy.

Liver Metastases in Prostate Carcinoma Represent a Relatively Aggressive Subtype Refractory to Hormonal Therapy and Short-Duration Response to Docetaxel Monotherapy.

BACKGROUND: We report a single institution's experience from a small series of patients suggesting that liver metastasis in metastatic castration-refractory prostate cancer (mCRPC) represents a relatively aggressive subtype that is refractory to hormonal manipulation treatment, including luteinizing hormone-releasing hormone agonist (LA) and abiraterone (Ab) therapy, although docetaxel is briefly effective. METHODS: Between 2007 and 2013, six patients with prostate cancer with liver metastases were analyzed. Biochemical response was defined as > 50% decrease in prostate-specific antigen (PSA) value. RESULTS: Two patients who presented with liver metastases died in less than 3 months after LA therapy. Two out of three patients (one died while receiving chemotherapy) received Ab after chemotherapy did not show any response and died while on therapy. One patient who presented with lung metastases initially received LA therapy and progressed on it with liver metastases in < 6 months. Thus, five of six patients did not respond to hormone therapy including LA and Ab. Three patients who received docetaxel after LA therapy had more than 50% objective PSA response with a mean survival of 4 months. CONCLUSIONS: No literature addresses the response to hormone treatment in hepatic metastasis in prostate carcinoma. This small series suggests that liver metastases in prostate carcinoma represent a relatively aggressive subset against which hormonal therapy, including the LA and Ab, appears to be ineffective. Although our patients responded to docetaxel chemotherapy, their responses were of short duration. A further clinical trial involving more patients will be necessary to substantiate our findings.