Regulation in the targeting of TRAIL receptor 1 to cell surface via GODZ for TRAIL sensitivity in tumor cells

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its receptors, TRAIL-R1 (DR4) and TRAIL-R2 (DR5), promote the selective clearing of various malignancies by inducing apoptosis, holding the promise as a potent therapeutic agent for anticancer. Though DR4 and DR5 have high sequence similarity, differential regulation of both receptors in human tumor cells remains largely unexplored. Here, we repot that golgi-specific Asp-His-His-Cys (DHHC) zinc finger protein (GODZ) regulates TRAIL/DR4-mediated apoptosis. Using the SOS protein recruitment-yeast two-hybrid screening, we isolated GODZ that interacted with the death domain of DR4. GODZ binds to DR4, but not to DR5, through the DHHC and the C-terminal transmembrane domain. Expression level of GODZ affects apoptosis of tumor cells triggered by TRAIL, but not that induced by TNF-α/cycloheximide (CHX) or DNA-damaging drugs. In parallel, GODZ functions to localize DR4 to the plasma membrane (PM) via DHHC motif. Also, introduction of mutation into the cysteine-rich motif of DR4 results in its mistargeting and attenuates TRAIL- or GODZ-mediated apoptosis. Interestingly, GODZ expression is highly downregulated in Hep-3B tumor cells, which show resistance to TRAIL. However, reconstitution of GODZ expression enhances the targeting of DR4 to cell surface and sensitizes Hep-3B cells to TRAIL. Taken together, these data establish that GODZ is a novel DR4-selective regulator responsible for targeting of DR4 to the PM, and thereby for TRAIL-induced apoptosis.

P4-11-20: Observational Study of Body Weight Changes and Metabolic Syndrome in Breast Cancer Patients Receiving Adjuvant Therapy: Characteristics of Dietary Pattern in Korean Breast Cancer Patients

Backgroud: Obesity, postdiagnosis weight gain, and presence of metabolic syndrome in breast cancer are reported to adversely affect survival among breast cancer survivors. Most of the studies on weight gain and metabolic syndrome in breast cancer are from Western countries and few information is available on Asian population. We designed this prospective observational study to characterize weight and metabolic changes during adjuvant treatment in women with early breast cancer and to identify factors associated with occurrence of metabolic syndrome, focusing on dietary pattern.

Methods: Patients aged 18–75 who underwent curative surgery with stage I-III invasive breast cancer were enrolled from 2008 to 2010. We measured glucose (FBS), hemoglobin A1c (HbA1c), total cholesterol (TC), HDL cholesterol, and triglyceride (TG) level in fasting serum samples before starting adjuvant therapy, at 6 months and 12 months after enrollment. Body weight, body mass index (BMI), body fat mass, and percent body fat at baseline, 6 months, and 12 months were also measured. Dietary intake was assessed using valid semi-quantitative Food frequency questionnaire (FFQ).

Results: Total of 63 patients were enrolled. Median age of the enrolled patients were 48 (range, 25–68), with premenopausal/postmenopausal 40 (63.5%)/ 23 (36.5%). Fifty (82.0%) and 10 (16.4%) received adjuvant chemotherapy followed by hormone therapy and hormone therapy alone. Hormone receptor positive (ER+/PR+) and HER2 positive cancer accounted for 52 (83.9%) and 7 (12.1%). Mean FBS, HbA1c, TC, HDL, and TG level was 99.9 mg/dL (range, 83–159), 5.59 mg/dL (range, 4.8−7.5), 197.4 mg/dL (125-298), 51.9 mg/dL (range, 30–90), and 119.7 mg/dL (42-371). Mean height, weight, and BMI was 158 cm (range, 149–169), 61.7kg (range, 46.2−96.0), and 24.7 kg/m2 (range, 18.7−35.7), respectively. According to the WHO and NTH guidelines for Asian, normal (BMI 18.5−22.9), overweight (BMI 23–24.9), and obesity (BMI≥25) was 18 (28.6%), 13 (20.6%), and 32 (50.8%), respectively. Number of patients with metabolic syndrome was 18 (34%). Mean BMI (26.1 vs 24.0, p=0.021) and TG (180.6 vs 92.0, p<0.001) was higher, HDL cholesterol was lower (42.2 vs 57.3, p<0.001) in patients with metabolic syndrome. Composition of daily calorie intake consisted of 13.5% (range 10.7−21.8) of protein, 6.7% (range, 3.3−22.1) of fat, and 70.1% (range, 28.1−79.5) of carbohydrate. The presence of metabolic syndrome was associated with a higher carbohydrate intake (carbohydrate intake per ideal body weight>6.0) (p=0.071). The TG level of patients who indigested high carbohydrate was significantly higher (143.8 vs 102.9, p=0.023). The HDL level of patients who took high fat diet (>20% of total calorie) was lower (45.3 vs 53.5, p=0.045).

Conclusion: In our cohort of Korean breast cancer patients, 34% had metabolic syndrome at baseline. Those patients with metabolic syndrome consumed higher proportion of carbohydrate, which resulted in significantly higher level of TG. Our data suggest that composition of calorie intake is different in Asian population compared to Western countries, warranting for reappraisal on the recommendation on life style modification and diet.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-11-20.

Total synthesis of diptoindonesin G via a highly efficient domino cyclodehydration/intramolecular Friedel-Crafts acylation/regioselective demethylation sequence

A highly efficient total synthesis of diptoindonesin G is described employing a domino dehydrative cyclization/intramolecular Friedel-Crafts acylation/regioselective demethylation reaction of aryloxyketone 7 by the action of BCl(3) wherein the tetracyclic 6H-anthra[1,9-bc]furan-6-one skeleton was constructed via the 3-arylbenzofuran in a one-pot manner. This is the first example of the strategic combination of these three reactions in a cascade fashion. The routes presented here allow for direct access to diptoindonesin G and its analogues.

A mitochondria-targeted vitamin E derivative decreases hepatic oxidative stress and inhibits fat deposition in mice

Our objective in this study was to determine whether a mitochondria-targeted vitamin E derivative (MitoVit E) would decrease oxidative stress and associated obesity by preventing a previously proposed aconitase inhibition cascade. Sixty-four mice were fed a high-fat (HF) diet for 5 wk. They were then switched to either a low-fat (LF) or a medium-fat (MF) diet and gavaged with MitoVit E (40 mg MitoVit E x kg body weight(-1)) or drug vehicle (10% ethanol in 0.9% NaCl solution) every other day for 5 wk. Epididymal fat weight, as well as liver lipid and remaining carcass lipid, were significantly lower in the MF group receiving MitoVit E (MF-E) than in the MF group receiving vehicle only (MF-C). Liver mitochondrial H(2)O(2) production and the protein carbonyl level were also significantly lower in MF-E than in MF-C mice. In contrast, none of the biochemical variables (aconitase activity, ATP and H(2)O(2) production, and protein carbonyl level) in the muscle mitochondria were modified by MitoVit E in either MF or LF groups. Expression of acetyl-CoA carboxylase and fatty acid synthase in both liver and adipose tissue of MF groups was not affected by MitoVit E. However, expression of carnitine palmitoyltransferase 1a in the liver and uncoupling protein 2 in adipose tissue were significantly enhanced by MitoVit E in both LF and MF groups. In conclusion, MitoVit E attenuates hepatic oxidative stress and inhibits fat deposition in mice but not through alleviation of the aconitase inhibition cascade.