Background:Sorafenib is the only drug approved for the treatment of hepatocellular carcinoma (HCC). The bioenergetic propensity of cancer cells has been correlated to anticancer drug resistance, but such correlation is unclear in sorafenib resistance of HCC.Methods:Six sorafenib-naive HCC cell lines and one sorafenib-resistant HCC cell line (Huh-7R; derived from sorafenib-sensitive Huh-7) were used. The bioenergetic propensity was calculated by measurement of lactate in the presence or absence of oligomycin. Dichloroacetate (DCA), a pyruvate dehydrogenase kinase (PDK) inhibitor, and siRNA of hexokinase 2 (HK2) were used to target relevant pathways of cancer metabolism. Cell viability, mitochondrial membrane potential, and sub-G1 fraction were measured for in vitro efficacy. Reactive oxygen species (ROS), adenosine triphosphate (ATP) and glucose uptake were also measured. A subcutaneous xenograft mouse model was used for in vivo efficacy.Results:The bioenergetic propensity for using glycolysis correlated with decreased sorafenib sensitivity (R2=0.9067, among sorafenib-naive cell lines; P=0.003, compared between Huh-7 and Huh-7 R). DCA reduced lactate production and increased ROS and ATP, indicating activation of oxidative phosphorylation (OXPHOS). DCA markedly sensitised sorafenib-resistant HCC cells to sorafenib-induced apoptosis (sub-G1 (combination vs sorafenib): Hep3B, 65.4±8.4% vs 13±2.9% Huh-7 R, 25.3± 5.7% vs 4.3±1.5% each P<0.0001), whereas siRNA of HK2 did not. Sorafenib (10 mg kg−1 per day) plus DCA (100 mg kg−1 per day) also resulted in superior tumour regression than sorafenib alone in mice (tumour size: −87% vs −36%, P<0.001).Conclusion:The bioenergetic propensity is a potentially useful predictive biomarker of sorafenib sensitivity, and activation of OXPHOS by PDK inhibitors may overcome sorafenib resistance of HCC.

SEA,RCH TECHNIQUES AND RESULTSA rntrnightf,)rward nmrrh rnttatr~y Fmpl;Iym the" l)lnnin~nflhe ;ky rnpntirdly, according to th~angular rmoluti(jn~)f thr nrray, where u is the angular resolution of the detector, For the case with no a prsoti source location (using the qvents in the data set to determine the center of each bin) the optimrd bin radius is /~Limes larger, The angular resolution of the detector is 0.7' and I%", ZP * 0.02 therefore a circular bin with radius 2.1°is used for this search.The search window that maximises the sensitivity to evaporating black holes depends on the energy threshold of the detector and the observed cosmic-ray background rate.

Common genetic alteration in cancer genomes is implicated for embracing an aberrant cancer gene participated in tumor progression. In this study, we identified a somatic mutated LIM and cysteine-rich domains-1 (LMCD1) as a putative metastatic oncogene in human hepatocellular carcinoma (HCC) using integrated genomic approaches. In addition to revealing genomic amplification and gene upregulation, we identified recurrent E135K (3/48 cases) mutations in HCC tissues and K237R mutation in the PLC/PRF/5 HCC cell line. Expression of mutant LMCD1 E135K or K237R reduced the stress fiber assembly, increased cortical actin accumulation and induced lamellipodial extension. Consistently, these mutations enhanced cell migration and showed activation of the Rac1-signaling pathway. Inhibition of the LMCD1/Rac1 pathway by an LMCD1 short-hairpin RNA (shLMCD1) or the Rac1 inhibitor NSC23766 suppressed the mutationmediated lamellipodial protrusion and cell migration. In PLC/PRF/5 cells with endogenous K237R mutation, cell migration was enhanced by estrogen-induced LMCD1 expression but reversed by shLMCD1 treatment. Moreover, overexpression of LMCD1 E135K mutation significantly promoted systemic lung metastasis in a murine tail vein injection model. Together, our results suggest that LMCD1 mutations are potential oncogenic events in HCC metastasis to promote cell migration through the Rac1-signaling pathway.

Data froin an extensive air shower detector of ultrahigh-energy cosmic rays shows shado~ving of the cosmic-ray flus by the Moon and the Sun with signficance of 4.9 standard cleviations. This is the first observation of such shadowing. The effect has been used to determine that the angular resolution of the detector is 0.75' t",.,y3:.