Low PTEN expression and overexpression of phosphorylated AktSer473 and AktThr308 are associated with poor overall survival in upper tract urothelial carcinoma.

The PI3K/Akt signaling pathway serves an essential role in various cellular processes, including cell growth, survival, cell motility, angiogenesis and cell metabolism. Loss of PTEN expression and hyperactivation of Akt can result in tumorigenesis. Previous studies observed expression of the Akt protein and absence of the PTEN protein in bladder cancer and non-small cell lung carcinoma tissues. The aim of the present study was to evaluate the expression status and prognostic value of PTEN and the PI3K/Akt signaling pathway in Taiwanese patients with upper tract urothelial carcinoma (UTUC). Archival formalin-fixed, paraffin-embedded (FFPE) tissues from 65 UTUC cases were stained via immunohistochemistry for PTEN, phosphorylated (p)Akt serine (Ser)473 and pAkt threonine (Thr)308. The expression levels of each protein were significantly correlated with clinicopathological parameters. PTEN, pAktSer473 and pAktThr308 protein expression levels were higher in adjacent normal tissues compared with those in tumor tissues. Cytoplasmic PTEN protein expression levels were lower in high-stage tumors compared with those in low-stage tumors, and nuclear and cytoplasmic pAktThr308 protein expression levels were higher in high-grade tumors compared with those in low-grade tumors. Univariate analysis showed that high pathological tumor stage (pT2-4) [P=0.01; hazard ratio (HR)=3.40; 95% confidence interval (CI), 1.34-8.60], metastatic status (P=0.003; HR=3.55, 95% CI, 1.55-8.11), low cytoplasmic PTEN protein expression levels (P=0.016; HR=3.14; 95% CI, 1.24-7.95) and high cytoplasmic pAktSer473 protein expression levels (P=0.019, HR=2.71, 95% CI, 1.18-6.21) were predictive of poor overall survival. However, only metastatic status (P=0.031; HR=2.73; 95% CI, 1.10-6.78), low cytoplasmic PTEN protein expression levels (P=0.017; HR=3.29; 95% CI, 1.24-8.73) and high cytoplasmic pAktSer473 protein expression levels (P=0.027; HR=2.64; 95% CI, 1.12-6.23) remained significant in the multivariate analysis. Kaplan-Meier survival analysis showed that high T stage, metastasis, low expression levels of cytoplasmic PTEN protein and high expression levels of cytoplasmic pAktSer473 protein were significantly associated with poor survival (P=0.006, 0.001, 0.011 and 0.014, respectively). Co-expression of PTENlow/pAktSer473/high and pAktThr308/high phenotypes was associated with a less favorable overall survival (P=0.001). Overall, the present findings demonstrated that low expression levels of PTEN and high expression levels of pAktSer473 and pAktThr308 were predictors for poor overall survival in patients with UTUC.

A rare case of hyperammonaemic encephalopathy.

A 75-year-old female patient presented to the accident and emergency department following a collapse. She was treated for a saddle pulmonary embolism and underlying urinary tract infection. However, 48 hours later she was found to have reduced consciousness with no apparent cause (Glasgow Coma Scale of 8 out of 15). Subsequent blood results revealed a highammonia level. After reflection into her medical history, it was found that she had bladder exstrophy, which was managed with urinary diversion surgery as an infant, and her presentation was a rare complication of this operation.

EPA significantly improves anti-EGFR targeted therapy by regulating miR-378 expression in colorectal cancer.

It is known that colorectal cancer (CRC) cells containing mutations of the genes KRAS and BRAF are predominate mechanisms causing resistance to epidermal growth factor receptor (EGFR) inhibitors, and commonly exhibit a lower expression of microRNA-378 (miR-378) when compared with the wild type. In the present study, the aim was to determine the possible mechanism which associates miR-378 with the mitogen-activated protein kinase pathway, and to determine the efficiency of eicosapentaenoic acid ethyl ester (EPA) in its ability to restore sensitivity towards cetuximab, an EGFR inhibitor. The results demonstrated that a combined treatment of 40 µM EPA with 0.2 µM cetuximab can significantly suppress the cell growth in KRAS-mutant and control wild-type cells. Furthermore, the higher phosphorylated protein level of extracellular-signal-regulated kinase 1/2 was notable in KRAS EPA-treated cells (P=0.006-0.047) and resulted in significantly increased cell death; however, inconsistent results were indicated in EPA-treated BRAF-mutant cells, compared with the original cells (without treatment). KRAS-mutant and wild-type Caco-2 cells treated with EPA exhibited increased cetuximab response rates, but these response rates were reduced in the BRAF-mutant cells. In conclusion, upregulation of miR-378 induced by EPA may result in the significant restoration of sensitivity to cetuximab in the KRAS-mutant cells. The present data will contribute to a notable potential therapeutic solution for future clinical CRC treatments.

Lauric acid can improve the sensitization of Cetuximab in KRAS/BRAF mutated colorectal cancer cells by retrievable microRNA-378 expression.

EGFR-inhibitor (Cetuximab) is one of the main targeted drugs used for metastatic colorectal carcinoma (CRC). The benefit from Cetuximab appears to be limited to a subtype of patients, not for the patients with tumors harboring mutated BRAF or KRAS genes; unfortunately, it accounts for ~40-50% of CRC cases. Previous studies have connected higher expression levels of miR-378 to be commonly presented in patients without BRAF or KRAS mutants than in mutated CRCs. The microRNA-378 (miR-378) is coexpressed with PGC-1ß and can be easily induced by fatty acid, for example lauric acid. Therefore, we hypothesized that elevation of miR-378 expression in mutated CRCs may stimulate the cell response to Cetuximab. Herein, seven CRC cell lines with confirmed mutation status were involved in two parallel experiments; directly in vitro transfected miR-378 mimics, and using lauric acid to indirectly induce the level of miR-378 in cells. After the increase of miR-378 in cells by either direct or indirect approaches, sensitivity to Cetuximab was restored in all BRAF mutants (p-value <0.0001-0.0003), and half of KRAS mutants CRC (p-value 0.039-0.007). Further evidence was gained by decreasing expression of MEK and ERK2 proteins after transfection with miR-378; it was similar to the indirect induction by lauric acid approach. In conclusion, the present study demonstrated that lauric acid may efficiently induce miR-378 expression in CRC mutants, and both BRAF and a subtype of KRAS mutants presented significantly improved sensitivity to Cetuximab. Notably, BRAF mutants could even be inhibited in cell proliferation after elevated concentration of miR-378 in cells without combining with targeted therapy. This new approach may shed new light on BRAF or KRAS mutation in CRC patients for clinical trial, since lauric acid may easily be obtain from natural food, and it is supposed to be harmless to the cardiovascular system.