Although JC virus (JCV), a human polyomavirus, has been detected in colon cancers, the association between JCV and colon cancer remains controversial. In Taiwan, the prevalence of JCV infection in colon cancer patients has not been reported. Thus, the purpose of this study was to investigate JCV infection in colon cancers in Taiwan. Formalin-fixed, paraffin-embedded tissues from 22 colon cancer patients were examined in this study. Nested PCR was performed to detect viral genomic DNA. The product of the nested PCR flanking the JCV regulatory region was sequenced further. Viral large tumor protein, LT, and late capsid protein, VP1, were examined by immunohistochemistry (IHC). Nested PCR revealed JCV genomic DNA in 86.4% (19/22) of the colon cancer tissue samples. Both rearranged and archetypal genotypes of JCV were identified. Expression of JCV LT was positive in 63.6% (14/22) of the examined colon cancer tissue samples but not in any adjacent normal region. Expression of viral capsid protein VP1 was not detected in any of the tissues examined. The current study demonstrates that JCV genomic DNA was present in the examined colon cancer tissues. The genotypes of JCV in colon cancer tissues were also identified. Expression of viral early protein but not structural capsid protein was detected in the examined colon cancer tissues. Furthermore, a high prevalence of JCV infection in colon cancer tissues in Taiwan was also demonstrated.

Edited by Ned Mantei Keywords:Induced pluripotent stem cell Induced neural stem/progenitor cell Cyclin D Cell cycle a b s t r a c t A short G1 phase is a characteristic feature of the cell cycle structure of pluripotent cells, and is reestablished during Yamanaka factor-mediated pluripotent reprogramming. How cell cycle control is adjusted to meet the requirements of pluripotent cell fate commitment during reprogramming is less well understood. Elevated levels of cyclin D1 were initially found to impair pluripotency maintenance. The current work further identified Cyclin D1 to be capable of transcriptionally upregulating Pax6, which promoted reprogramming cells to commit to a neural progenitor fate rather than a pluripotent cell fate. These findings explain the importance of reestablishment of G1-phase restriction in pluripotent reprogramming.

a b s t r a c tTargeted inhibition of multidrug ABCG2 transporter is believed to improve cancer therapeutics. However, the consequences of ABCG2 inhibition have not been systematically evaluated since ABCG2 is expressed in several organs including the liver. Here, we demonstrate that ABCG2-deficient hepatocytes have increased amounts of fragmental mitochondria accompanied by disruption of mitochondrial dynamics and functions. This disruption was due to ABCG2 knockout elevating intracellular protoporphyrin IX, which led to upregulation of DRP-1-mediated mitochondrial fission. The finding that ABCG2 deficiency can generate dysfunctional mitochondria in hepatocytes raises concerns regarding the systematic use of ABCG2 inhibitor in cancer patients.

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An important safety concern in the use of human pluripotent stem cells (hPSCs) is tumorigenic risk, because these cells can form teratomas after an in vivo injection at ectopic sites. Several thousands of undifferentiated hPSCs are sufficient to induce teratomas in a mouse model. Thus, it is critical to remove all residue-undifferentiated hPSCs that have teratoma potential before the clinical application of hPSC-derived cells. In this study, our data demonstrated the cytotoxic effects of cardiac glycosides, such as digoxin, lanatoside C, bufalin, and proscillaridin A, in human embryonic stem cells (hESCs). This phenomenon was not observed in human bone marrow mesenchymal stem cells (hBMMSCs). Most importantly, digoxin and lanatoside C did not affect the stem cells’ differentiation ability. Consistently, the viability of the hESC-derived MSCs, neurons, and endothelium cells was not affected by the digoxin and lanatoside C treatment. Furthermore, the in vivo experiments demonstrated that digoxin and lanatoside C prevented teratoma formation. To the best of our knowledge, this study is the first to describe the cytotoxicity and tumor prevention effects of cardiac glycosides in hESCs. Digoxin and lanatoside C are also the first FDA-approved drugs that demonstrated cytotoxicity in undifferentiated hESCs.

Epithelial ovarian cancer (OC) is a highly heterogeneous and malignant female cancer with an overall low survival rate. Mutations in p53 are prevalent in the major OC histotype, high-grade serous ovarian carcinoma (HGSOC), while p53 mutations are much less frequent in other OC subtypes, particularly in ovarian clear cell carcinoma (OCCC). Advanced stage OCCC with wildtype (WT) p53 has a worse prognosis and increased drug resistance, metastasis, and recurrence than HGSOC. The mechanisms responsible for driving the aggressiveness of WT p53-expressing OC remain poorly understood. Here, we found that upregulation of MEX3A, a dual-function protein containing a RING finger domain and an RNA binding domain, was critical for tumorigenesis in WT p53-expressing OC. MEX3A overexpression enhanced the growth and clonogenicity of OCCC cell lines. In contrast, depletion of MEX3A in OCCC cells, as well as ovarian teratocarcinoma cells, reduced cell survival and proliferative ability. MEX3A depletion also inhibited tumor growth and prolonged survival in orthotopic xenograft models. MEX3A depletion did not alter p53 mRNA level but did increase p53 protein stability. MEX3A-mediated p53 protein degradation was crucial to suppress ferroptosis and enhance tumorigenesis. Consistently, p53 knockdown reversed the effects of MEX3A depletion. Together, our observations identified MEX3A as an important oncogenic factor promoting tumorigenesis in OC cells expressing WT p53.

Patients with type 1 diabetes mellitus are associated with impairment in vitamin A metabolism. This study evaluated whether treatment with retinoic acid, the biologically active metabolite of vitamin A, can ameliorate diabetes. All-trans retinoic acid (atRA) was used to treat streptozotocin (STZ)-induced diabetic mice which revealed atRA administration ameliorated blood glucose levels of diabetic mice. This hyperglycemic amelioration was accompanied by an increase in the amount of β cells co-expressed Pdx1 and insulin and by restoration of the vascular laminin expression. The atRA-induced production of vascular endothelial growth factor-A from the pancreatic islets was possibly the key factor that mediated the restoration of islet vascularity and recovery of β-cell mass. Furthermore, the combination of islet transplantation and atRA administration significantly rescued hyperglycemia in diabetic mice. These findings suggest that vitamin A derivatives can potentially be used as a supplementary treatment to improve diabetes management and glycemic control.