METTL14 suppresses cancer stem cell phenotype of colorectal cancer via regulating of ß-catenin/NANOG.

Cancer stem cell (CSC) characteristic contributes to tumor malignancy and progression. The role of N6-methyladenosine (m6A) modification in CSC characteristic is largely unknown. In this study, we found that m6A methyltransferase METTL14 was downregulated in colorectal cancer (CRC) and negatively correlated with the poor prognosis of CRC patients. Overexpression of METTL14 inhibited CSC characteristic, while knockdown of METTL14 promoted this characteristic. Through screening, NANOG was identified as the downstream of METTL14. Mechanically, we demonstrated that METTL14 inhibited cancer stem cell characteristic by regulating ß-catenin. Collectively, our findings suggested that METTL16/ß-catenin /NANOG axis might be promising therapeutic targets for CRC.

Co-expression of CD24 and Hsp70 as a prognostic biomarker for lung cancer.

Lung cancer is one of the most common malignant neoplasms worldwide. CD24 is a marker of tumor stem cells that plays an important role in tumorigenesis. Hsp70 is an important molecular chaperone. However, the co-expression and interaction of CD24 and Hsp70, as well as the significance for the prognosis of lung cancer are still unclear. The expression levels of CD24 and Hsp70 were detected by immunohistochemistry and their correlation was analyzed. The expression levels of CD24 mRNA and protein were examined using qRT-PCR and western blotting in SPCA1, A549, H1975, and H1650 cell lines. A CD24-overexpressing cell model was established. The interaction between CD24 and Hsp70 was verified by co-immunoprecipitation and western blotting. CD24 and Hsp70 expression were significantly higher in lung cancer tissues than in adjacent tissues (CD24: p=0.008; Hsp70: p<0.001). CD24 protein expression showed a positive correlation with lymph node metastasis, TNM stage, and vascular cancer thrombus. Hsp70 protein expression showed a positive correlation with differentiation, lymph node metastasis, and TNM stage. CD24 and Hsp70 high expression were also correlated with poor survival. The positive co-expression rate of CD24 and Hsp70 in lung cancer tissues was 52.7% (49/93). CD24 and Hsp70 expression in lung cancer were positively correlated (r=0.368, p<0.001), and co-immunoprecipitation was verified that both endogenous and exogenous CD24 co-precipitated with Hsp70 directly or indirectly. When Hsp70 inhibitor VER15508 was added to A549 cells, Hsp70 and CD24 protein expression were significantly decreased. The present study demonstrated that CD24 and Hsp70 were highly expressed in lung cancer tissues, and associated with invasion, metastasis, and poor survival. Hsp70 may regulate CD24 expression. Co-expression of CD24 and Hsp70 may be a prognostic biomarker for lung cancer.

Long-term follow-up of the genital organs and eye lenses in three cases of acute radiation sickness from a 60Co radiation accident in China.

A follow-up study aimed primarily at investigating late radiation effects on the genital organs and eye lenses was performed between 1999 and 2010 on three individuals who suffered from acute radiation sickness in China. The examination included a medical history, a physical examination, ultrasonography, laboratory analysis, and an ophthalmologic examination. In Case 1, amenorrhea occurred after exposure to a Co source. The uterus and ovaries were significantly narrowed in the second year following exposure. The estradiol level decreased significantly during the first 3 y; progesterone was lowest in the second year; and levels of follicle-stimulating hormone and luteinizing hormone increased, especially in the first year. The lenses in both eyes appeared opaque 6 mo after the exposure, resulting in a gradual deterioration in visual acuity. In Case 2 (8 y old), the levels of testosterone and estradiol were normal. In Case 3, the levels of testosterone and estradiol were also normal, but the sperm count was 0 from 6 mo to 1 y, and the proportion of abnormal sperm was increased from 3-5 y after the accident. The lenses in Case 3 also began to turn opaque in the ninth year after the accident. In Case 1, the ovarian function was reduced, leading to amenorrhea and early menopause. In Case 3, the sperm count was reduced and the number of abnormal sperm was increased due to testicular damage by radiation. Radiation-induced cataracts occurred in both Case 1 and Case 3.

[Dose-effect relationship between premature chromosome and irradiation dose].

OBJECTIVE: To explore the dose-effect relationship between premature chromosome condensation induced by Calyculin A and irradiation dose. METHODS: The human peripheral blood was irradiated by (137)Cs gamma radial. The irradiation dose included 0, 0.5, 1.0, 2.0, 3.0, 4.0, 5.0 Gy. The premature chromosome condensation induced by Calyculin A was observed, and dyed by centromeric banding. RESULTS: There was the quadratic relation between the total aberration, fragment, dicentric+centric ring (dic+r) ration and irradiation dose. CONCLUSION: Premature chromosome condensation induced by Calyculin A can be used as a biodosimetry.