Dose-dependent expression changes of early response genes to ionizing radiation in human lymphoblastoid cells.

The sensitivity of cancer cells as well as normal cells in response to ionizing radiation (IR) is believed to be associated with the early inducible expression of specific genes. Using cDNA microarray technology, here we explored and compared the global transcriptional changes in human lymphoblastoid AHH-1 cells irradiated with 0.05-, 0.2-, 0.5-, 2.0- and 10-Gy doses of gamma-rays 4 h after exposure. A dose as low as 0.05 Gy was efficient in inducing a transcriptional response including the up-regulation of 25 genes, some of which are involved in signal transduction pathways, e.g. BMPR2, GPR124, MAPK8IP2 and AGGF1, and the down-regulation of 18 genes. Expression of some genes was altered only at a specific dose. Most importantly, we discovered a number of radiation-response genes, e.g. DNA repair gene XPC, tumor protein p53 inducible protein 3 gene (TP53I3), immediate early response 5 gene, whose transcriptional levels were increased or depressed by IR in a dose-dependent trend within the dose range 0.05-10 Gy. The dose-dependent induced expression of TP53I3 and XPC was confirmed by Northern blot analyses. Using quantitative real-time PCR, we further confirmed that XPC gene induction was dose dependent as well as time dependent, reaching a peak 4 h post-2 Gy and 10 h post-0.05 Gy. The maximum induced expression level of the XPC gene was higher after 2 Gy (3.2-fold) than 0.05 Gy (1.93-fold). The identification of these radiation-inducible genes, especially those exhibiting a dose-dependent response, not only expands our knowledge of the mechanisms underlying the diverse biological effects induced by IR, but provides candidates for developing novel biomarkers of radiation injury.

[Impact of hepatitis B virus infection on liver function after hematopoietic stem cell transplantation].

To analyze the impact of hepatitis B virus (HBV) infection on liver function of patients after hematopoietic stem cell transplantation (HSCT), the transplantation outcome of 48 patients infected with HBV prior to transplantation among 185 patients received HSCT was investigated retrospectively. The results showed that during a follow-up for 6 months after HSCT, the alanine aminotransferase (ALT) peak average values of the patients with HBsAg(+), HBsAb(+) and control groups were (281.6 ± 414.6), (95.4 ± 79.9) and (65.1 ± 44.2) U/L, respectively. The incidences of abnormal liver function of the patients with HBsAg(+), HBsAb(+) and control groups were 61.54%, 40.00% and 30.23% respectively. There were no significant differences between any two groups (P > 0.05). The lethality of those patients at late period after transplantation was not related to HBV infection. The hepatocirrhosis and hepatocarcinoma caused by HBV infection have not become major problems in long-term survivors. It is concluded that in HBsAg(+) patients received HSCT, the damage of liver function is more severe than control group, possibly increasing the development of abnormal liver function. The measures against the liver function damage should be taken. The prophylactic administration of ganciclovir for virus may be effective to prevent the activation of HBV.

[Expressions of RhoC, CD44v6 and ICAM-1 in human gastric cancer and its clinicopathological significance].

OBJECTIVE: To investigate the expressions of RhoC, CD44v6 and ICAM-1 in gastric cancer and their correlations. METHODS: SABC immunohistochemistry was used to detect the expressions of RhoC, CD44v6 and ICAM-1 in the specimens from 40 cases with gastric cancer. Their correlations were reviewed by clinicopathological data. RESULTS: The expression of RhoC, CD44v6 and ICAM-1 were not correlated with tumor differentiation and invasion depth (P> 0.05), but significantly correlated with lymph metastasis and pTNM stage (P< 0.05). There was a significant correlation between the expression of RhoC and the expression of CD44v6 or ICAM-1 (r=0.355, P=0.006; r=0.354, P=0.003) respectively. If RhoC was positive-expressed, and either of CD44v6 or ICAM-1 was positive-expressed, the sensitivity and the specificity for predicting the lymphatic metastasis was 93.75%, 62.5% respectively. CONCLUSIONS: The positive expressions of RhoC, CD44v6 and ICAM-1 are useful biological markers for predicting the metastatic potential of gastric cancer. The combined detection of three markers is a useful method for predicting lymphatic metastasis of gastric cancer.