Expression of fatty acid synthase and its association with HER2 in invasive ductal carcinoma of breast / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the expression of fatty acid synthase (FAS) in adenosis, atypical ductal epithelial hyperplasia, ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) of breast, and the correlation of FAS expression with HER2 gene amplification in IDC.</p><p><b>METHODS</b>Immunohistochemical EnVision method staining for FAS was performed in 100 cases of breast lesions and 10 normal breast tissues. HER2 gene amplification was detected with FISH in 60 cases of IDC.</p><p><b>RESULTS</b>The cohort included 10 cases of adenosis, 10 atypical ductal epithelial hyperplasia, 20 DCIS (8 high-grade, 9 intermediated-grade and 3 low-grade), and 60 cases of IDC (5 grade 1, 40 grade 2 and 15 grade 3). FAS expression was negative in all 10 normal breast tissues; in the 10 cases of adenosis, strongly positive FAS expression was detected in one case, positive in 2, weakly positive in 4, and negative in 3; in the 10 cases of atypical ductal epithelial hyperplasia, FAS immunohistochemistry showed that 1 was strongly positive, 4 positive, 4 weakly positive, and 1 negative; in the 20 cases of DCIS, FAS immunostaining showed that 12 were strongly positive, 5 positive, 1 weakly positive, and 2 negative; FAS expression showed a clear increasing trend from normal breast tissue, atypical ductal epithelial hyperplasia to DCIS (χ(2) = 42.02, P < 0.01). Likewise, the increasing trend was also demonstrated from adenosis to DCIS (χ(2) = 34.69, P < 0.01). There was also a positive correlation between FAS expression and extent of lesion among normal breast tissue, adenosis, atypical ductal epithelial hyperplasia and DCIS (χ(2) = 86.02, P < 0.01; r = 0.568, P < 0.01). FAS expression was not correlated with the grade of DCIS (χ(2) = 9.12, P = 0.16). In the five cases of grade 1 IDC, FAS immunostaining showed that 4 cases were strongly positive and 1 positive; in the 40 cases of grade 2 IDC, FAS immunostaining showed that 27 strongly positive, 12 positive, and 1 negative; in the 15 cases of grade 3 IDC, FAS immunostaining showed that 6 were strongly positive, 5 positive, 3 weakly positive, and 1 negative; FAS expression was stronger and more extensive in DCIS, IDC grades 1 and 2 than that in other groups. However, FAS expression was weaker in the IDC grade 3 (χ(2) = 11.26, P = 0.01). The positive expression rate of FAS in IDC was generally higher than that in benign breast lesions (χ(2) = 47.19, P < 0.01). In the 60 cases of IDC, FISH showed HER2 gene amplification in 22 cases, but not in the remaining 38 cases. FAS expression in IDC was highly correlated with HER2 gene amplification (r = 0.44, P < 0.01). The expression of FAS had significant correlation with status of ER and PR and tumor size (P < 0.05). There was no significant correlation with age, immunohistochemical HER2 expression, lymph node metastasis and clinical stage (P > 0.05).</p><p><b>CONCLUSIONS</b>FAS may be closely related to the carcinogenesis of breast IDC. FAS expression is closely associated with HER2 gene amplification in IDC.</p>

Effect of hypoxia on the chemotherapeutic sensitivity of human ovarian cancer cells to paclitaxel and its mechanism / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the effect of hypoxia and hypoxia-inducible factor-1alpha (HIF-1alpha) on the expression of multidrug resistance gene-1 (mdr-1) and its coded p-glyeoprotein (P-gp) as well as the chemotherapeutic sensitivity of human ovarian cancer cells to paclitaxel and its mechanism.</p><p><b>METHODS</b>The mRNA and protein levels of HIF-1alpha, mdr-1 and p-gp were studied by immunocytochemistry, semiquantitative reverse transcription-ploymerase chain reaction (RT-PCR) and Western blot analysis in human ovarian cancer cells (A2780) in 5% CO2 + 1% O2 hypoxic culture and 21% O2 normoxic culture, respectively. Methyl thiazolyl tetrazolium (MIT) was used to evaluate the chemotherapeutic sensitivity of A2780 cells to paclitaxel by inhibition rate. RNA interference technique was used and small hairpin RNAs (shRNAs) eukaryotic expression vector targeting HIF-1alpha was constructed as pSiHIF-1alpha, and transfected into A2780 cells. RT-PCR and Western blot were used to detect gene silencing effect on HIF-1alpha, the expressions of mdr-1 and p-gp. The inhibition rate was observed after HIF-1alpha gene silence.</p><p><b>RESULTS</b>HIF-1alpha at both mRNA and protein levels was induced significantly under hypoxia. The HIF-1alpha expression at mRNA level was oxygen gradient-independent, while HIF-1alpha expression at protein level was oxygen gradient-dependent. The inhibition rate of paclitaxel to hypoxic A2780 cells in 5% CO2 + 1% O2 was significantly lower than that in normoxic A2780 cells (P <0.05). The shRNAs plasmid targeting HIF-1alpha was constructed successfully and HIF-1alpha gene was silenced in A2780 cells efficiently followed by mdr-1 and p-gp down-regulation. The inhibition rate was greatly increased in hypoxic A2780/siHIF-1alpha cells.</p><p><b>CONCLUSION</b>Hypoxia can decrease the chemotherapeutic sensitivity of human ovarian cancer A2780 cells to paclitaxel through HIF-1alpha regulating the expression of mdr-1 and p-gp.</p>

Cigarette smoke extract inhibits the proliferation of alveolar epithelial cells and induces apoptosis / 生理学报

Cigarette smoke extract (CSE) contains abundant oxidants and free radicals. Oxidative stress caused by cigarette smoking results in the destruction of the alveolar cell walls and emphysema. However, there exists discrepancy about how CSE works in the process. In the present study, we observed the effect of CSE on the cell growth of type II alveolar epithelial cell-derived A549 cell line, and provided molecular understanding of this effect. The MTT assay results showed that CSE decreased the cell viability of A549 cells in a dose- and time-dependent manner, and cell cycle was arrested in G(1)/S phase. Furthermore, CSE-induced apoptosis of A549 cells was verified by Hoechst 33258 staining, electron microscopy in morphology, and the appearance of DNA fragmentation and annexin V-FITC/propidium iodide (PI) staining assay at molecular level. It was found that CSE treatment resulted in the upregulation of Fas/APO-1 receptor and activation of caspase-3. CSE also initiated accumulation of intracellular reactive oxygen species, which was detected by laser confocal microscopy. Taken together, CSE could inhibit the cell growth and induce apoptosis of A549 cells through Fas receptor pathway. Oxidative stress caused by CSE may be the radical factor leading to apoptosis as well as cell growth inhibition in alveolar epithelial cells.