Overexpression of NAT10 induced platinum drugs resistance in breast cancer cell / 中华肿瘤杂志

Objective: To observe the platinum drugs resistance effect of N-acetyltransferase 10 (NAT10) overexpression in breast cancer cell line and elucidate the underlining mechanisms. Methods: The experiment was divided into wild-type (MCF-7 wild-type cells without any treatment) group, NAT10 overexpression group (H-NAT10 plasmid transfected into MCF-7 cells) and NAT10 knockdown group (SH-NAT10 plasmid transfected into MCF-7 cells). The invasion was detected by Transwell array, the interaction between NAT10 and PARP1 was detected by co-immunoprecipitation. The impact of NAT10 overexpression or knockdown on the acetylation level of PARP1 and its half-life was also determined. Immunostaining and IP array were used to detect the recruitment of DNA damage repair protein by acetylated PARP1. Flow cytometry was used to detect the cell apoptosis. Results: Transwell invasion assay showed that the number of cell invasion was 483.00±46.90 in the NAT10 overexpression group, 469.00±40.50 in the NAT10 knockdown group, and 445.00±35.50 in the MCF-7 wild-type cells, and the differences were not statistically significant (P>0.05). In the presence of 10 μmol/L oxaliplatin, the number of cell invasion was 502.00±45.60 in the NAT10 overexpression group and 105.00±20.50 in the NAT10 knockdown group, both statistically significant (P<0.05) compared with 219.00±31.50 in wild-type cells. In the presence of 10 μmol/L oxaliplatin, NAT10 overexpression enhanced the binding of PARP1 to NAT10 compared with wild-type cells, whereas the use of the NAT10 inhibitor Remodelin inhibited the mutual binding of the two. Overexpression of NAT10 induced PARP1 acetylation followed by increased PARP1 binding to XRCC1, and knockdown of NAT10 expression reduced PARP1 binding to XRCC1. Overexpression of NAT10 enhanced PARP1 binding to LIG3, while knockdown of NAT10 expression decreased PARP1 binding to LIG3. In 10 μmol/L oxaliplatin-treated cells, the γH2AX expression level was 0.38±0.02 in NAT10 overexpressing cells and 1.36±0.15 in NAT10 knockdown cells, both statistically significant (P<0.05) compared with 1.00±0.00 in wild-type cells. In 10 μmol/L oxaliplatin treated cells, the apoptosis rate was (6.54±0.68)% in the NAT10 overexpression group and (12.98±2.54)% in the NAT10 knockdown group, both of which were statistically significant (P<0.05) compared with (9.67±0.37)% in wild-type cells. Conclusion: NAT10 overexpression enhances the binding of NAT10 to PARP1 and promotes the acetylation of PARP1, which in turn prolongs the half-life of PARP1, thus enhancing PARP1 recruitment of DNA damage repair related proteins to the damage sites, promoting DNA damage repair and ultimately the survival of breast cancer cells.

Clinical characteristics comparison between triple-negative and non-triple-negative breast cancer / 中华外科杂志

<p><b>OBJECTIVE</b>To compare the clinical characteristics of triple-negative (TN) breast cancer and non-triple-negative (NTN) breast cancer, enrich the information of TN patients, and provide evidences for individualized combined treatment.</p><p><b>METHODS</b>The data of 408 cases received operation in the year of 2002 was enrolled in this study. TN patients were confirmed according to the immunohistochemical (IHC) test of estrogen receptor (ER), progesterone receptor (PR) and HER-2/neu. The clinical characteristics, recurrence, metastasis and survival were compared between the two groups.</p><p><b>RESULTS</b>Seventy-seven patients (18.9%) were confirmed TN cases. The median follow-up was 64 months (range, 3-79 months). Of all the cases, 58 occurred local recurrence or metastasis and 51 died, it was 19 and 12 in TN group. Compared with the NTN group, the TN patient tended to be younger and the tumor mass larger (P=0.015 and 0.011). However, axillary lymph nodes metastasis occurred more often in NTN patients than in TN patients (P=0.001). The rate of local recurrence and metastasis in TN group was significantly higher than in NTN group (P=0.005 and 0.025), and TN cases were more likely to develop lung metastasis than NTN patients (P<0.01). The 3-year and 5-year overall survival rate in TN group were significantly lower than in NTN group (86.4% vs. 93.4%, P=0.0205; 77.7% vs. 87.9%, P=0.0215). The 3-year and 5-year disease-free survival rate in TN group were also significantly lower than in NTN group (78.4% vs. 92.4%, P=0.0038; 72.8% vs. 85.8%, P=0.0041). Tumor size, lymph node status and triple-negative were the most important factors influencing the prognosis on multivariate Cox regression analysis.</p><p><b>CONCLUSIONS</b>TN breast cancer haa some specific clinical characteristics. The prognosis of TN patients is worse than that of NTN patients. Further study is needed to find individualized treatment for TN breast cancer patients.</p>

Clinical characteristics and survival in the operable breast cancer patients with different molecular subtypes / 中华肿瘤杂志

<p><b>OBJECTIVE</b>According to the immunohistochemical (IHC) test of ER, PR and HER-2, breast cancer can be divided into 4 different molecular subtypes: Luminal A subtype (ER or PR positive and HER-2 negative), Luminal B subtype (ER or PR positive and HER-2 positive), HER-2 subtype (ER and PR negative, HER-2 positive) and Basal-like subtype (ER, PR and HER-2 negative). This study was to analyze the clinical features of different breast cancer subtypes, and try to find the evidence of combined and individualized treatment for patients with breast cancer.</p><p><b>METHODS</b>The data of 408 surgically treated breast cancer patients in the Cancer Hospital of Chinese Academy of Medical Sciences from January 1, 2002 to December 31, 2002 were collected and retrospectively analyzed. The clinicopathological features and recurrence, metastasis as well as survival of these four subtypes were compared.</p><p><b>RESULTS</b>Of the 408 cases, Luminal A subtype accounted for 60.8% (248/408), Luminal B subtype 7.8% (32/408), HER-2 subtype 12.5% (51/408), and Basal-like subtype 18.9% (77/408). Basal-like subtype had less lymph node metastases than other subtypes (P<0.05). HER-2 subtypes consisted of less patients aged 45 years or younger than other subtypes (P<0.05). Luminal B subtype contained less advanced cases than other subtypes (P<0.01). By August 2008, the median time of follow-up was 64 months (range, 3-79 months). Fifty-eight cases presented local recurrence or metastasis, and 51 of them died of the disease. The 5-year overall survival rates (OS) for patients with Luminal A, Luminal B, Basal-like and HER-2 subtype were 89.83%, 86.15%, 79.85% and 86.70% , respectively. The 5-year disease-free survival (DFS) rates of the four subtypes were 83.52%, 68.88%, 71.66% and 75.83%, respectively. The rate of local recurrence or metastasis in Luminal A subtype was significantly lower than that in Luminal B and Basal-like subtypes (P<0.05). The DFS time in Luminal B subtype was shorter than that in Luminal A subtype (P=0.0481). The OS and DFS time in Basal-like subtype were all shorter than that in Luminal A subtype (P=0.0077 and P=0.0306, respectively).</p><p><b>CONCLUSION</b>The distribution of each subtype in Chinese breast cancer patients is similar to that in European and American breast cancer patients. Luminal A is the most common subtype in Chinese breast cancer patients, and has a good prognosis. While Basal-like and Luminal B subtype have a poor prognosis.</p>

Clinicopathologic analysis of primary pure squamous cell carcinoma of the breast / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To analyze the clinicopathologic characteristics and treatment method for primary pure squamous cell carcinoma of the breast.</p><p><b>METHODS</b>Twelve patients with primary squamous cell carcinoma of the breast pathologically confirmed were retrospectively reviewed. The clinical characteristics, diagnosis, treatment and prognosis were analyzed.</p><p><b>RESULTS</b>All 12 patients were women with median age of 50 years (44-76 years). The patients all presented a single mass in the breast on presentation. The diameter ranged from 2.5 cm to 10.0 cm in diameter. All of the patients had undergone surgical resection. There were 6 cases in stage IIa, 2 in IIb, 2 in IIIa and 2 in IIIb according to the TNM staging system of AJCC and UICC. Ten of the 12 cases were followed-up from 4 months to 189 months.</p><p><b>CONCLUSION</b>Primary squamous cell carcinoma of the breast is often in need of diagnosis by exclusion, but can be initially confirmed by fine needle aspiration. Presently, no standard therapy can be recommended in practice. The prognosis is controversial.</p>