Author Correction: Impact of hormone receptor status and distant recurrence-free interval on survival benefits from trastuzumab in HER2-positive metastatic breast cancer.

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Mitochondrial division inhibitor 1 protects cortical neurons from excitotoxicity: a mechanistic pathway.

Mitochondrial division inhibitor 1 (Mdivi-1) is a selective cell-permeable inhibitor of dynamin-related protein-1 (Drp1) and mitochondrial division. To investigate the effect of Mdivi-1 on cells treated with glutamate, cerebral cortex neurons isolated from neonatal rats were treated with 10 mM glutamate for 24 hours. Normal cultured cells and dimethyl sulfoxide-cultured cells were considered as controls. Apoptotic cells were detected by flow cytometry. Changes in mitochondrial morphology were examined by electron microscopy. Drp1, Bax, and caspase-3 expression was evaluated by western blot assays and immunocytochemistry. Mitochondrial membrane potential was detected using the JC-1 probe. Twenty-four hours after 10 mM glutamate treatment, Drp1, Bax and caspase-3 expression was upregulated, Drp1 and Bax were translocated to mitochondria, mitochondrial membrane potential was decreased and the rate of apoptosis was increased. These effects were inhibited by treatment with 50 µM Mdivi-1 for 2 hours. This finding indicates that Mdivi-1 is a candidate neuroprotective drug that can potentially mitigate against neuronal injury caused by glutamate-induced excitotoxicity.

Antigenicity of tissues and organs from GGTA1/CMAH/ß4GalNT2 triple gene knockout pigs.

Clinical xenotransplantations have been hampered by human preformed antibody-mediated damage of the xenografts. To overcome biological incompatibility between pigs and humans, one strategy is to remove the major antigens [Gal, Neu5Gc, and Sd(a)] present on pig cells and tissues. Triple gene (GGTA1, CMAH, and ß 4GalNT2) knockout (TKO) pigs were produced in our laboratory by CRISPR-Cas9 targeting. To investigate the antigenicity reduction in the TKO pigs, the expression levels of these three xenoantigens in the cornea, heart, liver, spleen, lung, kidney, and pancreas tissues were examined. The level of human IgG/IgM binding to those tissues was also investigated, with wildtype pig tissues as control. The results showed that αGal, Neu5Gc, and Sd(a) were markedly positive in all the examined tissues in wildtype pigs but barely detected in TKO pigs. Compared to wildtype pigs, the liver, spleen, and pancreas of TKO pigs showed comparable levels of human IgG and IgM binding, whereas corneas, heart, lung, and kidney of TKO pigs exhibited significantly reduced human IgG and IgM binding. These results indicate that the antigenicity of TKO pig is significantly reduced and the remaining xenoantigens on porcine tissues can be eliminated via a gene targeting approach.

Generation of tryptophan hydroxylase 2 gene knockout pigs by CRISPR/Cas9-mediated gene targeting.

Unbalanced brain serotonin (5-HT) levels have implications in various behavioral abnormalities and neuropsychiatric disorders. The biosynthesis of neuronal 5-HT is regulated by the rate-limiting enzyme, tryptophan hydroxylase-2 (TPH2). In the present study, the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated (Cas) system was used to target theTph2 gene in Bama mini pig fetal fibroblasts. It was found that CRISPR/Cas9 targeting efficiency could be as high as 61.5%, and the biallelic mutation efficiency reached at 38.5%. The biallelic modified colonies were used as donors for somatic cell nuclear transfer (SCNT) and 10Tph2 targeted piglets were successfully generated. These Tph2 KO piglets were viable and appeared normal at the birth. However, their central 5-HT levels were dramatically reduced, and their survival and growth rates were impaired before weaning. TheseTph2 KO pigs are valuable large-animal models for studies of 5-HT deficiency induced behavior abnomality.

The lymph node ratio as an independent prognostic factor for node-positive triple-negative breast cancer.

BACKGROUND: We aimed to evaluate the prognostic value of the lymph node ratio (LNR) in patients with axillary lymph node-positive triple-negative breast cancer (TNBC). METHODS: The prognostic efficacy was investigated in the first cohort from the Surveillance, Epidemiology, and End Results (SEER) dataset (n=4114) and was further validated in an independent cohort from Fudan University Shanghai Cancer Center (n=417). Patients were classified into low-, medium- and high-risk LNR groups. RESULTS: Multivariate analysis revealed that the LNR was an independent predictor of overall survival (hazard ratio (HR) for high-risk LNR: 3.24; 95% confidence interval (CI): 2.56 to 4.09) and breast cancer-specific survival (HR for high-risk LNR: 3.57; 95% CI: 2.76 to 4.62) in the SEER population and also for disease-free survival (HR for high-risk LNR: 4.29; 95% CI: 2.24-8.21) in the validation population. Subgroup analysis revealed that patient classification according to the LNR could discriminate among groups of patients with different survival rates based on pathological nodal (pN) staging. CONCLUSION: The LNR shows potential for use as an additional prognostic factor for TNBC patients with positive lymph node involvement. Considering the heterogeneity of TNBC, use of the LNR might allow for optimization of the pN staging system and should be considered when making treatment decisions.

Impact of hormone receptor status and distant recurrence-free interval on survival benefits from trastuzumab in HER2-positive metastatic breast cancer.

We sought to investigate the impact of hormone receptor (HR) status and distant recurrence-free interval (DRFI) on the degree of overall survival (OS) benefit from palliative trastuzumab-containing treatment in HER2-positive metastatic breast cancer (MBC). Here, we retrospectively identified 588 eligible HER2-positive patients with postoperative distant recurrence. DRFI of HR+HER2+ MBC patients (median: 30.7 months, IQR: 18.5-45.9, P < 0.001) was significant longer compared with HR-HER2+ patients. Patients were categorized into four subgroups based on HR status and palliative trastuzumab (trast+) received. The most superior outcome was observed in the HR+HER2+trast+ subgroup, with a median OS of 48.3 months. Moreover, DRFI > 24 months is an independent favourable prognostic factor for both HR-HER2+ patients (Hazard Ratio (HzR) = 0.55, 95% CI: 0.39-0.76, P < 0.001) and HR+HER2+ patients (HzR = 0.45, 95% CI: 0.32-0.64, P < 0.001). Upon further analysis of the interaction between trastuzumab and DRFI, the degree of trastuzumab benefits in HR-HER2+ MBC patients remained basically unchanged regardless of DRFI length. Unlikely, the degree in HR+HER2+ MBC patients decreased gradually along with DRFI extending, indicating that trastuzumab failed to translate into an OS benefit for late recurrent (DRFI > 5years) HR+HER2+ MBC patients.

Luminal B subtype: a key factor for the worse prognosis of young breast cancer patients in China.

BACKGROUND: The prognoses of young breast cancer patients are poor. The purpose of this study is to evaluate the different characteristics and prognoses among different subtypes of young breast cancer patients. METHODS: The study included 1360 patients <40 years-old (y) and 3110 patients 40-50y with operable breast cancer in Shanghai Cancer Center, Fudan University. The characteristics, overall survival (OS) and disease-free survival (DFS) were compared. RESULTS: The median follow-up was 54.1 months. More grade III tumors and more lymph-vascular invasions (P < 0.01) were presented in <40y group when compared with 40-50y group. More patients <40y presented with Luminal B (25.3% vs. 17.5%, P < 0.01) and triple negative (16.7% vs. 13.4%, P < 0.05) breast cancer while fewer had Luminal A tumor (48.5% vs. 59.2%, P < 0.01). Younger patients with tumors of both Luminal A and Luminal B types were at increased risk for worse DFS (P = 0.03, HR = 1.69, 95% CI = 1.05-2.72; P < 0.01, HR = 3.61, 95% CI = 2.50-5.22) when compared with the older patients. Patients <40y with Luminal B tumor had a two point five fold higher risk of death compared with older counterparts (P < 0.01, HR = 2.54, 95% CI = 1.35-4.79), however, a worse overall survival rate was not observed in the younger women with Luminal A breast cancer (P > 0.05). In multivariate analysis, Luminal B subtype was also a strong predictor of disease relapse (HR = 1.09, 95% CI = 1.01 to 1.19, P < 0.01) in younger patients with Luminal subtype tumors. CONCLUSION: Characteristics of breast cancer suggested a more aggressive biology in Chinese patients with breast cancer diagnosed at young age. Luminal B subtype may have a negative effect on the prognosis of young patients in China which should be validated further.