Orthogonal sp3-Ge/B Bimetallic Modules: Enantioselective Construction and Enantiospecific Cross-Coupling.

In this study, a series of enantioenriched sp3-Ge/B bimetallic modules were successfully synthesized via an enantioselective copper-catalyzed hydroboration of carbagermatrane (Ge)-containing alkenes. Orthogonal cross-coupling selectivity under different Pd-catalyzed conditions was achieved in an enantiospecific manner. Notably, the chiral secondary Ge exhibited a remarkable transmetallation ability prior to primary or secondary Bpin. The effectiveness of this Ge/B bimetallic strategy was further demonstrated through the development of new functional small molecules with Aggregation-Induced Emission (AIE) and Circularly Polarized Luminescence (CPL) performance. This represents the first successful example of synthesis of enantioenriched alkylgermanium reagents that permit enantiospecific cross-coupling reactions.

Nomogram based on pretreatment hepatic and renal function indicators for survival prediction of locally advanced esophageal squamous cell carcinoma with treatment of neoadjuvant chemoradiotherapy plus surgery.

The parameters for survival prediction of esophageal squamous cell carcinoma (ESCC) patients treated with neoadjuvant chemoradiotherapy (NCRT) combined with surgery are unclear. Here, we aimed to construct a nomogram for survival prediction of ESCC patients treated with NCRT combined with surgery based on pretreatment serological hepatic and renal function tests. A total of 174 patients diagnosed as ESCC were enrolled as a training cohort from July 2007 to June 2019, and approximately 50% of the cases (n = 88) were randomly selected as an internal validation cohort. Univariate and multivariate Cox survival analyses were performed to identify independent prognostic factors to establish a nomogram. Predictive accuracy of the nomogram was evaluated by Harrell's concordance index (C-index) and calibration curve. ALT, ALP, TBA, TP, AST, TBIL and CREA were identified as independent prognostic factors and incorporated into the construction of the hepatic and renal function test nomogram (HRFTNomogram). The C-index of the HRFTNomogram for overall survival (OS) was 0.764 (95% CI 0.701-0.827) in the training cohort, which was higher than that of the TNM staging system (0.507 (95% CI 0.429-0.585), P < 0.001). The 5-year OS calibration curve of the training cohort demonstrated that the predictive accuracy of the HRFTNomogram was satisfactory. Moreover, patients in the high-risk group stratified by the HRFTNomogram had poorer 5-year OS than those in the low-risk group in the training cohort (27.4% vs. 80.3%, P < 0.001). Similar results were observed in the internal validation cohort. A novel HRFTNomogram might help predict the survival of locally advanced ESCC patients treated with NCRT followed by esophagectomy.

Prognostic value of L4 lymph node dissection during video-assisted thoracoscopic surgery in patients with left-sided non-small cell lung cancer: a single-center, retrospective cohort study.

Background: Lymph node dissection (LND) is crucial procedure during radical resection of non-small cell lung cancer (NSCLC), but the prognostic value of L4 LND remains elusive. To investigate the prognostic value of L4 LND in patients with left-side NSCLC who underwent video-assisted thoracoscopic surgery (VATS). Methods: Three hundred twelve patients who underwent VATS between Jan. 2007 and Dec. 2016 were reviewed. Of those, 119 underwent L4 LND (L4D+), whereas the other 193 patients did not (L4D-). The inclusion criteria were as follows: patients diagnosed with primary left-sided NSCLC who underwent VATS lobectomy combined with LND; patients subjected to R0 resection and tumor pathological stage T1-4N0-2M0. The primary endpoint was overall survival (OS). OS was calculated from the operation date to the date of death. The chi-square test was used for categorical variables, and a t test was used for continuous variables. Results: A total of 119 patients underwent L4 LND, and the procedure was more likely to be performed on upper lobe tumors (P=0.019). Patient distributions with respect to age, gender, smoking history, clinical stage, adjuvant therapy, tumor differentiation and tumor size were well balanced between two groups. More lymph nodes (LNs) were dissected in the L4D+ group than in the L4D- group (P<0.001). The rate of metastasis to L4 lymph nodes was 9.2%, which was comparable between patients with upper and lower lobe tumors (8.9% vs. 10.0%, P=1.000). The L4D+ group exhibited a significantly better OS than the L4D- group (median OS: undefined vs. 130 months, HR 0.47; 95% CI: 0.31-0.72; P=0.002). Multivariate analysis showed that L4 LND was an independent factor for OS. However, OS did not significantly differ between the two groups of cT1aN0 and cT1bN0 patients (OS: HR 0.44; 95% CI: 0.18-1.06; P=0.12). Conclusions: L4 LND is recommended for patients with left-sided NSCLC as an essential component of radical resection. The role of L4 LND in cT1a-bN0 disease warrants further study.

Zn-mediated decarboxylative carbagermatranation of aliphatic N-hydroxyphthalimide esters: evidence for an alkylzinc intermediate.

Alkyl nucleophiles synthesized by decarboxylation of the corresponding N-hydroxyphthalimide esters (NHP esters) would inherit the complex structure of natural carboxylic acids and result in useful cross-coupling fragments. Herein, we report the synthesis of alkyl carbagermatranes via Zn-mediated decarboxylation of NHP esters without Ni catalysis or photocatalysis. Mechanistic studies indicate that an alkyl zinc intermediate was involved; however, the generation of alkyl zinc will be inhibited in the presence of Ni. Hence, this study provides valuable resolution to the perplexing problem about whether organozinc was involved in recently emerging catalytic systems of NHP ester-Zn. Meanwhile, alkyl zinc reagents from NHP esters are compatible with aryl/alkyl bromides and iodides; therefore the scope of carbagermatranation in this work precedes that of in situ-generated organozinc from alkyl halides.

Alkylation-Terminated Catellani Reactions Using Alkyl Carbagermatranes.

The Catellani reaction has received substantial attention because it enables rapid multiple derivatization on aromatics. While using alkyl electrophiles to achieve ortho-alkylation was one of the earliest applications of the Catellani reaction, ipso-alkylation-terminated reactions with ß-H-containing reactants has not been realized to date. Herein, we report alkylation-terminated Catellani reaction using alkyl carbagermatranes (abbreviated as alkyl-Ge) as nucleophiles. The reactivity of alkyl-Ge and alkyl-B(OH)2 in this reaction is discussed. This approach enables efficient dialkylation with ß-H-containing reactants, which was previously inaccessible by Catellani reactions.

Entinostat reverses cisplatin resistance in esophageal squamous cell carcinoma via down-regulation of multidrug resistance gene 1.

Cisplatin resistance frequently occurs in esophageal squamous cell carcinoma (ESCC). The underlying mechanism for cisplatin resistance in ESCC remains largely obscure. Here we report that entinostat reversed cisplatin resistance in ESCC both in vitro and in vivo by induction of apoptosis and inhibition of cell proliferation, accompanied by a decrease of multidrug resistance gene 1 (MDR1), P-Src, Mcl-1, Cyclin D1 and an increase of cleaved PARP. MDR1 expression was associated with worsen survival of ESCC patients with cisplatin-based chemotherapy. Dasatinib potentiated entinostat to overcome cisplatin resistance. By inhibiting Src, dasatinib reduced the expression of MDR1 and Mcl-1. Furthermore, Obatoclax, an inhibitor of Mcl-1, obviously decreased the expression of MDR1, suggesting that entinostat might surmount cisplatin resistance in ESCC via a Src-Mcl-1-MDR1 pathway. Interestingly, cisplatin also enhanced the effect of entinostat both in vitro and in vivo. Our data disclose a molecular basis that entinostat reverses cisplatin resistance, and provide a promising strategy with combinatorial drugs to treat cisplatin resistant ESCC patients.

MMP1 promotes tumor growth and metastasis in esophageal squamous cell carcinoma.

Matrix metalloproteinases play an essential role in the progression of esophageal squamous cell carcinoma (ESCC). Here, we show that MMP1 expression was markedly increased in a majority of ESCC compared with nontumorous tissue. High expressions of MMP1 were closely associated with lymph node metastasis, microvessel density and advanced TNM stage. Kaplan-Meier and multivariate analyses indicated MMP1 as an independent factor for overall survival in two independent cohorts of 613 patients with ESCC. In vitro studies demonstrated that MMP1 overexpression resulted in enhanced cell viability, abilities of colony formation and cell migration. The knockdown of MMP1 in ESCC cells resulted in the opposite phenomenon. Consistently, in vivo data showed that ectopic expression of MMP1 promoted tumor growth and metastasis. Further study revealed that MMP1 facilitated ESCC through the activation of the PI3K/AKT pathway. Inhibition of the PI3K/AKT pathway by LY294002 significantly attenuated MMP1-mediated cell proliferation and migration. Taken together, our data suggest that MMP1 functions as an oncogene and serves as a prognostic biomarker and a potential therapeutic target in ESCC.

The epithelial-mesenchymal transition phenotype of metastatic lymph nodes impacts the prognosis of esophageal squamous cell carcinoma patients.

Epithelial-mesenchymal transition (EMT) plays a key role in tumor metastasis, but the significance of EMT phenotype to the prognosis of esophageal squamous cell carcinoma (ESCC) patients remains unclear. We used immunohistochemistry to examine the expression of the EMT-related proteins E-cadherin, N-cadherin and vimentin in samples of T3N1-3M0 ESCC from 155 primary tumors (PTs) with paired metastatic lymph nodes (MLNs) and 58 PTs without paired MLNs. Based on the expression pattern of the EMT markers, PTs and MLNs were classified as EMT wild, hybrid, null or complete type. The hybrid (42.7%) and complete (39.4%) types predominated among PTs, whereas the wild (34.2%) and hybrid (52.9%) types predominated among MLNs, and EMT phenotypes differed between the paired PTs and MLNs (P < 0.001). Univariate analysis revealed that, for PTs, the EMT phenotype was associated with N-stage (P = 0.039) but not patient survival, and that patients with complete or hybrid type MLNs had better overall survival (OS, P = 0.001) and disease-free survival (DFS, P = 0.005) than patients with null and wild type MLNs, especially those with N1-stage disease (P = 0.017 for OS, and P = 0.017 for DFS, respectively). Multivariate analysis revealed that wild and null type MLNs as well as older age and N2-3 stage were independent predictors of OS and DFS (P < 0.05). Thus MLNs exhibit EMT phenotypes that are distinct from those of their PT and may serve as a novel independent prognostic indicator in ESCC.

MIIP expression predicts outcomes of surgically resected esophageal squamous cell carcinomas.

The migration and invasion inhibitory protein (MIIP) was shown to function as a tumor suppressor gene in gliomas by inhibiting tumor cell growth, migration, and invasion. However, its role and clinical significance in esophageal squamous cell carcinoma (ESCC) have not been elucidated. We investigated the correlation of MIIP expression and clinical outcome in a group of surgically resected ESCCs. Tissue microarrays constructed of 253 surgically resected ESCC primary tumors and paired paracancerous normal esophageal epithelia were used for MIIP evaluation by immunohistochemistry. The clinical and prognostic significance of MIIP expression was analyzed statistically. The expression of MIIP expression in cancer tissues was increased significantly in comparison with the paired paracancerous normal epithelia (P < 0.001). And, MIIP expression was associated with ESCC cells' differentiation (P < 0.001). By Kaplan-Meier analysis, patients with low MIIP expression exhibited significantly improved overall survival (OS, P = 0.039) and a tendency of improved disease-free survival (DFS, P = 0.086) than those with high MIIP expression. In addition, MIIP expression could distinguish OS or DFS of patients with tumors in stage T3-4 (P = 0.020, 0.028), N0 (P = 0.008, 0.032), and stage II (P = 0.004, 0.019), as well as at lower thoracic esophagus (P = 0.024, 0.090). Multivariate analysis showed that MIIP expression was an independent prognostic factor in ESCC OS and DFS. In conclusion, MIIP expressed higher in ESCCs than in paracancerous normal esophageal epithelia and was a positive, independent prognostic factor in resected ESCCs.

The differential expression of OCT4 isoforms in cervical carcinoma.

OCT4 is a transcription factor involved in maintaining stem cell phenotype and pluripotential. However, it remains unclear the expression pattern and biological function of OCT4 isoforms in cervical cancer. Here, we reported that both nuclear OCT4A and cytoplasmic OCT4B were overexpressed in CC. OCT4A was responsible for self-renewal of cervical cancer stem-like cells (CCSCs). Furthermore, OCT4B overexpression in SiHa cervical cancer cell line significantly increased cell proliferation and tumorigenesis by inhibiting apoptosis. Moreover, OCT4B enhanced angiogenesis by the upregulation of CD34, VEGF, HIF-1α and IL-6, and promoted tumor cell mobility to the surrounding tissue by the upregulation of MMP2 and MMP9, and the induction of epithelial-mesenchymal transition (EMT). In conclusion, nuclear OCT4A may serve as a marker of CCSCs and the driving force for cervical cancer metastasis and recurrence, while cytoplasmic OCT4B may cooperate with OCT4A to regulate the progression of cervical cancer through inducing angiogenesis and EMT.