Three metal complexes [Cu(HL)Cl](C2H5OH)2] (complex 1), [Ni4L2(CH3COO)4(C2H5OH)4] (complex 2) and [CoHL2] (complex 3) based on 2,3-dihydroxybenzaldehyde-2-(2-aminophenyl)benzimidazole Schiff base (H2L) were synthesized by solvothermal reaction. The three complexes were characterized by FT-IR spectrometer, elemental analysis, thermogravimetric analysis, and X-ray single-crystal diffraction. X-ray single-crystal diffraction analysis confirmed that complex 1 belongs to monoclinic crystal system with P21/c space group, and complex 3 crystallizes in trigonal crystal system with R-3 space group. However, complex 2 crystallized in triclinic crystal system with P-1 space group and exhibits centrosymmetric tetranuclear crystallographic structure. Besides, MTT assay was studied antitumor activities against different tumor cells. The results show that the three complexes all have fine anticancer activities. Among them, complex 2 has significantly better anticancer properties against CNE-2Z cells than that of cisplatin. Finally, apoptosis and cell migration were studied to prove that complex 2 could inhibit tumor cells from proliferating in the manner of apoptosis and migration.

Three metal complexes [Ni-2 (HL)(2)(C2H5OH)(2)Cl-2]center dot 2C(2)H(5)OH (complex 1), [Co (HL) (L)] (complex 2) and [Zn-2(HL)(2) (CH3COO)(2)] (complex 3) derived from 5-bromosalicylaldehyde-2-(2-aminophenyl)benzimidazole Schiff base ligand (H2L) were synthesized and characterized by infrared (IR) spectroscopy, thermogravimetric (TG) analysis and powder X-ray diffraction (XRD). Single crystal X-ray diffraction analysis confirmed that complex 1 crystallized in binuclear octahedral structure with space group P2(1)/C and complex 2 displayed in mononuclear octahedral structure with space group P 121/c 1. While complex 3 produced binuclear pyramid structure with space group P 121/c 1. Herein, cobalt (II) salt was oxidized to form Schiff base cobalt (III) complex by coordinating three deprotonated groups. The MTT method was employed to determine the three complexes in vitro cytotoxicity effects against human lung cancer cells (A-549), liver cancer cells (SMMC-7721), breast cancer cells (MDA-MB-231) and nasopharyngeal carcinoma cells (CNE-2Z). The results showed that Co (III) complex has significant anticancer activity against human breast cancer MDA-MB-231 cells compared with cisplatin. The further study of its anticancer mechanisms exhibited that Co (III) complex could inhibit MDA-MB-231 cells proliferation through both apoptosis and DNA replication inhibition.

Seizure-related 6 homolog (mouse)-like 2 (SEZ6L2) was shown to be involved in transcription of a type 1 transmembrane protein for regulating cell fate. Until now, the expression and function of SEZ6L2 in various cancers, including colorectal cancer (CRC), were unclear. In the present study, we determined the expression of SEZ6L2 in a tissue microarray from patients with CRC and then, analysed the correlation between SEZ6L2 expression and the prognosis of the patients. Furthermore, the potential function of SEZ6L2 in CRC was determined using cell counting kit, colony formation assay and xenograft model in vitro and in vivo. Flow cytometry, Western blotting, immunohistochemical staining and a blocking experiment were employed to investigate the underlying mechanism of SEZ6L2 regulating CRC growth. Our results indicated that SEZ6L2 was significantly up-regulated in tumour tissues of patients with CRC compared with adjacent normal tissues. Up-regulation of SEZ6L2 was correlated with a poor prognosis in patients with CRC. In vitro experiments suggested that the knockdown of SEZ6L2 inhibits CRC cell growth and colony formation, but it has no significant impact on the invasion. The antitumour effects of shSEZ6L2 were also confirmed by a xenograft model. Investigations of the mechanisms indicated that the knockdown of SEZ6L2 impairs the growth of the CRC cells by inducing caspase-dependent apoptosis, which was mediated by mitochondria-related proteins. Furthermore, SEZ6L2 expression was inversely correlated with the expression of cytochrome C in malignant tissues in patients with CRC. Collectively, the present study indicates that SEZ6L2 is a potential prognosis biomarker and therapy target for CRC.