Tspan protein family: focusing on the occurrence, progression, and treatment of cancer.

The Tetraspanins (Tspan) protein family, also known as the tetraspanin family, contains 33 family members that interact with other protein molecules such as integrins, adhesion molecules, and T cell receptors by forming dimers or heterodimers. The Tspan protein family regulates cell proliferation, cell cycle, invasion, migration, apoptosis, autophagy, tissue differentiation, and immune response. More and more studies have shown that Tspan proteins are involved in tumorigenesis, epithelial-mesenchymal transition, thrombosis, tumor stem cell, and exosome signaling. Some drugs and microRNAs can inhibit Tspan proteins, thus providing new strategies for tumor therapy. An in-depth understanding of the functions and regulatory mechanisms of the Tspan protein family, which can promote or inhibit tumor development, will provide new strategies for targeted interventions in the future.

C-Phycocyanin Ameliorates the Senescence of Mesenchymal Stem Cells through ZDHHC5-Mediated Autophagy via PI3K/AKT/mTOR Pathway.

The senescence of mesenchymal stem cells (MSCs) impairs their regenerative capacity to maintain tissue homeostasis. Numerous studies are focusing on the interventions and mechanisms to attenuate the senescence of MSCs. C-phycocyanin (C-PC) is reported to have multiple functions such as antitumor, antioxidation, anti-inflammation and anti-aging roles, but there is little research about the effects of C-PC on the senescence of MSCs. Here we investigated the roles and mechanism of C-PC on MSCs senescence. In vitro results showed that C-PC could reduce senescence, enhance proliferation, promote the adipogenic and osteogenic differentiation in senescent MSCs induced by oxidative stress. In vivo D-Galactose (D-Gal) induced rats aging models showed C-PC also increased the viability and differentiation of intrinsic senescent bone marrow derived MSCs (BMSCs). Furthermore, C-PC also decreased the levels of oxidative stress markers ROS or MDA, elevated the SOD activity, and increased the anti-inflammatory factors. Proteomic chip analysis showed that C-PC interacted with ZDHHC5, and their interaction was verified by pull down assay. Overexpression of ZDHHC5 aggravated the senescence of MSCs and greatly lessened the beneficial effects of C-PC on senescence. In addition, we found ZDHHC5 regulated autophagy by altering LC3, Beclin1 and PI3K/AKT/mTOR pathway. In summary, our data indicated that C-PC ameliorates the senescence of MSCs through zinc finger Asp-His-His-Cys (DHHC) domain-containing protein 5 (ZDHHC5) mediated autophagy via PI3K/AKT/mTOR pathway. The present study uncovered the key role of autophagy in MSCs senescence and PI3K/AKT/mTOR pathway may be a potential target for anti-senescence studies of MSCs.

Clinical exome sequencing identifies novel compound heterozygous mutations of the POMT2 gene in patients with limb-girdle muscular dystrophy.

OBJECTIVE: Mutations in protein O-mannosyltransferase 2 (POMT2) (MIM#607439) have been identified in severe congenital muscular dystrophy such as Walker-Warburg syndrome (WWS) and milder limb-girdle muscular dystrophy type 2N (LGMD2N). The aim of this study is to investigate the genetic causes in patients with LGMD2N. METHODS: Three patients diagnosed with mild limb-girdle muscular dystrophy were recruited. The genetically pathogenic variant was identified by clinical exome sequencing, and healthy controls were verified by Sanger sequencing. RESULTS: Novel compound heterozygous mutations c.800A > G and c.1074_1075delinsAT of POMT2 were revealed in one affected individual by clinical exome sequencing. There was no report of these two variants and predicted to be highly damaging to the function of the POMT2. CONCLUSION: The novel variants extend the spectrum of POMT2 mutations, which promotes the prognostic value of testing for POMT2 mutations in patients with LGMD2N.

Clinical Exome Sequencing Identifies NDP Gene Variants in Two Chinese Families with X-Linked Norrie Disease.

Purpose: To explore the genetic defects in two Chinese families with X-linked Norrie disease (ND). Methods: We analyzed two Chinese families with ND at molecular level through clinical exome sequencing and the variations were identified by Sanger sequencing. Results: Two genetic variations were found in the NDP gene by clinical exome sequencing, a partial deletion of 801 bp contained the whole exon 2 and a missense variant (164G>A) within codon 55 that resulted in the interchange of cysteine by phenylalanine. Clinical findings were more severe in the patients who presented the missense variant. Conclusion: We report two genetic variations in the NDP gene in Chinese that extend the mutational and phenotypic spectra of NDP gene, and also demonstrate the feasibility of clinical exome sequencing in application of molecular diagnosis.

Targeted Antitumor Mechanism of C-PC/CMC-CD55sp Nanospheres in HeLa Cervical Cancer Cells.

In vitro studies had shown that C-Phycocyanin (C-PC) inhibited cervical cancer HeLa cells growth. We constructed C-PC/CMC-CD55sp nanospheres using C-PC, Carboxymethyl Chitosan (CMC), and CD55 ligand peptide (CD55sp) to allow for targeted antitumor effects against HeLa cells in vitro and in vivo. The characteristics of the nanospheres were determined using FTIR, electron microscopy, and laser particle size analysis. Flow cytometry, laser confocal microscopy and small animal imaging system showed the targeting of C-PC/CMC-CD55sp nanospheres on HeLa cells. Subsequently, the proliferation and apoptosis were analyzed by Cell Counting Kit-8 (CCK-8), flow cytometry, TUNEL assay and electron microscopy. The expression of the apoptosis-related protein was determined using western blot. The stainings of Hematoxylin and Eosin (HE) were employed to evaluate the cell condition of tumor tissue sections. The cytokines in the blood in tumor-bearing nude mice was determined using ELISA. These results showed that C-PC/CMC-CD55sp nanospheres were successfully constructed and targeted HeLa cells. The constructed nanospheres were more effective than C-PC alone in inhibiting the proliferation and inducing apoptosis in HeLa cells. We also found that C-PC/CMC-CD55sp nanospheres had a significant inhibitory effect on the expression of antiapoptotic protein Bcl-2 and a promotion on the transformation of caspase 3 to cleaved caspase 3. C-PC/CMC-CD55sp nanospheres played an important role in tumor suppression, reduced the expression TGF-ß, and increased IL-6 and TNF-α. This study demonstrates that the constructed new C-PC/CMC-CD55sp nanospheres exerted targeted antitumor effects in vivo and in vitro which provided a novel idea for application of C-PC, and provided experimental basis for comprehensive targeted treatment of tumors.

Molecular Mechanism of Anti-Cancer Activity of the Nano-Drug C-PC/CMC-CD59sp NPs in Cervical Cancer.

The novel tumor targeted nano-drug C-PC/CMC-CD59sp nanoparticles were constructed with carbocymethyl chitosan (CMC), C-phycocyanin (C-PC) and CD59 specific ligand peptide (CD59sp). The anti-tumor drug mechanism of the C-PC/CMC-CD59sp NPs was further explored in cervical cancer cells (HeLa and SiHa) in vitro and in vivo. We found that the C-PC/CMC-CD59sp NPs could inhibit the proliferation and induce G0/G1 cell cycle arrest in cervical cancer HeLa and SiHa cells, and the cell proliferation was reduced in a dose-dependent manner. We further found that the C-PC/CMC-CD59sp NPs regulated the cell cycle via up-regulating the expression of p21, and then down-regulating the expressions of Cyclin D1 and CDK4 in vivo. Compared with C-PC and C-PC/CMC NPs, the pro-apoptosis effects of the C-PC/CMC-CD59sp NPs were more significant for HeLa and SiHa cells in vitro. Moreover, the C-PC/CMC-CD59sp NPs up-regulated the expression of cleaved caspase-3 and down-regulated the expression of bcl-2. In addition, compared with C-PC and C-PC/CMC, the C-PC/CMC-CD59sp NPs significantly inhibited MMP-2 protein expression in vivo. Our data suggested that the anti-tumor effects of C-PC/CMC-CD59sp NPs were better than C-PC and C-PC/CMC NPs. Our laboratory constructed a new drug delivery system and proved the effective antitumor effects of C-PC/CMC-CD59sp, which would widen the application of C-PC as a potential anti cervical cancer drug.

A study on screening and antitumor effect of CD55-specific ligand peptide in cervical cancer cells.

BACKGROUND: To improve the targeting ability of antitumor drugs, we identified the antigens with high expression on the surface of tumor cells associated with tumor escape, such as the complement regulatory protein CD55 molecule, which is also known as the decay accelerating factor. In this study, phage display technology was used to screen and identify CD55-specific ligand peptide (CD55sp) bound to CD55 molecule on the surface of cervical cancer HeLa cells. We then explored the role of this peptide in inhibiting the growth of cervical cancer cells in vitro. Our characterization of CD55sp will provide implication for tumor target therapy. METHODS: The phage bound to the surface of HeLa cells were isolated by phage display technology. Positive phage clones were identified by ELISA. Phage was then amplified and determined by agarose gel electrophoresis after monoclonal DNA extraction. DNA sequencing and bioinformatical analysis were conducted to obtain specific ligand peptides. Flow cytometry and immunofluorescence were used to measure the expression of CD55 molecule on the surface of tumor and normal cells. Subsequently, the effects of CD55sp on the proliferation and apoptosis of HeLa and SiHa cells were determined by Cell Counting Kit-8 (CCK-8), flow cytometry, and TUNEL assay, respectively. The morphology of apoptotic cells was examined by electron microscope. The distribution of Cleaved caspase-3 was detected by immunofluorescence. The expression of bcl-2 and Cleaved caspase-3 were determined by Western blot. RESULTS: The results showed that the peptide (QVNGLGERSQQM) can bind to the CD55 molecule on the surface of cervical cancer HeLa and SiHa cells as a ligand peptide. It can also effectively inhibit the proliferation of cervical cancer cells and induce cell apoptosis. CONCLUSION: This study demonstrates that CD55sp screened by phage display technology plays a strong antitumor role.

C-Phycocyanin exerts anti-cancer effects via the MAPK signaling pathway in MDA-MB-231 cells.

BACKGROUND: Triple-negative breast cancer is a biological subtype of breast cancer, which is unresponsive to conventional chemotherapies and has a poor prognosis. C-Phycocyanin (C-PC), a marine natural purified from Spirulina platensis, has been investigated that has anti-cancer function. The mitogen activated protein kinase (MAPK) pathway plays a crucial role in the development and progression of cancer. Therefore, we would like to study the anti-cancer effects of C-phycocyanin in the treatment of triple-negative breast cancer, and explore the role of MAPK pathway in the anti-tumor effects of C-phycocyanin. METHODS: Cell proliferation, cell cycle, cell apoptosis and cell migration were explored in breast cancer MDA-MB-231 cell lines. AKT, MAPK and membrane death receptor signaling were evaluated in MDA-MB-231 cell lines. RESULTS: Our study indicated that C-phycocyanin inhibited cell proliferation and reduced colony formation ability of MDA-MB-231 cells. Furthermore, C-phycocyanin induced cell cycle G0/G1 arrest by decreasing protein expression levels of Cyclin D1 and CDK-2 and increasing protein expression levels of p21 and p27. In addition, C-phycocyanin induced cell apoptotic by activating cell membrane surface death receptor pathway. Besides, C-phycocyanin down-regulated the protein expression levels of cyclooxygenase-2, and further inhibited MDA-MB-231 cells migration. We also found cell death induced by C-phycocyanin was carried through the MAPK signaling pathways. C-Phycocyanin was able to induce MDA-MB-231 cell apoptosis by activating p38 MAPK and JNK signaling pathways while inhibiting ERK pathway. CONCLUSIONS: C-Phycocyanin exerted anti-cancer activity via the MAPK signaling pathway in MDA-MB-231 cells.

Targeted antitumor effects of C-PC/CMC-CD55sp nanospheres on cervical carcinoma Caski cells / 中国肿瘤生物治疗杂志

@# Objective: To prepare a new type of phycocyanin/carboxymethyl chitosan-CD55 ligand peptide (CPC/CMC-CD55sp) nanospheres, and to study its targeted therapeutic effect on cervical cancer Caski cells. Methods: The novel CPC/CMC-CD55sp nanospheres (CPC/CMC-CD55sp) were synthesized by ionic cross-linking method, and the properties of nanospheres were observed by transmission electron microscopy (DLS) and fourier transform infrared spectroscopy (FTIR). The expression of CD55 on the surface of Caski and fibroblast (L-929) cells was detected by Western blotting and flow cytometry. The effect of nanospheres on the proliferation of Caski cells was detected by CCK-8. Flow cytometry and fluorescence microscopy were used to detect the uptake of microspheres by Caski cells; Western blotting and flow cytometry were used to detect the effect of CPC/CMC-CD55sp on expressions of apoptosis-related proteins and apoptosis rate in Caski cells; the hemolysis test was used to determine the biological safety of the drug. Results: CPC/ CMC-CD55sp was successfully prepared with good morphology and uniform diameter; and CD55 was highly expressed on the surface of Caski cells but low expressed on the surface of L-929 cells (P<0.01). CPC/CMC-CD55sp could targeted and efficiently reach Caski cells and be ingested into the cells. It exhibited weak hemolysis effect on human peripheral blood, which was in the safe range. CPC/ CMC-CD55sp displayed obvious inhibitory effect on Caski cell proliferation, and could induce cell apoptosis (P<0.05 or P<0.01). Conclusion: The new CPC/CMC-CD55sp can targeted inhibit the growth of cervical cancer Caski cells via inducing its apoptosis and has good bio-safety, which provides a new idea for the research and development of anti-tumor marine drugs.

Phycocyanin: A Potential Drug for Cancer Treatment.

Phycocyanin isolated from marine organisms has the characteristics of high efficiency and low toxicity, and it can be used as a functional food. It has been reported that phycocyanin has anti-oxidative function, anti-inflammatory activity, anti-cancer function, immune enhancement function, liver and kidney protection pharmacological effects. Thus, phycocyanin has an important development and utilization as a potential drug, and phycocyanin has become a new hot spot in the field of drug research. So far, there are more and more studies have shown that phycocyanin has the anti-cancer effect, which can block the proliferation of cancer cells and kill cancer cells. Phycocyanin exerts anti-cancer activity by blocking tumor cell cell cycle, inducing tumor cell apoptosis and autophagy, thereby phycocyanin can serve as a promising anti-cancer agent. This review discusses the therapeutic use of phycocyanin and focuses on the latest advances of phycocyanin as a promising anti-cancer drug.

The Targeted Antitumor Effects of C- PC/CMC-CD59sp Nanoparticles on HeLa Cells in Vitro and in Vivo.

The novel C-PC/CMC-CD59sp-NPs were made by carbocymethyl chitosan (CMC) loading C-phycocyanin (C-PC) with the lead of CD59 specific ligand peptide (CD59sp) for targeting, and the characteristics and targeted anti-tumor mechanism were explored in order to realize the targeted therapy of C-PC on the growth of HeLa cells both in vitro and vivo. The targeting nanoparticles were synthesized by ionic-gelation method, and the optimal condition was selected out by orthogonal analysis. The properties of nanoparticles were observed by laser particle analyzer and dynamic light scattering (DLS) and Fourier Transform Infrared Spectrometer (FTIR). The effects of nanoparticles on the proliferation of HeLa cells in vitro were assessed by MTT assay. The mice model with tumor was constructed by subcutaneous injection of HeLa cells into the left axilla of NU/NU mice. The weight of tumor and the spleen were tested. The expression quantities of cleaved caspase-3, Bcl-2 were determined by western blot and immunofluorescent staining. Results showed the morphology of the finally prepared nanoparticles was well distributed with a diameter distribution of 200±11.3 nm and zeta potential of -19.5±4.12mV. Under the guidance of CD59sp, the targeting nanoparticles could targetedly and efficiently arrive at the surface of HeLa cells, and had obvious inhibitory effect on HeLa cells proliferation both in vitro and vivo. Moreover, the nanoparticles could induce cell apoptosis by up-regulation of cleaved caspase-3 proteins expression, but down-regulation of Bcl-2 and cyclinD1 proteins. Our study provided a new idea for the research and development of marine drugs, and supplied a theoretical support for the target therapy of anticancer drug.

CRL4B interacts with and coordinates the SIN3A-HDAC complex to repress CDKN1A and drive cell cycle progression.

CUL4B, a scaffold protein that assembles the CRL4B ubiquitin ligase complex, participates in the regulation of a broad spectrum of biological processes. Here, we demonstrate a crucial role of CUL4B in driving cell cycle progression. We show that loss of CUL4B results in a significant reduction in cell proliferation and causes G1 cell cycle arrest, accompanied by the upregulation of the cyclin-dependent kinase (CDK) inhibitors (CKIs) p21 and p57 (encoded by CDKN1A and CDKN1C, respectively). Strikingly, CUL4B was found to negatively regulate the function of p21 through transcriptional repression, but not through proteolysis. Furthermore, we demonstrate that CRL4B and SIN3A-HDAC complexes interact with each other and co-occupy the CDKN1A and CDKN1C promoters. Lack of CUL4B led to a decreased retention of SIN3A-HDAC components and increased levels of acetylated H3 and H4. Interestingly, the ubiquitylation function of CRL4B is not required for the stable retention of SIN3A-HDAC on the promoters of target genes. Thus, in addition to directly contributing to epigenetic silencing by catalyzing H2AK119 monoubiquitylation, CRL4B also facilitates the deacetylation function of SIN3A-HDAC. Our findings reveal a coordinated action between CRL4B and SIN3A-HDAC complexes in transcriptional repression.