PEG-4000 formed polymeric nanoparticles loaded with cetuximab downregulate p21 & stathmin-1 gene expression in cancer cell lines.

Cetuximab (CTX) is known to have cytotoxic effects on several human cancer cells in vitro; however, as CTX is poorly water soluble, there is a need for improved formulations can reach cancer cells at high concentrations with low side effects. We developed (PEG-4000) polymeric nanoparticles (PEGNPs) loaded with CTX and evaluated their in vitro cytotoxicity and anticancer properties against human lung (A549) and breast (MCF-7) cancer cells. CTX-PEGNPs were formulated using the solvent evaporation technique, and their morphological properties were evaluated. Further, the effects of CTX-PEGNPs on cell viability using the MTT assay and perform gene expression analysis, DNA fragmentation measurements, and the comet assay. CTX-PEGNP showed uniformly dispersed NPs of nano-size range (253.7 ± 0.3 nm), and low polydispersity index (0.16) indicating the stability and uniformity of NPs. Further, the zeta potential of the preparations was -17.0 ± 1.8 mv. DSC and FTIR confirmed the entrapping of CTX in NPs. The results showed IC50 values of 2.26 µg/mL and 1.83 µg/mL for free CTX and CTX-PEGNPs on the A549 cancer cell line, respectively. Moreover, CTX-PEGNPs had a lower IC50 of 1.12 µg/mL in MCF-7 cells than that of free CTX (2.28 µg/mL). The expression levels of p21 and stathmin-1 were significantly decreased in both cell lines treated with CTX-PEGNPs compared to CTX alone. The CTX-PEGNP-treated cells also showed increased DNA fragmentation rates in both cancer cell lines compared with CTX alone. The results indicated that CTX-PEGNP was an improved formulation than CTX alone to induce apoptosis and DNA damage and inhibit cell proliferation through the downregulation of P21 and stathmin-1 expression.

A feasibility and safety study of concurrent chemotherapy based on genetic testing in patients with high-risk salivary gland tumors: Preliminary results.

BACKGROUND: This prospective study was conducted to evaluate the feasibility and safety of customized chemotherapy regimens based on the gene characteristics of salivary gland tumors. METHODS: Patients were enrolled with histologically confirmed intermediate or high grade, stage T3-4, N1-3 disease, and T1-2, N0 patients with a close (≤1 mm) or microscopically positive surgical margin were also enrolled in the study. All patients received radical surgery and postoperative concurrent chemoradiotherapy. To evaluate the responsiveness of therapies, the chemotherapy regimen was based on gene targets, ß-tubulin III, ABCB1, STMN1, and CYP1B1 (for docetaxel) and TYMS (for pemetrexed). The primary endpoints were treatment compliance and acute toxicities. RESULTS: A total of 20 patients were enrolled between September 2013 and January 2016. The median age was 46 years (range: 23-70 years). Genetic testing showed that 8 patients may have been sensitive to docetaxel, 5 patients may have been sensitive to pemetrexed, and 7 patients sensitive to either docetaxel or pemetrexed. All patients received the full dose of radiation. A total of 19 patients (95%) completed 2 cycles of concurrent chemotherapy (CCT). One patient treated concurrently with pemetrexed experienced grade 3 neutropenia. Three patients experienced grade 3 oral mucositis, and 2 patients experienced grade 3 dermatitis. CONCLUSION: Our study demonstrated that a CCT selecting method based on the gene targets associated with drug sensitivity was clinically feasible and safe. Further studies enrolled more patients with longer follow-up times are needed to confirm the clinical efficacy of this CCT selecting method.

miR-221 facilitates the TGFbeta1-induced epithelial-mesenchymal transition in human bladder cancer cells by targeting STMN1.

BACKGROUND: Distant metastasis is the major cause of cancer-related death, and epithelial-to-mesenchymal transition (EMT) has a critical role in this process. Accumulating evidence indicates that EMT can be regulated by microRNAs (miRNAs). miR-221, as oncogenes in several human cancers, was significantly up-regulated in bladder cancers. However, the role of miR-221 in the progression of bladder cancer metastasis remains largely unknown. METHODS: We used qRT-PCR and western blot to accurately measure the levels of miR-221, STMN1 and EMT markers in TGFß1 induced EMT of bladder cancer cells. miR-221 inhibitors were re-introduced into bladder cancer cells to investigate its role on tumor metastasis which was measured by MTT, wound healing, transwell invasion and adherent assays. Luciferase reporter assay was used to reveal the target gene of miR-221. RESULTS: miR-221 expression was greatly increased by TGFß1 in bladder cancer cell. miR-221 inhibition reversed TGFß1 induced EMT by sharply increasing the expression of the epithelial marker E-cadherin and decreasing the expression of the mesenchymal markers vimentin, Fibroactin and N-cadherin. Furthermore, miR-221 expression is positively correlated with malignant potential of bladder cancer cell through promoting loss of cell adhesion and prometastatic behavior. Luciferase reporter assay revealed that miR-221 negatively regulates STMN1 expression by direct targeting to the 3'UTR region of STMN1. CONCLUSIONS: Our study demonstrated that miR-221 facilitated TGFß1-induced EMT in human bladder cancer cells by targeting STMN1 and represented a promising therapeutic target in the process of metastasis.

Studying drug-tubulin interactions by X-ray crystallography.

Tubulin, the microtubule building-block, is the target of numerous small molecule compounds that interfere with microtubule dynamics. Several of these ligands are in clinical use as antitumor drugs. There have been numerous studies on these molecules, with two main objectives: to determine their mechanism of action and to find new compounds that would expand the arsenal available for cancer chemotherapy. Although these studies would undoubtedly benefit from structural data on tubulin, this protein has long resisted crystallization attempts. We have used stathmin-like domains (SLDs) of stathmin family proteins as a tool to crystallize tubulin and have obtained three-dimensional crystals of the tubulin:SLD complexes. As many tubulin ligands bind to these complexes, the crystals are valuable tools to study tubulin-drug interactions by X-ray crystallography. They open the way to a structure-based drug design approach.