This study was carried out to express human epidermal growth factor (hEGF) in Pichia pastoris GS115. For this aim, the hEGF gene was cloned into the pPIC9K expression vector, and then integrated into P. pastoris by electroporation. ELISA-based assay showed that the amount of hEGF secreted into the medium can be affected by the fermentation conditions especially by culture medium, pH and temperature. The best medium for the optimal hEGF production was BMMY buffered at a pH range of 6.0 and 7.0. The highest amount of hEGF with an average yield of 2.27μg/mL was obtained through an induction of the culture with 0.5% (v/v) methanol for 60h. The artificial neural network (ANN) analysis revealed that changes in both pH and temperature significantly affected the hEGF production with the pH change had slightly higher impact on hEGF production than variations in the temperature.
Growth factors are polypeptides that are critical for the initiation, progression, and metastasis of cancer. Most tumor cells are capable of synthesizing particular growth factors leading to constitutive pathway activation in these cells through autocrine signaling. Epidermal growth factor (EGF) is a potent mitogenic peptide that exerts direct effects on the proliferation and differentiation of tumor cells in carcinogenesis. By contrast, vascular endothelial growth factor (VEGF) is vital for the invasion and metastasis of neoplasms through the formation of new blood vessels from mature endothelial cells. In this study, we investigated the association between functional polymorphisms of both the EGF and VEGF genes and colorectal cancer (CRC) susceptibility. A total of 130 CRC patients and 212 healthy controls were recruited for this case-control study. Genotyping of genetic variants was conducted via real-time polymerase chain reaction (PCR) amplification with allele-specific TaqMan probes. None of the genotypes of the EGF +61 A>G and VEGF +936 C>T variants was significantly associated with CRC susceptibility among the Malaysian subjects evaluated (P > 0.05). The observed frequency distributions of the EGF +61 A>G polymorphism genotypes showed ethnic heterogeneity, which was not the case for the VEGF +936 C>T genotypes. In conclusion, no positive correlation between these functional polymorphisms and CRC risk was found in this Malaysian population. Studies of the EGF and VEGF genes and CRC susceptibility are scarce, and the results reported thus far differ from one population to another. Hence, more replication studies are warranted before any firm conclusions can be made.
Despite available data from other Asian countries, the prevalence of epidermal growth factor receptor (EGFR) mutations among lung adenocarcinoma patients has not been reported in Malaysia. This study sought to determine the frequency of EGFR mutations among multiethnic Malaysian patients diagnosed with lung adenocarcinoma.
To evaluate the response and progression-free survival (PFS) of Malaysian patients with advanced lung adenocarcinoma and unknown epidermal growth factor receptor (EGFR) mutation status treated with gefitinib.
Studies of genetic mutations that have been used in predicting glioma prognosis have revealed a complex relationship between clinical and genetic factors. Epidermal growth factor (EGF) and the NAT2 gene play a central role in carcinogenesis. An adenine (A) to guanine (G) single nucleotide polymorphism at position 61 in the 5'-untranslated region (5'-UTR) of the EGF gene has been found to be associated with levels of EGF production, and the mutations in the NAT2 gene have been postulated as a risk factor for cancer. We investigated EGF and the NAT2 gene in 13 glioma tissue samples and 12 normal controls. In the EGF 5'-UTR 61G polymorphism, the heterozygote GA was the most common genotype in the glioma patients. In the NAT2 polymorphism at nucleotide position 857G/A, the G allele and the GG genotype were the most prevalent forms in both the glioma and normal samples. We did not find any homozygous AA genotypes in the glioma patients. Based on this preliminary evidence, the EGF 5'-UTR at position 61 and the NAT2 SNP at position 857 polymorphisms are associated with increased risk for glioma.
Recombinant human epidermal growth factor (EGF) was successfully expressed as a fusion protein in Escherichia coli system. This system was used OmpA signal sequence to produce soluble protein into the periplasm of E. coli. Human EGF (hEGF) synthesized in bacterial cell was found to be similar in size with the original protein and molecular weight approximately at 6.8 kDa. Cell proliferation assay was conducted to characterize the biological activity of hEGF on human dermal fibroblasts. The synthesized hEGF was found to be functional as compared with authentic hEGF in stimulating cell proliferation and promoting growth of cell. In comparison of biological activity between synthesized and commercial hEGF on cell proliferation, the results showed there was no significant different. This finding indicates the synthesized hEGF in E. coli system is fully bioactive in vitro.
The efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in EGFR mutation-positive non-small-cell lung cancer (NSCLC) patients necessitates accurate, timely testing. Although EGFR mutation testing has been adopted by many laboratories in Asia, data are lacking on the proportion of NSCLC patients tested in each country, and the most commonly used testing methods.
We report a woman presenting with respiratory failure due to a right-sided pleural effusion, lung metastases and lymphangitis carcinomatosis from advanced lung adenocarcinoma in the third trimester of pregnancy, who showed good response to EGFR tyrosine kinase inhibitor.
Considering the great potential of natural products as anticancer agents, the present study was designed to explore the molecular mechanisms responsible for anticancer activities of Mesua ferrea stem bark extract against human colorectal carcinoma. Based on MTT assay results, bioactive sub-fraction (SF-3) was selected for further studies using HCT 116 cells. Repeated column chromatography resulted in isolation of less active α-amyrin from SF-3, which was identified and characterized by GC-MS and HPLC methods. α-amyrin and betulinic acid contents of SF-3 were measured by HPLC methods. Fluorescent assays revealed characteristic apoptotic features, including cell shrinkage, nuclear condensation, and marked decrease in mitochondrial membrane potential in SF-3 treated cells. In addition, increased levels of caspases-9 and -3/7 levels were also observed in SF-3 treated cells. SF-3 showed promising antimetastatic properties in multiple in vitro assays. Multi-pathway analysis revealed significant down-regulation of WNT, HIF-1α, and EGFR with simultaneous up-regulation of p53, Myc/Max, and TGF-β signalling pathways in SF-3 treated cells. In addition, promising growth inhibitory effects were observed in SF-3 treated HCT 116 tumour spheroids, which give a hint about in vivo antitumor efficacy of SF-3 phytoconstituents. In conclusion, these results demonstrated that anticancer effects of SF-3 towards colon cancer are through modulation of multiple molecular pathways.