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Objective: To investigate the mechanism by which fragile X mental retardation protein (FMRP) regulates ferroptosis evasion in colorectal cancer (CRC) cells., Methods: We examined FMRP expression levels in CRC cell lines using RT-qPCR and Western blotting and analyzed the biological functions and signaling pathways involved in FMRP-mediated regulation of CRC progression using the TCGA database. A lentiviral FMRP overexpression vector (Lv-FMRP) and 3 knockdown vectors (siFMRP-1, siFMRP-2, and siFMRP-3) were constructed, and their effects on proliferation of HCT116 cells were examined using CCK8 assay and plate clone formation assay; the changes in cell ferroptosis level was determined using MDA/ROS/GSH/Fe 2+ kits, mitochondrial membrane potential changes were detected using JC-1 fluorescence staining, and the expressions of proteins associated with ferroptosis and the RAS/MAPK signaling pathway were detected using Western blotting. The subcutaneous tumorigenic potential of the transfected cells was evaluated in nude mice., Results: Compared with normal colonic mucosal epithelial NCM460 cells, the CRC cell lines had significantly higher FMRP expression level. Bioinformatics analysis suggested the involvement of FMRP in regulation of reactive oxygen, oxidative stress-induced cell death, mitochondrial respiration, and glutathione metabolism pathways. In the cell experiments, FMRP knockdown significantly inhibited proliferation of HCT116 cells, lowered cellular GSH content, increased MDA and ROS levels, Fe 2+ fluorescence intensity, and mitochondrial membrane potential, and decreased SLC7A11/GPX4 protein expressions and the phosphorylation levels of ERK, MEK, MAPK, and RAS proteins; FMRP overexpression resulted in the opposite changes in the cells. In the tumor-bearing nude mice, HCT116 cells with FMRP knockdown showed attenuated tumorigenic potential with lowered xenograft growth rate and reduced SLC7A11 expression in the xenograft., Conclusion: The high expression of FMRP inhibits ferroptosis in CRC cells and promotes progression of CRC by activating the RAS/MAPK signaling pathway.

Objective: To investigate the role and the mechanism of Ras-associated binding protein23 (RAB23) in the migration and invasion of esophageal squamous cell carcinoma (ESCC) cells. Methods: RAB23 mRNA levels were measured in 16 pairs of ESCC and adjacent normal tissues via real-time polymerase chain reactions. RAB23 mRNA levels in the ESCC and adjacent normal tissues of dataset GSE20347 deposited in the Gene Expression Omnibus (GEO) database were also analyzed. Immunohistochemistry (IHC) was used to detect the RAB23 protein expressions in 106 pairs of ESCC and adjacent normal tissues, as well as in the lymph glands and primary tumor tissues of 33 patients with positive lymph nodes and 10 patients with negative lymph nodes. Endogenous RAB23 expression was transiently depleted using siRNAs (si-NC, si-RAB23-1, and si-RAB23-9) or stably reduced using shRNAs (sh-NC and sh-RAB23) in ESCC KYSE30 and KYSE150 cells, and the knockdown efficiency was tested using Western blot assays. Cell counting kit-8 assays and mouse xenograft models were used to test the proliferation of ESCC cells . Transwell assays and tail vein-pulmonary metastasis models in immunocompromised mice were used to examine the migration and invasion of ESCC cells. Cell adhesion assays were used to test the adhesion of ESCC cells. RNA-seq assays were used to analyze how RAB23 knockdown influenced the expression profile of ESCC cells and the implicated signal pathways were confirmed using Western blot assays. Results: The RAB23 mRNA expression in 16 cases of ESCC tissues was 0.009 7±0.008 9, which was markedly higher than that in adjacent normal tissues (0.003 2±0.003 7, P =0.006). GEO analysis on RAB23 expressions in ESCC and adjacent normal tissues showed that the RAB23 mRNA level in ESCC tissues (4.30±0.25) was remarkably increased compared with their normal counterparts (4.10±0.17, P= 0.037). Among the 106 pairs of ESCC and tumor-adjacent normal tissues, 51 cases exhibited low expression of RAB23 and 55 cases showed high expression of RAB23, whereas in the paired tumor-adjacent normal tissues 82 cases were stained weakly and 24 strongly for RAB23 protein. These results indicated that RAB23 expression was markedly increased in ESCC tissues ( P <0.001). Additionally, only 1 out of 33 primary ESCC tissues with positive lymph nodes showed low RAB23 protein expression. On the other hand, 7 samples of primary ESCC tissues with negative lymph nodes were stained strongly for RAB23 while its level in the other 3 samples was weak. These results showed that RAB23 expression was remarkably increased in primary ESCC tissues with positive lymph nodes compared with those with negative lymph nodes ( P =0.024). Further tests showed that 32 out of 33 positive lymph nodes were stained strongly for RAB23, whereas no negative lymph nodes ( n =10) exhibited high expression of RAB23 ( P <0.001). Both transient and stable knockdown of endogenous RAB23 expression failed to cause detectable changes in the proliferation of KYSE30 cells in vitro and in vivo , but attenuated the migration and invasion of KYSE30 cells as well as the invasion of KYSE150 cells. RAB23 knockdown was found to significantly decrease the number of adhesive KYSE30 cells in the sh-RAB23 group (313.75±89.34) compared with control cells in the sh-NC group (1 030.75±134.29, P <0.001). RAB23 knockdown was also found to significantly decrease the number of adhesive KYSE150 cells in the sh-RAB23 group (710.5±31.74) compared with the number of control cells in the sh-NC group (1 005.75±61.09, P <0.001). RNA-seq assays demonstrated that RAB23 knockdown using two siRNAs targeting RAB23 mRNA markedly impaired focal adhesion-related signal pathways, and decreased the levels of phosphorylated FAK (p-FAK) and phosphorylated paxillin (p-paxillin) in KYSE30 and KYSE150 cells. Conclusions: Significantly increased RAB23 in ESCC tissues positively correlates with lymph node metastasis. Depleted RAB23 expression attenuates focal adhesion-related signal pathways, thus impairing the invasion, metastasis, and adhesion of ESCC cells.

Objective: To study the effects of subchronic aluminum exposure on LTP and activities of RAS and ERK in rats in vivo. Methods: 24 Wistar rats were randomly divided into control group、low-dose group、medium-dose group and high-dose group, and received saline (control group) or Al (mal) (3) (15 μmol、kg、30 μmol、kg or 45 μmol/kg) via intraperitoneal injection (i.p.) for 8 weeks, respectively. The fEPSP in CA1 region were recorded by field potentiation technique in vivo and the hippocampal activities of RAS and ERK were examined by ELISA. Results: The fEPSP amplitudes of the control group were 1.90±0.19, 1.64±0.15 and 1.54±0.08 at 1, 30 and 60 min after HFS, respectively. The fEPSP amplitudes of the low-dose group were 1.40±0.06 at 60 min, which represented a statistically significant decrease compared to the control group ( P <0.05) ; these values at 30min and 60min dropped to 1.33±0.20 and 1.12±0.07 in the medium-dose group ( P <0.05) and further decreased to 1.05±0.05 and 0.91±0.10 in the high-dose group ( P <0.05) . And the activity dose-dependent decreases were observed both in RAS and ERK: compared with the control group and the low-dose group, the activities of RAS and ERK of the medium-dose and high-dose group significantly decreased ( P <0.05) and compared with the medium-dose group, the activities of the high-dose group statistically dropped ( P <0.05) . Conclusion: RAS and ERK may be related to the suppression of LTP by subchronic aluminum exposure and the RAS-MAPK transduction pathway may be involved in the damage of learning and memory induced by aluminum.

Objective: To explore the effect of microRNA miR-143 on the proliferation of cervical cancer HeLa cells through targeted regulating the expression of K-ras gene. Methods: The luciferase report carrier containing wild type 3'-UTR of K-ras gene (K-ras-wt) or mutated 3'-UTR of the K-ras (K-ras-mut) were co-transfected with iR-143 mimic into the HeLa cells respectively, and the targeting effect of miR-143 in the transfectants was verified by the dual luciferase report system. HeLa cells were also transfected with miR-143 mimic (miR-143 mimic group), mimic control (negative control group), and miR-143 mimic plus K-ras gene (miR-143 mimic+ K-ras group), respectively. The expression of miR-143 in the transfected HeLa cells was detected by real-time PCR (RT-PCR), and the expression of K-ras protein was detected by Western blot. The cell proliferation activity of each group was examined by MTT assay. In addition, human cervical cancer tissue samples ( n =5) and cervical intraepithelial neoplasia tissue samples ( n =5) were also examined for the expression of miR-143 and K-ras protein by RT-PCR and Western blot, respectively. Results: The luciferase report assay showed that co-transfection with miR-143 mimic decreased the luciferase activity of the K-ras-wt significantly, but did not inhibit the luciferase activity of the K-ras-mut. The expression of miR-143 in the HeLa cells transfected with miR-143 mimic was significantly higher than that in the HeLa cells transfected with the mimic control (3.31±0.45 vs 0.97±0.22, P <0.05). The MTT assay revealed that the cell proliferative activity of the miR-143 mimic group was significantly lower than that of the negative control group ( P <0.05), and the cell proliferative activity of the miR-143 mimic+ K-ras group was also significantly lower than the control group ( P <0.05) but higher than the miR-143 mimic group significantly ( P <0.05). The expression levels of K-ras protein in the miR-143 mimic group, the negative control group and the miR-143 mimic+ K-ras group were lowest, moderate, and highest, respectively (115.27±34.08, 521.36±41.89, and 706.52±89.44, all P <0.05). In the tissue samples, the miR-143 expression in the cervical cancer group was significantly lower than that of the cervical intraepithelial neoplasia group (0.32±0.06 vs. 0.93±0.17, P <0.05); whereas the K-ras protein expression in the cervical cancer group was significantly higher than that in the cervical intraepithelial neoplasia group (584.39±72.34 vs. 114.23±25.82, P <0.05). Conclusions: In vitro, miR-143 can inhibit the proliferative activity of HeLa cells through targeted regulating the expression of K-ras gene. In human cervical cancer tissues of a small sample set, the expression of miR-143 is downregulated, and the expression of K-ras is upregulated.

Background: Epidermal growth factor receptor (EGFR) and KRAS must be detected mutation status before patients of lung cancer use targeted drugs. The aim of this study is to elucidate the significance of EGFR and KRAS mutation in fine needle aspiration (FNA) cytology suspension specimens of non-small cell lung carcinoma., Methods: EGFR gene exons 18-21 and KRAS codons 12, 13 of exons 2 were performed by Real-time PCR methods in fine needle aspiration cytology suspension specimens of lymph nodes., Results: 85 metastasis lymph nodes were detected in fine needle aspiration cytology samples of lung cancer. EGFR mutation rate was 37.3%. KRAS mutation rate was 7.2%. 19 formalin fixed paraffin-embedded tissue specimens were available and match cytology specimens. Analysis of EGFR mutation status in those samples revealed agreement with the results obtained in cytological samples (kappa=1.0). Clinical follow-up was available for 13 who presented with stage IV disease. Based on the identification of such mutations, these patients received subsequent therapy with a TKI in clinic. We observed two cases complete remission (16.7%) and 8 cases partial remission (66.7%) and three had ongoing stable disease., Conclusions: Fine-needle aspiration cytology samples were detected EGFR and KRAS mutation. The method which collects samples was easier, simple and convenient. This method has higher application value in clinical treatment.
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Objective: To evaluate the effect of combined targeting of MEK and PI3K signaling pathways on K-ras mutated non-small cell lung cancer cell line A549 cells and the relevant mechanisms., Methods: A549 cells were treated with different concentrations of two inhibitors. Growth inhibition was determined by MTT assay. According to the results of MTT test, the cells were divided into four groups: the control group, PI3K inhibitor group (GDC-0941,0.5 and 5.0 µmol/L), combination group I (0.5 µmol/L AZD6244+0.5 µmol/L GDC-0941) and combination group II (5.0 µmol/L AZD6244+5.0 µmol/L GDC-0941). The cell cycle and apoptosis were analyzed by flow cytometry. The expression of proteins related to apoptosis was tested with Western blot., Results: Both GDC-0941 and AZD6244 inhibited the cell proliferation. The combination group II led to a stronger growth inhibition. The combination group I showed an antagonistic effect and combination group II showed an additive or synergistic effect. Compared with the control group, the combination group I led to reduced apoptotic rate [(20.70 ± 0.99)% vs. (18.65 ± 0.92 )%, P > 0.05]; Combination group II exhibited enhanced apoptotic rate [(37.85 ± 3.18)% vs. (52.27 ± 4.36)%, P < 0.01]. In addition, in the combination group II, more A549 cells were arrested in G0/G1 phase and decreased S phase (P < 0.01), due to the reduced expressions of CyclinD1 and Cyclin B1, the increased cleaved PARP and the diminished ratio of Bcl-2/Bax., Conclusions: For single K-ras mutated NSCLC cell line A549 cells, combination of RAS/MEK/ERK and PI3K/AKT/mTOR inhibition showed synergistic effects depending on the drug doses. Double pathways targeted therapy may be beneficial for these patients.

Background and Objective: It has been proven that biomarkers play a key role in the individualized treatment of lung cancer. Correlations between expressions of TUBB3/STMN1 and gene mutations of epidermal growth factor receptor (EGFR), Kirsten rat sarcoma viral oncogene homolog (KRAS), v-raf murine sarcoma viral oncogene homolog B (BRAF), phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) in non-small cell lung cancer (NSCLC) would be investigated and this may provide essential significance on prognosis and predictions of drug efficiency., Methods: This study total enrolled 46 NSCLC patients. Tumor specimens were resected. The gene expressions of TUBB3, STMN1 were analyzed using branched DNA-liquidchip, and EGFR, KRAS, BRAF, PI3K gene mutations were detected by xTAG-liquidchip. Correlations between gene expressions and gene mutations were further analyzed by Spearman., Results: Co-expressions between TUBB3 and STMN1 are strongly demonstrated, and high expression of TUBB3 always exists as well as high expression of STMN1 (P=0.006). Meanwhile mutation of EGFR E21 is negatively correlated with TUBB3, and wild type of EGFR E21 always exists toghther with high expression of TUBB3 (P=0.004,6), whereas mutation of KRAS E2 is positively associated with expression level of STMN1 (P=0.038,6)., Conclusion: Antimicrotubule drug resistance factors of TUBB3 and STMN1 may be related with mutations of EGFR signal pathway, suggesting that EGFR mutation and KRAS mutation may be important factors in regulation of TUBB3/STMN1 expression, which provided basic references for chemotherapeutic resistance.

Objective: To detect K-ras gene mutations in plasma free DNA by peptide nucleic acid clamp PCR assay (PNA-PCR) and nested primer PCR, and to analyze the correlation between K-ras mutations and prognosis in patients with metastatic colorectal cancer (mCRC)., Methods: Peripheral blood was collected and free DNA was extracted from plasma in 106 patients with mCRC. Nested primer PCR and PNA-PCR were used to detect K-ras gene mutation in the plasma free DNA. The patients were divided into three groups by K-ras status: wild-type group (wild-type determined by both methods), low mutation group (mutation by PNA-PCR method, wild-type by nested primer PCR method) and high mutation group (mutation by two methods). The correlation between K-ras mutations and prognosis was analyzed., Results: The mutation rate of K-ras in tumor tissues of the 106 patients was 40.6%. The Mutation rate of K-ras in plasma free DNA detected by PNA-PCR was 31.1%, significantly higher than that of 15.1% detected by nested primer PCR (P = 0.006). The consistent rate of the K-ras status in plasma free DNA detected by PNA-PCR and that in tumor tissue detected by traditional method was up to 83.0%. The median overall survival (OS) of patients of the wild type, low mutation and high mutation groups was 23.5 months, 17.3 months and 13.9 months, respectively (P = 0.002). The median progression-free survival (PFS) of the K-ras wild-type, low mutation and high mutation groups with first-line chemotherapy was 6.8 months, 6.1 months and 3.2 months, respectively (P = 0.002), and the median OS of them were 23.0 months, 15.5 months and 13.9 months, respectively (P = 0.036). The overall response rate (ORR) was improved in the K-ras wide-type patients who received cetuximab combined with chemotherapy as first-line therapy (75.0% vs. 23.4%, P = 0.058). Cetuximab combined with in second-line therapy chemotherapy led to a significant improvement in disease control rate (DCR) ( 100% vs. 35.7%, P < 0.001) as compared with those of chemotherapy alone. COX regression model showed that K-ras status detected by PNA-PCR, ECOG PS, number of surgery and initially metastatic site were independent factors for prognosis., Conclusions: PNA-PCR for the detection of K-ras mutation in plasma free DNA can be used to substitute the traditional method for detection of K-ras mutation in tumor tissues. The abundance of K-ras mutation in plasma free DNA is an independent prognostic factor for patients with metastatic colorectal cancer.

Ras is best known for its ability to regulate cell growth, proliferation and differentiation. Mutations in Ras are associated with the abnormal cell proliferation which can result in incidence of all human cancers. Extracellular signal-regulated kinase (ERK) is a downstream effector of Ras and plays important roles in prognosis of tumors. Recently, evidence has gradually accumulated to demonstrate that there are other effectors between Ras and ERK, these proteins interact each other and constitute the thorough Ras/Raf/MEK/ERK signaling pathway. The pathway has profound effects on incidence of esophageal carcinoma and clinical applications of some chemotherapeutic drugs targeting the pathway. Further understanding of the relevant molecular mechanisms of Ras/Raf/MEK/ERK signaling pathway can be helpful for the development of efficient targeting therapeutic approaches which contribute to the treatment of esophageal cancer. In this article, roles of Ras/Raf/MEK/ERK signaling pathway in esophageal carcinoma as well as pharmacological targeting point in the pathway are reviewed.

Objective: To elucidate the role of let-7d in regulating the biological behavior of ovarian cancer cells and their expressions of HMGA2 and ras proteins., Methods: The pre-let-7d sequence was synthesized and inserted into pcDNA6.2GW/EmGFPmiR and transfected into ovarian cancer IGROV1 cells to cause pre-let-7d overexpression. Real-time quantitative RT-PCR was employed to examine the expression levels of let-7d miRNA and HMGA2 mRNA, and Western blotting was performed to detect the expressions of HMGA2 and ras protein in the transfected cells. The effect of pcDNA6.2GW-let-7d transfection on IGROV1 cell proliferation was determined using MTT assay and the cell apoptosis rate was measured using flow cytometry., Results: The eukaryotic expression vector containing the target gene let-7d was successfully constructed and transfected into IGROV1 cells. The transfected cells showed a marked reduction of HMGA2 expression but a less obvious down-regulation of ras expression. Transfection with pcDNA6.2GW-let-7d to suppress the expression of HMGA2 caused alterations of the phenotype of IGROV1 cells shown by a reduced proliferative activity and increased cell apoptosis., Conclusion: Let-7d plays an important role in altering the malignant cell phenotype of ovarian cancer IGROV1 cells by regulating the expression of HMGA2.

Objective: To determine the association between activity of BRAF and mitogen-activated protein/ extracellular signal-regulated kinase kinase (MEK) / extracellular signal-regulated kinase (ERK) signal pathway in papillary thyroid cancer and its mechanism., Methods: We collected the clinical data and blood samples from 73 cases of papillary thyroid cancer and another 16 cases of benign thyroid gland tumor, and detected the expression of rat sarcoma (RAS), BRAF, MEK1/2, and ERK1/2 in all tumor specimens and benign thyroid tissues with immunohistochemistry and Western blot., Results: The expression of RAS, BRAF, pMEK1/2, and pERK1/2 protein in papillary thyroid cancer tissues was higher than those in the benign thyroid tissues(P<0.05 or P<0.01). The expression of RAS, BRAF, MEK1/2, and ERK1/2 was associated with the tumor size, the lymph node metastasis, and the clinical stage of papillary thyroid cancer(P<0.05 or P<0.01)., Conclusion: The expression of RAS, BRAF, pMEK1/2, and pERK1/2 is associated with the pathogenesis, the lymph node metastasis, and the clinical stage of papillary thyroid cancer. The MEK/ERK signaling pathway may be activated by BRAF in papillary thyroid cancer.

Objective: To investigate the relationship between the expression of ERCC1, BRCA1, β-tubulin and K-ras and the clinical efficacy, prognosis in advanced non-small cell lung cancer treated by platinum-based chemotherapy., Methods: Expression of ERCC1, BRCA1, β-tubulin and K-ras proteins were detected by immunohistochemistry in 136 patients. The relation between gene protein expression and efficacy, prognosis was analyzed., Results: (1) The efficacy of chemotherapy (ORR) in the ERCC1 negative group was better than that in the ERCC1 positive group (38.6% vs.26.4%, P < 0.017). The median survival time in the ERCC1 negative group was longer than that in the ERCC1 positive group (15 months vs. 12 months, P < 0.05). There was no significant difference in PFS. (2) The clinical stage in the BRCA1 negative group was earlier than that of positive group. There was no significant difference in ORR in either the BRCA1 negative group or BRCA1 positive group. But both MST and PFS in the BRCA1 negative group was longer than that in the BRCA1 positive group (16 months vs. 9 months, P < 0.05 and 7 months vs. 7 months, P < 0.05), respectovely. (3) There were no significant differences between the β-tubulin negative group and positive group in MST, PFS and ORR. (4) The ORR in the K-ras negative group was better than that in the K-ras positive group. There was no significant difference between the K-ras negative and positive groups in MST and PFS. (5) ERCC1 protein was an independent prognostic factor determined by multivariate analysis., Conclusions: Multi-biomarker detection may provide important predictive value for chemotherapy efficacy and prognosis in advanced NSCLC.

Objective: To study the efficacy and safety of cetuximab combined with chemotherapy for patients with advanced colorectal cancer (ACRC) and unclear K-ras status., Methods: Clinical data of 102 ACRC patients, treated by cetuximab combined with chemotherapy in Sun Yat-sen Cancer Center from March 2005 to December 2008, were collected. The cumulative survival rate, objective response rate (ORR), disease control rate (DCR), progression free survival (PFS) of the cases were calculated. The difference in ORR, DCR, PFS and oval survival (OS) between the regimens used as first-line and non-first-line treatment, and between the regimens including oxaliplatin and irinotecan were compared., Results: The overall ORR of cetuximab plus chemotherapy was 43.1%, DCR 73.5%, median PFS 4.0 months, OS 28.5 months, and the 1-year, 3-year, and 5-year survival rate was 89.2%, 50.9% and 27.5%, respectively. The differences in ORR (50.0% vs. 40.0%, P = 0.344), DCR (78.1% vs. 72.9%, P = 0.571) and OS (51.0 months vs. 35.0 months, P = 0.396) between the regimens as first line and as non-first line treatment were not statistically significant. However, the PFS of the regimen as first-line was longer than that as non-first-line treatment (PFS 5.5 months vs. 3.0 months, P = 0.001). The differences in ORR (54.2% vs. 40.0%, P = 0.223), DCR (79.2% vs. 74.7%, P = 0.654), PFS (5.0 months vs. 3.0 months, P = 0.726) and OS (36.0 months vs. 40.0 months, P = 0.759) between cetuximab plus oxliplatin and irinotecan were not statistically significant. The most common side effects of cetuximab plus chemotherapy were acneiform eruption (80.4%, grade 3-4 in 9.8%), neutropenia (66.7%, grade 3-4 in 18.6%), and diarrhea (19.6%, grade 3-4 in 5.9%). No treatment-related death was recorded., Conclusion: Patients with advanced colorectal cancer and unclear K-ras treated by cetuximab combined with chemotherapy have good ORR and OS, and the regimen is safe with less adverse events for them. There is no significant difference between the efficacies of regimens as first line and as non-first line treatment, and between cetuximab plus oxliplatin and cetuximab plus irinotecan regimens.

Objective: To investigate the mechanism of influence of phosphoprotein associated with glycosphingolipid microdomains 1 (PAG1) on the biological behavior of human prostatic cancer cell line PC-3M-1E8., Methods: The expression of GST-Raf1-RBD recombinant protein, a specific binding domain of active Ras (GTP-Ras), was induced by IPTG in JM109 bacterium. SDS-PAGE and coomassie brilliant blue staining were performed using cleaved product of the bacterium to determine the expression of the fusion protein. GST-pull down essay was designed to detect the level of active Ras in PGA1 and vector transfected, respectively and in the native PC-3M-1E8 cells. Western blotting was used to detect the expression levels of downstream proteins of Ras signal pathway which may be related to the function of PAG1. Phalloidine labeled by tetramethylrhodamine-5-(and-6) isothiocyanate (TRITC) was used for the staining of intracellular F-actin, Laser passing confocal microscopy was adopted for observing change of the cell morphology and the arrangement of F-actin., Results: After IPTG induction, the GST-Raf1-RBD recombinant protein, with a molecular weight of 33 000, was noticed to be highly expressed in JM109 bacterium. GST-pull down assay revealed that the expression level of active Ras markedly decreased after PAG1-transfection while the total Ras remained unchanged. The expression of p-ERK and cyclin D1 in the PAG1-transfected cells decreased in accordance with the level of active Ras. However, the expression of p21(WAF1/CIP1) and p-Akt didn't show any variation. Additionally, the structure of F-actin was turbulent and the pseudopodia of cells diminished conspicuously after PAG1-transfection. There was a high expression of PAG1 in normal human prostate tissue, however, the positive rate of PAG1 immuno-staining decreased in cases of prostatic adenocarcinoma, correspondent with increasing of the grading index of cell differentiation established in the Gleason grading system for the diagnosis of prostate adenocarcinoma., Conclusions: An over-expression of PAG1 in PC-3M-1E8 cells effectively suppresses the activation of Ras and ERK, as well as the cyclin D1 expression, leading to an inhibition of the proliferation ability of tumor cells. The turbulence of F-actin and reduction of pseudopodia of cells result in an impairment of cell mobility, invasiveness and metastatic capability. In human prostate and prostatic adenocarcinoma tissues, the expression of PAG1 is related to the cellular differentiation and malignancy.

Background and Objective: Epidermal growth factor receptor (EGFR) and KRAS status were particularly critical for the choice of first-line targeted therapy of non-small cell lung cancer (NSCLC), while the primary tumor and metastases might be different in the EGFR and KRAS gene status. The aim of this pooled analysis is to compare EGFR and KRAS status in matching primary NSCLC and metastases and further to guide clinical practice., Methods: Systematic computerized searches of the Pubmed and Medline databases (up to May 10, 2010) meeting specified search criteria were performed, followed by a further screening according to inclusive and exclusive criteria., Results: Fourteen articles were selected into the final meta-analysis with paired primary and metastatic cases of 598. Expression level of EGFR protein and mutation frequency of KRAS gene in primary tumors were higher than that in metastases, relative risk (RR)=1.13 (95%CI: 0.98-1.31, P=0.09) and RR=1.39 (95%CI: 0.95-2.03, P=0.09), respectively. EGFR gene copy number in metastases was higher than that in primary tumor, RR=0.74 (95%CI: 0.53-1.02, P=0.06). There was no statistically significant difference of EGFR mutation frequency in primary tumors and metastases (P=0.31). The discordant rate in primary and metastases was 17.09% for EGFR mutation, 27.07% for EGFR amplification, 27.84% for EGFR protein expression and 25.91% for KRAS mutation., Conclusions: The systematic analysis showed that the EGFR mutation status in primary lung cancer and corresponding metastases was more stable than KRAS gene. KRAS mutation in primary lung cancerous foci seems to better reflect systemically cancerous genetic characteristics of KRAS gene. Determination of KRAS gene status based merely on metastatic foci might lead to more resistant selections of EGFR tyrosine kinase inhibitor (TKI) therapy. Combined detection of EGFR and KRAS mutation from primary NSCLC foci might serve as a better predictive biomarker for anti-EGFR targeted therapy.

Objective: To investigate the action targets of ginseng (GS) and Panax notoginseng (PN), Chinese herbs for benefiting qi and activating blood circulation, on angiogenesis signaling pathway (VEGFR-2-Ras-MAPK) in human umbilical vein endothelial cells (HUVEC)., Methods: To block the signal pathway by turns, at the first, added the IC50 of VEGFR-2 inhibitor, SU5416, and detected its downstream signaling protein Ras, MAPK expression using Western Blot. Secondly, added the IC50 of the Ras inhibitor, FPP, and detected its downstream signaling protein MAPK expression., Results: Compared with the control group, adding SU5416 made the Ras, MAPK expression significantly decreased (P < 0.05, P < 0.01); and adding FPP made the expression of MAPK significantly decreased (P < 0.01). Compared with the group treated by SU5416 alone, the expression of downstream signaling protein Ras, MAPK were significantly higher in the group treated by SU5416 plus GS and PN (P < 0.05, P < 0.01); same state also found in comparison MAPK expression between groups treated with FPP alone and FPP plus GS and PN (P < 0.05)., Conclusion: The angiogenesis mechanism of GS and PN on HUVEC may be realized by increasing the protein expression of three key signals, VEGFR-2, Ras and MAPK, respectively.

Objective: To study the action mechanism of Yiqi Yangyin Recipe (YYR) in treating leukemia by observing the effects of YYR and its different assembling, energy supporting part (P1) and evil dispelling part (P2) on expressions of Flt3 and N-ras gene in acute myeloid leukemic (AML) cells., Methods: The mononuclear cells collected from bone marrow of 60 AML patients were assigned to four groups: the blank was untreated for control and the three tested groups were treated with YYR, P1 and P2, respectively. The effects on Flt3 and N-ras gene expressions and FLT3 protein expression were observed by RT-PCR and Western bloting., Results: RT-PCR test showed the expression of Flt3 in the control, YYR, P1 and P2, group was 90.78% +/- 6.92%, 38.18% +/- 4.50%, 65.57% +/- 5.55% and 61.35% +/- 6.39%, respectively; and that of N-ras in them 93.28% +/- 5.54%, 34.38% +/- 6.69%, 59.42% +/- 7.35% and 65.28% +/- 7.64%, respectively, both showed significant difference as compared the data in the tested groups with those in the control group (P < 0.05). Western bloting test showed the FLT3 protein gray value in the four groups was 0.8127 +/- 0.0284, 0.4265 +/- 0.0353, 0.5396 +/- 0.0274 and 0.5473 +/- 0.0282, respectively, also showed significant difference between the control and the tested groups (P < 0.01)., Conclusion: YYR can inhibit the colonic proliferation of AML cells, decrease the expressions of FLT3 and N-ras in cells, therefore shows a therapeutic effect on AML.

Objective: To investigate the effect of over expression of human hyperplasia suppressor gene (HSG) on proliferation, invasion, apoptosis and cell cycle of human breast cancer cells and to determine the relationship between HSG and Ras-dependent signaling pathway., Methods: Full length HSG coding sequences were cloned into plasmid pcDNA3.0. The recombinant plasmids were transfected into MDA-MB-231, a highly malignant breast cancer cell line. Vacant pcDNA3.0 was used as the control. MTT, Matrigel transwell assay and flow cytometric analysis were used to test for proliferation, invasion, cell cycle distribution and apoptosis of tumor cells after transient transfection of HSG.GST-pulldown and Western blotting assays were performed to investigate the activity of Ras protein., Results: HSG transfection inhibited proliferation of MDA-MB-231 cells, and significantly decreased the number of invading cells in Matrigel transwell assay compared with the vector/231 group (78.5 +/- 5.8 vs. 131.1 +/- 14.5) cells. FACS analyses demonstrated that compared with the vector/231 group, up-regulation of HSG promoted breast cancer cell apoptosis [(35.8 +/- 4.8)% vs. (25.6 +/- 3.5%)] and induced G(0)/G(1) phase arrest [(56.3 +/- 2.3)% vs. (50.4 +/- 1.9%)] after transfection for 18 hours. Furthermore, GST-pulldown assay showed that over-expression of HSG remarkably decreased the activity of Ras (about 65% lower than control)., Conclusions: HSG exibits multiple anticancer functions in breast cancer cells including inhibition of proliferation and in vitro invasion, G(0)/G(1) arrest and promotion of apoptosis. Besides, inhibition of Ras-dependent signaling pathway may be involved in these processes.

Objective: To investigate the effects of triptolide on proliferation and regulation of ras-MAPKs pathway in human fibroblast-like synoviocytes of rheumatoid arthritis (RA-HFLS) treated with tumor necrosis factor (TNF-alpha)., Method: RA-HFLS were cultured with TNF-alpha in the presence or absence of variable doses of triptolide (0.28, 2.8, 28, 140 nmol x L(-1)) in vitro. Cell proliferation was evaluated by MTS assay. The phosphorylation status of Ras-MAPKs-associated proteins (Ras, p-P38, p-ERK and p-JNK) were detected by Western blot analysis., Result: Triptolide could obviously decrease the RA-HFLS viability in a dose-dependent manner and the inhibition ratio was 0.28%, 5.05%, 30.83% and 43.77% respectively. In addition, triptolide could also suppressed the expression of Ras, p-P38, p-ERK and p-JNK., Conclusion: Triptolide has an notable inhibiting effect on proliferation of RA-HFLS and the molecule mechanism is due in part to the direct suppression of abnormal activation of Ras-MAPKs pathway.

Ras signaling pathway is closely related to the formation and growth of tumor. Currently, targeting on this signaling pathway is a hot research point for the design and development of anticancer drugs. In this paper, Ras protein as well as its related targets and inhibitors in signaling pathway were reviewed. It is expected to give research-related reference materials for the design of new anticancer drugs.

Objective: To investigate the effect of microRNA143 on cell proliferation and K-ras expression in colorectal carcinoma., Methods: Northern blot was used to examine the expression of miR-143 in colorectal carcinoma and adjacent normal tissues. A miR-143 expression vector was constructed and transfected into a human colon adenocarcinoma cell line SW480. Cell proliferation was evaluated by MTT assay. RT-PCR and Western blot were used to examine the expression of K-ras oncogene in transfected cells., Results: The level of mature miR-143 was lower in tumors compared with adjacent normal tissues in 81% of colorectal carcinoma specimens. In transfected cells, the increased accumulation of miR-143 inhibited the cell proliferation, and resulted in approximately 40.3% decrease of K-ras protein levels, but had no effect on level of K-ras mRNA., Conclusion: The increased accumulation of miR-143 inhibits the proliferation of transfected cells, and results in down-regulation of K-ras protein in colorectal carcinoma.

Objective: To explore the expression of Ras family gene in the malignantly transformed human bronchial epithelial cell line induced by anti-benzo(a)pyrene-trans-7,8- dihydrodiol-9,10-epoxide(BPDE)., Methods: The levels of H-Ras, K-Ras and N-Ras mRNA expression in BPDE transformed 16HBE cells (16HBE-T) and untransformed control 16HBE cells (16HBE-N) were examined using RT-PCR. Expression levels of those three proteins in both kinds of cells were analyzed by western blot and immunocytochemical method., Results: Compared with 16HBE-N, the levels of H-Ras, K-Ras and N-Ras mRNA expression were significantly increased to 2.237, 1.254 and 3.616 times in 16HBE-T, and the protein levels of those genes were increased to 1.273, 1.547 and 1.600 times, respectively. Immunocytochemical method showed expression levels of those proteins in 16HBE-T were significantly higher than those in 16HBE-N., Conclusion: H-Ras, K-Ras and N-Ras are overexpressed in 16HBE-T. The activation of oncogenic Ras may participate in malignant transformation of 16HBE induced by BPDE.

Background & Objective: Point mutation of K-ras gene and overexpression of insulin-like growth factor receptor type 1 (IGF-IR) may contribute to the progression and aggressiveness of pancreatic cancer. Antisense oligodeoxynucleotide (ASODN) against K-ras mRNA and IGF-IR mRNA may inhibit the proliferation of pancreatic cancer cells. This study was to investigate the combinational effects of K-ras ASODN and IGF-IR ASODN on proliferation and apoptosis of human pancreatic cancer Patu8988 cells in vitro and in vivo., Methods: K-ras gene point mutation in Patu8988 cells was detected by polymerase chain reaction using special sequence primers (PCR-SSP) and sequence analysis. According to the mutation style, K-ras ASODN was designed and composed. K-ras ASODN and IGF-IR ASODN were transfected into Patu8988 cells alone or in combination. Cell proliferation was analyzed by MTT and colony forming assay. The morphologic changes of Patu8988 cells were assessed under transmission electron microscope. The expression of K-ras and IGF-IR mRNA and protein in Patu8988 cells was measured by reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometry (FCM). Cell apoptosis was determined by FCM. The combinational antitumor activity of K-ras ASODN and IGF-IR ASODN was evaluated in BALB/c nude mice bearing human pancreatic cancer inoculated with Patu8988 cells., Results: The point mutation of K-ras gene at codon 12 was detected in Patu8988 cells, and the mutation style was GGT-->GTT. Either 2-32 microg/mL K-ras ASODN or IGF-IR ASODN inhibited proliferation and induced apoptosis of Patu8988 cells. This effect was more obvious when K-ras ASODN and IGF-IR ASODN were used in combination than used alone (P<0.01). In tumor-bearing mice, the inhibitory effect on the growth of transplanted pancreatic cancer was more obvious when K-ras ASODN and IGF-IR ASODN were used in combination than used alone (P<0.01)., Conclusion: K-ras ASODN combined with IGF-IR ASODN could cooperatively inhibit the proliferation of Patu8988 cells and induce their apoptosis via down-regulating K-ras and IGF-IR expression.

Intracellular signal transduction plays an important role in the process of cellular metabolism, segmentation, differentiation, biological behaviour and cell death. Overactive signal transduction relates to tumor development and progression. Signaling pathways operated by protein tyrosine kinases (PTKs) will be illuminated here briefly. The Ras/Raf/MAPK and PI-3K/Akt pathways through receptor protein tyrosine kinases (RTKs), the Src, Bcr-Abl and JAK/STAT pathways by non-receptor protein tyrosine kinases (nrPTKs) are shown separately. Antitumor agents targeting the key proteins involved in the above five signalling routes are also summarized in this review.

Objective: To investigate the changes of TrkB and Ras-MAPK in brain-derived neurotrophic factor (BDNF) protecting the embryonic rat cerebral cortical neurons against hypoxia-induced neurotoxicity., Methods: The immunofluorescence technique, laser scanning confocal microscope and half-quantitative analysis were done to explore the changes of the intracellular levels of tyrosine kinase B (TrkB), phosphorylated TrkB and the mitogen-activated protein kinase (MAPK) in rat embryonic cortical neurons cultured in different time groups of hypoxia with or without BDNF pretreatment., Results: The fluorescent intensity of TrkB and phosphorylated TrkB in the cytoplasm and the fluorescent intensity of MAPK in both cytoplasm and cell nucleus of the neurons were significantly increased in the presence of BDNF (P < 0.05), the fluorescent intensity of neurons pretreated with BDNF 24 h before the hypoxia culture was stronger than those with BDNF just before the hypoxia culture (P < 0.05)., Conclusion: The Ras-MAPK approach may be the major signal transferring way of BDNF in protecting the cortical neurons from hypoxia-induced neurotoxicity. The approach of signal transferring begins with tyrosine phosphorylation of TrkB receptors.

Objective: To study the inhibitory effect of mutant K-ras gene depletion by small interfering RNA on the growth of lung cancer cell line-H441 cells in vitro and in vivo., Methods: One pair of 63 bp reverse repeated sequence targeting mutant K-ras(V12) mRNA spaced by 9 bp nucleotide were synthesized and inserted into plasmid pSilencer3.1 eukaryotic expression vector. After transient and stable transfection into H441 cells, the mutant K-ras mRNA and protein level were measured by RT-PCR and Western blotting, and the H441 cells proliferation was measured by MTT method, and the apoptosis rate was detected by flow-cytometry. H441 cells treated with pSilencer3.1-K-ras(V12) were transplanted subcutaneously in nude mice and their tumorigenesis ability was observed., Results: The recombinant plasmid pSilencer3.1-K-ras(V12) was successfully constructed by sequencing. The introduction of pSilencer3.1-K-ras(V12) was showed to efficiently and specifically inhibit the expression of K-ras(V12) gene according to the results of RT-PCR and Western blotting (P < 0.01, as compared with controls). The inhibitory effect on cell proliferation was confirmed by MTT test (P < 0.05, as compared with controls). Apoptosis rate of H441 cells treated with pSilencer3.1-K-ras(V12) was significantly higher than that of the control cells (P < 0.01). The test in vivo showed that downregulation of K-ras(V12) expression in H441 cells apparently affected their ability to form tumors in nude mice., Conclusions: siRNA targeting mutant K-ras mRNA can specifically suppress the expression of mutant K-ras gene in H441 cells, and therefore has a substantially inhibitory effect on cell proliferation in vitro and in vivo, it provides a new method and material to the gene therapy of lung cancer.

The ras family of proto-oncogenes are upstream mediators of several essential cellular signal transduction pathways involved in cell proliferation and survival. Point mutations of ras oncogenes result in constitutive activation of oncogenic Ras. The key step in post-translational processing of Ras protein is farnesylation by farnesyl transferase. Inhibitors of this enzyme were developed initially as a therapeutic strategy for Ras-mutated tumors. Moreover, it is now clear that farnesyl transferase inhibitors (FTIs) have activity independent of Ras, and show some effects on tumors without oncogenic ras mutations. Preclinical data show that FTIs can inhibit proliferation of breast cancer cells in vitro and in vivo, and phase II studies of FTI-R115777 in advanced breast cancer show encouraging results. Therefore, FTIs, used alone or with other agents, may be a novel therapeutic approach for breast cancer.

Background & Objective: Since most tumor antigens are uncertain, the immunotherapy against tumors still lingers in clinical trials. Because k-ras proto-oncogene specifically expresses in pancreatic cancer cells with constant mutation site, it may be an ideal target for immunotherapy against pancreatic cancer. This study was to evaluate the feasibility of inducing immunotherapy on pancreatic cancer by K-ras mutated peptides, give experimental evidence to clinical individual therapy on pancreatic cancer., Methods: k-ras oncogene was amplified by reverse transcription-polymerase chain reaction (RT-PCR)u its mutation type was detected by flow cytometry. T cells were induced by dendritic cells, which had been pulsed with synthesized mutated peptide. Killing effect of tumor specific T cells on pancreatic cancer cell line Patu8988 was assessed by MTT assay., Results: There was a point mutation (GGT-->GTT) in the 12th codon in Patu8988 cellu the amino acid was mutated to valine. The mutation epitope was efficiently presented on dendritic cells'surface. The cytotoxic T cells induced by mutated peptide could kill Patu8988 cells efficiently., Conclusions: The mutated peptide can efficiently induce immunocytes to kill pancreatic cancer cells, which have k-ras mutation site. This finding provides experimental clue for immunotherapy against pancreatic cancer.

Background & Objective: Oxidative DNA damage plays an important role in carcinogens-induced carcinogenesis. 8-hydoxy-2deoxy-guanosine (8-OH-dG), a biomarker of oxidative DNA damage, plays important roles in initiation, progression, and prognosis of lung cancer, and closely relates with mutations of k-ras and p53 genes in carcinogenesis of lung tissue. This study was to detect protein expressions of 8-OH-dG, k-ras, and p53 genes in lung cancer tissues, and to analyze their values in distinguished diagnosis of lung cancer., Methods: Protein levels of 8-OH-dG, k-ras, and p53 in pleural effusion cells from 53 patients with lung cancer, and 53 patients with other benign lung diseases were detected by immunocytochemistry., Results: Positive rates of 8-OH-dG, k-ras, and p53 protein in cancer group were significantly higher than those in benign disease group [75.5% (40/53) vs. 15.1% (8/53), P < 0.01; 64.2% (34/53) vs. 3.8% (2/53), P < 0.01; and 69.8% (37/53) vs. 18.9% (10/53), P < 0.01; respectively]. Protein levels of 8-OH-dG, k-ras, and p53 protein in cancer group were 1.68+/-1.21, 1.32+/-1.06, and 1.57+/-1.15,respectively. Rank correlation analysis showed that protein expression of 8-OH-dG positively correlated with those of k-ras (RS=0.643, P < 0.01), and p53 (RS=0.827, P < 0.01)u protein expression of k-ras positively correlated with that of p53 (RS=0.897, P < 0.01)., Conclusions: Protein expressions of 8-OH-dG, k-ras, and p53 are up-regulated in pleural effusion cells of lung cancer, and have mutual relations. They may be used as reference markers in diagnosing and screening for lung cancer.

To investigate the relationship among 8-OH-dG and the development of human lung cancer and cancer related genes, an 8-OH-dG-specific monoclonal antibody and biotin-streptavidin immuno-staining were used to detect the 8-OH-dG in 150 cases of human lung cancer tissues, 120 adjacent lung tissues without cancer cells, 40 benign lung lesions and 40 normal lung tissues. The expressions of P53, C-MYC, K-RAS, BCL-2 and hTERT(human telomerase reverse transcriptase) were determined by immunohistochemistry and the relationship among the 8-OH-dG and these genes was analyzed. The 8-OH-dG were positive in 139 of 150 (92.7%) lung cancer specimens, and the percentage of adduct labeling cell in lung cancer specimens was (24.00 +/- 25.11)% (mean +/- SE). 21 of 120 (17.5%) adjacent lung tissues were adduct positive, and the percentage of adduct labeling cell was 2.42 +/- 5.98%. 4 of 40 (10.0%) benign lung lesions were adduct positive, and the percentage of adduct labeling cell was 0.80 +/- 1.30%, whereas 2 of 40 (5.0%) normal lung tissues were weak positive with 8-oh-dG, and the percentage of adduct labeling cell in this group was (0.34 +/- 1.01)%. The level of 8-OH-dG in lung cancer tissues was significantly higher than that of adjacent lung tissues, benign lung lesions and normal lungs (P < 0.01). The lung cancer patients were stratified by sex, age, cell types and smoking history, but these characteristics were not correlated with the level of 8-OH-dG. In the investigation of the relationship between the 8-OH-dG and five cancer related genes, higher 8-OH-dG levels were observed in lung cancer patients with over-expression of K-RAS and BCL-2 than those of negative expressed patients (P-value were 0.035 and 0.034 respectively), whereas the expression of P53, C-MYC and hTERT were not correlated with level of 8-OH-dG. 8-OH-dG was an important biomarker that may reflect the oxidative DNA damages of cells, and 8-OH-dG may affect K-RAS and BCL-2 genes in the carcinogenesis of lung cancer.

Aim: To study the effect and mechanism of PD98059 on Ras-MAPK signal transduction pathway of chronic myelogenous leukemia., Methods: K562 cell line was treated by PD98059, cell viability, DNA synthesis, colony formation and MAPK activity of the treated cells were analyzed., Results: The cell viability, DNA synthesis, colony formation and MAPK activity were significantly inhibited by PD98059 (P<0.05), and the inhibitory effect was dose dependent., Conclusion: The inhibitory effect of PD98059 was achieved by blocking Ras-MAPK signal transduction pathway which can become a new target in the treatment of CML.

Activation of G-protein coupled muscarinic acetylcholine receptors and MAPKs/ERK-1/2 has been found to inhibit neural cell apoptosis and promote neural cell survival. Bcl-2 protein family also plays an important role in regulating neural cell apoptosis and survival. However, signaling pathways coupling muscarinic receptors to Bcl-2 family remains to be elucidated. In the present study, it was found that carbachol not only activated MEK/ERK-1/2 signaling pathways, but also increased the expression levels of Bcl-2 and phospho-Bad proteins in human neuroblastoma SH-SY5Y cells. These effects were blocked by a muscarinic receptor antagonist (atropine) and a MEK inhibitor(PD98059) and were significantly attenuated by a Src family kinases inhibitor(PP1) and a PKC inhibitor (bisindolymaleimide-I), but were not influenced by a G(i/o)-uncoupling reagent (pertussin toxin) and a PI-3 kinase inhibitor (wortmannin). Furthermore, carbachol also stimulated Bcl-2 promoter-driven luciferase gene expression in transfected SH-SY5Y cells. Co-transfection of Ras or Raf dominant negative mutants with the pBcl-2-Luc plasmid abolished carbachol s effects. These data suggested that muscarinic acetylcholine receptors regulated the expression of Bcl-2 protein family by Ras-ERK-1/2 signaling pathway involving the pertussin toxin-insensitive G-proteins, PKC and Src.

Background and Objective: Treatment with anti-cancer agents has failed to achieve satisfactory results in hepatocellular carcinoma. In the process of hepatocarcinogenesis, Ras has been shown to play an important role. Ras requires a farnesyl moiety for activation. It has been found that farnesyltransferase inhibitor Manumycin inhibits farnesyl protein transferase, which catalyzes farnesylation. This study was designed to investigate the antitumor effect of Manumycin in human hepatoma cell line HepG2 and try to clarify its influence on Ras pathway., Methods: The growth inhibitory effect of farnesyltransferase inhibitor Manumycin on human hepatoma cell line HepG2 was observed by using [3H]thymidine incorporation assay. The relative protein expressions of pan-Ras, N-Ras, ERK1/2, AKT, and MKP-1 affected by Manumycin were determined by using Western blot analysis., Results: Manumycin(5, 10, 20, 40, and 80 mumol/L) significantly inhibited cell growth of human hepatoma cell line HepG2 with IC50 value of (17.1 +/- 2.6) mumol/L. Manumycin could inhibit both pan-Ras and N-Ras in human hepatoma HepG2 cells, but its inhibitory effect on pan-Ras of cell membrane was much stronger. Phospho-MAPK and phospho-AKT decreased significantly after treatment of HepG2 cells with Manumycin, while total MAPK and AKT were hardly affected. After treatment with 10 nmol/L wortmannin for 1 h, which had potent inhibitory effect on phosphorylation of AKT, Manumycin had stronger inhibitory effect on phosphorylation of AKT as compared to treatment without wortmannin, eventhough AKT protein levels were still unaffected. Furthermore, the expression of MKP-1 was elevated through manumycin treatment in a concentration-dependent manner., Conclusion: Manumycin may significantly inhibit the growth of human hepatoma cell line HepG2, which was related to its inhibition on the combination of Ras and cell membrane and increasing the expression of MKP-1, accordingly inhibiting activation of ERK1/2 and AKT. These results suggest that Manumycin antagonizes the growth of HepG2 via the suppression of ras farnesylation blocking the function of oncogenic ras against and could be a potential new anti-cancer agents human cancer, including hepatocellular carcinoma.