| Cancer is a major disease that threatens public health and one of the leading cause of death worldwide. Currently,1 in 4 deaths in the world is due to cancer. For a long time, the comprehensive cancer therapy composed of primarily surgery, chemotherapy and radiotherapy is the main anticancer therapy strategy for cancer patients. Oncologists recognized that each patient with cancer is different from every other patient in clinical presentation, prognosis, tumor response and tolerance to treatment. Yet, only recently scientists and clinicians have begun to understand the biological heterogeneity of human cancer and the inter-individual variation in the human genome to enable a more personalized approach to cancer treatment--Personalized medicine,that is, to select the optimal drug and drug dosage for each patient and thereby to improve patient outcomes and minimize the harmful side effects.Chemotherapy drugs are non-specific cytotoxic drugs that damage both tumour and normal cells. So the identification and use of biomarkers which enable a more personalized approach to cancer treatment for traditional chemotherapy becomes more and more important.With the deep understanding of molecular mechanisms of tumorigenesis and the development of molecular biological technologies, the molecular targeted therapy which aim to tumor cell receptors, signaling pathway and angiogenesis molecules is an great example for the cancer personalized medicine. Molecular targeted therapy is directed at unique molecular features of cancer cells and approaches aim to produce greater effectiveness with less toxicity, which is the ideal model of anticancer therapy.So, in our current research, with the SELDI-TOF-MS method, we identified the protein biomarkers in the serum which could predict traditional chemotherapy efficiency in the most common cancers of our country-lung cancer and colorectal cancer. Also, we identified mutations of K-ras and BRAF gene in Chinese patients with colorectal cancer using pyrosequencing technology and to analyzed their relationship with various clinicopathological parameters and prognosis.Part 1 Preliminary study on the prediction model of serum protein fingerprint of the advanced CRC cancer chemotherapy efficiency.1、With the method of SELDI-TOF-MS, among the 42 patients who got benefit from the chemotherapy and 28 patients who didn’t benefit from the chemotherapy,10 protein peaks were identified (9286m/z,9431m/z,9375m/z,9298m/z,4304m/z, 9352m/z,9404m/z,4606m/z,9198m/z,3963m/z).The prediction model was constructed by the combination of these peaks,which could achieve an accuracy of 90.0% (63/70) for the chemotherapy efficiency of CRC patients. These protein peaks were higher in the chemotherapy-benefit group than the chemotherapy-non-benefit group.2、With the method of SELDI-TOF-MS, among 29 patients who got benefit from the FOLFOX chemotherapy and 15 patients who didn’t benefit from the chemotherapy, 6 protein peak were identified (9298m/z,9282m/z,4606m/z,9198m/z,7775m/ z,2266m/z). The prediction model was constructed by the combination of these peaks,which could achieve an accuracy of 88.6% (39/44) for the chemotherapy efficiency of FOLFOX in CRC patients. Among the 6 peaks, the peak 2266m/z was low expressed, while the other 5 peaks 9298 m/z,9282 m/z,4606m/ z,9198m/z,7775m/z were high expressed.3、With the method of SELDI-TOF-MS, among 13patients who got benefit from the FOLFIRI chemotherapy and 13 patients who didn’t benefit from the chemotherapy,7 protein peak were identified (mass to charge ratio 4321m/z, 4305m/z,2648m/z,2952m/z,4121m/z,4292m/z,3980 m/z). The prediction model was constructed by the combination of these peaks,which could achieve an accuracy of 92.3% (24/26) for the chemotherapy efficiency of FOLFIRI in CRC patients for the curative effect of CRC patients treated in plan. Among the7 peaks, the peak 2648m/z,2952m/z,4121m/z was low expressed, while the other 3 peaks 4321 m/z,4305m/z,4292 m/z,3980m/z were high expressed.Part 2 Preliminary study on the prediction model of serum protein fingerprint of the advanced lung cancer chemotherapy efficiency.With the method of SELDI-TOF-MS, among the 35 patients who got benefit from the chemotherapy and 12 patients who didn’t benefit from the chemotherapy,8 protein peaks were identified(mass to charge ratio4353m/z,2970m/z,2957m/z,4292m/z, 3943m/z,2961m/z,4121m/z,2000m/z). The prediction model was constructed by the combination of these peaks, which could achieve an accuracy of 95.7% for the chemotherapy efficiency of lung cancer. The expression of 2000m/z peak is lower in the chemotherapy-benefit group than the chemotherapy-non-benefit group, while the other 6 peaks(4353m/z,2970 m/z,2957 m/z,4292 m/z,3943 m/z,2961 m/z,4121 m/z) are higher expressed in the chemotherapy-benefit group. Part 3 Identification mutations of K-ras and BRAF gene in Chinese patients with colorectal cancer using pyrosequencing technology and ananlysis of their relationship with various clinicopathological parameters and prognosis.118 CRC tumor specimens were obtained from the tissue bank of Cancer Research Institute of the 2nd Affiliated Hospital of Zhejiang University College of Medicine from February 2001 to January 2005. All patients were followed up to September 2010.Forty colorectal cancer tissues were tested for K-ras mutations at codon 12 and codon 13 using polymerase chain reaction(PCR) followed by direct sequencing and pyrosequencing technology. None of K-ras mutations at codon 12 and codon 13 was detected by PCR followed by direct sequencing.A total of 41 mutations of K-ras gene were detected in our 118 patients. The total mutation rate was 34.7% (41/118). The incidence of codon 12 and codon 13 was found to be 23.7% (28/118) and 10.2% (12/118), respectively. Only one patient harboured a point mutation at codon 61 (0.8%,1/118). Of the 118 colorectal carcinomas analyzed, only 2 patients (1.7%,2/118) harboured a detectable mutation at the codon 600 in the exon 15 of BRAF gene.Gender showed an obvious relationship with K-ras gene mutation. Female patients had a higher prevalence of gene mutation than male patients (44.7%vs 28.2%, p=0.037). The K-ras mutation frequency in rectum was higher in female than male patients (34.0% vs 11.2%, p＜0.05). Male patients had a higher mutation frequency in colon than female patients (16.9% vs 10.6%, p＜0.05)Patients with wild-type K-ras gene had a median survival of 84.0 months, which was a little longer than those patients with a mutated K-ras gene whose median survival was 63.0 months. But statistic difference was not obvious (p=0.25). The patients with a mutation at codon 12 and codon 13 had a median survival of 45.0 months and 63.0 months, respectively. The only patient harbouring a mutation at codon 61 had a rather long survival of 73.0 months. There was no significant correlations between the presence of K-ras mutations (codons 12,13 and 61) and survival.Conclusion:1、The prediction model combined of 10 protein peaks (9286m/z,9431m/z,9375m/z, 9298m/z,4304m/z,9352m/z,9404m/z,4606m/z,9198m/z,3963m/z) could be used for prediction of the chemotherapy efficiency of CRC patients with accuracy of 90.0%;2、The prediction model combined of 6 protein peak (9298m/z,9282m/z,4606m/z, 9198m/z,7775m/z,2266m/z) could be used for prediction of the FOLFOX chemotherapy efficiency of CRC patients with accuracy of 88.6%;3. The prediction model combined of 7 protein peaks (mass to charge ratio 4321m/z, 4305m/z,2648m/z,2952m/z,4121m/z,4292m/z,3980 m/z) could be used for prediction of the FOLFIRI chemotherapy efficiency of CRC patients with accuracy of 92.3%;4、The prediction model combined of 8 protein peaks (mass to charge ratio 4353m/z,2970m/z,2957m/z,4292m/z,3943m/z,2961m/z,4121m/z, 2000m/zcould be used for prediction of the chemotherapy efficiency of advanced lung patients with accuracy of 95.7%;5、Pyrosequencing technology is a more rapid, simple, sensitive and low-cost method for the detection of gene SNP mutation than polymerase chain reaction(PCR) followed by direct sequencing;6、K-ras gene mutation was a common event in our 118 Chinese CRC patients, with an obvious relationship with gender. Female patients had a higher prevalence of gene mutation than male patients. K-ras gene mutation seemed not to be an independent prognostic factor in CRC patients. BRAF gene was rare mutated in Chinese CRC patients. |
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