| Object:The brain glioma is the most common central nervous system primary tumor; the treatment of glioma is a difficult problem that has been perplexing the neurosurgery field for a long time. Especially advanced malignant glioma grows widespreadly without clear border, with, high recurrence rate of postoperative, devastating prognosis and high mortality. The biological characteristics of glioma result in combination treatment being adopted in its treatment, which predominate in surgery, with radiotherapy, chemotherapy, and immunotherapy postoperatively as complementary. The position of chemotherapy in the tumor treatment has been already clear and definite. But in clinic we find chemotherapy is often unsatisfactory in glioma, because the drug resistence gene MGMT and blood brain barrier seriously hinder chemotherapy function. We aimed to explore the effects of ACNU combined with CDDP in glioma treatment by in vitro experiment, rat glioma xenograft, and clinical data, and analyze the clinical feasibility, validity and safety of drug combination, compared with the curative effect of single drug ACNU or CDDP.Method:Clinical research; Clinical data of remedial chemotherapy cases with recurrent gliomas from2005to2012was retrospectively analyzed, and cases were divided into two groups-ACNU+CDDP group and temozolomide group. Short-term efficacy and one-year survival were compared between the two groups.Basic research: C6glioma cells were cultured into4groups at random:Control group, ACNU group, CDDP group, and ACNU+CDDP group. The amount of drug used in the experiment was developed based on the formula referring to dosage of the clinical medicine; four groups were offered chemotherapy medicine separately. Cell cycle and cell apoptosis were analyzed by flow cytometry (FCM) and Annexin V-FITC/PI. The establishment of Wistar rats with intracranial C6glioma model was confirmed successfully by Gd-DTPA enhanced MRI scan, and then rats were randomly divided into4groups as above. After continuous drug delivery for3days, some rats of each group were sacrificed, and HE staining and immunohistochemistry were used to validate the morphology of tumor tissue as well as the expression of proliferation-related protein PCNA and apoptosis-related protein bcl-2. The remaining rats were left to observe survival rates.Results:Clinical research; The short-term efficacy of combination chemotherapeutic group was evaluated according to the tumor volume appearing on the first MRI scan after chemotherapy, and the data was that14cases (56%) were PR,8cases (32%) were SD,3cases (12%) were PD, and two cases showed far metastatic focus. The short-term efficacy of temozolomide group was evaluated according to the tumor volume appearing on the MRI scan after the second chemotherapy cycle, and the data was that two cases (5.6%) were PR,26cases (72.2%) were SD, and8cases (22.2%) were PD. The short-term efficacy of combination chemotherapeutic group was significantly better than that of control group (P<0.01). All members in combination chemotherapeutic group appeared myelotoxicity with varied extent, including18neutropenia cases (72%) and14thrombocytopenia cases (56%). There were no serious myelotoxicity and liver dysfunction. In combination chemotherapeutic group, the average survival time was9.0±1.0months and one-year survival rate was28%with the initial time point set at the start of the first chemotherapy cycle. In temozolomide group, the average survival time was8.4±6.8months and one-year survival rate was19.4%with the initial time point set at the start of the first chemotherapy cycle. There was no significant difference between the above groups (P>0.05). Basic research:Cells in ACNU+CDDP group were more sensitive to treatment than other three groups, and we could see that cells died in a large amount, the surplus cell shape was obviously thin and weak. FCM analysis showed no obvious change in cell cycle of each group, but cell apoptosis rate of ACNU+CDDP group was10.10%, which increased a lot compared with others (p<0.01). Rats with C6glioma showed less activity and diet, dispirited spirit, and late dysfunction gradually. Survival time was29.41days on average. The survival analysis revealed life cycle of group ACNU+CDDP was obviously longer than that of other three groups. Pathology detection showed significant patterns of cell shapes, large nucleus with deep staining, cell polar permutation, and large areas of apoptosis and necrosis in ACNU+CDDP group. Discrete tumor foci counting analysis of the margin revealed that ACNU+CDDP group was much less than the remaining three groups, with significant statistically difference. Immunohistochemical test showed that the expression of PCNA in ACNU+CDDP group was the lowest, about44.84%and the expression of Bcl-2protein in ACNU+CDDP group was also the lowest (p <0.01).Conclusions:In this study, in clinical studies we also found that ACNU+CDDP delivering continuously for72hours could effectively inhibit tumor growth, with better short-term efficacy than temozolomide, but its severe bone marrow suppression impaired its long-term efficacy. ACNU+CDDP combination could not be able to replace temozolomide as the first-line therapy. Both cell and animal experiments showed ACNU+CDDP combination could inhibit glioma cell proliferation and promote apoptosis with higher efficiency than single drug group, which indicated that the two drug combination therapy was superior to single ACNU or CDDP treatment. Histopathology also revealed that there were a large number of tumor necrosis in the combination group, and more importantly, the number of discrete tumor foci around was significantly reduced. According to the above conclusions, we consider the possibility of ACNU+CDDP treatment as adjuvant chemotherapy prior to surgery, so as to reduce tumor recurrence rates and extend survival time. And patients with no surgery opportunities because of focus locating in the hypothalamus, brain stem, motor areas and other important functional areas could get chance to take operation. Neo-adjuvant chemotherapy may bring new hope for glioma treatment. |
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