Chemosensitizing Effect of Monk Fruit Extract on Human Bladder Cancer Cells

The outcomes of chemotherapy have been unsatisfactory with the palpable side effects. We hypothesized that natural products might help improve chemotherapy with few side effects. Recently, we came across the bioactive extracts of monk fruit (Siraitia grosvenori) with anticancer activity. We then investigated if these extracts might have chemosensitizing effect to improve the efficacy of drugs clinically used today. Four different drugs, cisplatin (CPL), carboplatin (CBL), mitomycin C (MMC), and gemcitabine (GEM), were used in this study. Human bladder cancer T24 cells were treated with each drug itself or drug combined with either LLE or MOG (two types of monk fruit extracts). Cell viability was determined to assess anticancer effect and also explored the anticancer mechanism of such combinations, focusing on the status of glycolysis, cell cycle, and chromatin structure. Cell viability test showed that all drugs had anticancer activity, reducing cell viability, but only CPL showed the enhanced anticancer effect when combined with LLE (not with MOG). The rest of three drugs had no such effects with LLE or MOG. The CPL/LLE combination was found to disrupt glycolysis, by inhibiting hexokinase activity, resulted in the decreased ATP synthesis. This combination also blocked the cell cycle progression, due to a G1 cell cycle arrest. Moreover, the two epigenetic regulators, DNA methyltransferase and histone deacetylase, were inactivated with the combination, indicating chromatin modifications. Ultimately, these treated cells were found to undergo apoptosis. In conclusion, anticancer activity of CPL can be significantly enhanced with LLE. This chemosensitizing effect is attributed to the glycolysis inhibition, a G1 cell cycle arrest, and chromatin modifications, ultimately leading to apoptosis. Thus, certain natural products such as LLE could be used as an adjuvant agent in current chemotherapy, improving the drug efficacy but minimizing side effects.

THE LOCAL AND GLOBAL EXISTENCE OF THE SOLUTIONS OF HYPERBOLIC-PARABOLIC SYSTEM MODELING BIOLOGICAL PHENOMENA

The authors prove the local existence and uniqueness of weak solution of a hyperbolic-parabolic system and establish the global existence of the weak solution for this system for the spatial dimension n = 1.

Using ^(99m)Tc-MIBI to Evaluate the Effects of Chemosensitizer on P-glycoprotein in Multidrug-resistant Carcinoma Cells

To establish a method to evaluate the effects of chemosensitizer onP-glycoprotein using ^(99m)Tc-MIBI, and observe the changes of ^(99m)Tc-MIBI uptake kinetics andP-glycoprotein levels after using verapamil in MDR human breast cells MCF-7/Adr. Methods: MDR breastcarcinoma cells, MCF-7/Adr, were incubated and different protocols were performed. Protocol Ⅰ: achemosensitizer, verapamil (10 μmol/L), was added into cell culture medium, while in control group,the same volume of DMEM was given. Cells were harvested after 2 h incubation with ^(99m)Tc-MIBI.Protocol Ⅱ: Verapamil (10 μmol/L) was added into cell culture medium and incubated for 20 min, 40min, 60 min, 80 min, 8 h, 24 h, 48 h and 72 h respectively. Cells were harvested after 2 hincubation with ^(99m)Tc-MIBI. The radioactivity of the cells was measured and P-glycoproteinexpression levels were determined with immunohistochemical stain. Results: Protocol Ⅰ: After 2hincubation with verapamil the cellular uptake of ^(99m)Tc-MIBI was remarkably higher than controlgroup (t=2.33, P 【 0.05), but there was no difference in P-glycoprotein expression levels betweentwo groups (P 】 0.05). Protocol Ⅱ: In verapamil group, ^(99m)Tc-MIBI uptake was increased withincubation time prolonging (F=58.2, P 【 0.05). When verapamil incubation time surpassed 8 h the^(99m)Tc-MIBI uptake negatively correlated to the P-glycoprotein expression levels (r=-0.73, P 【0.01). However, when incubation time was less than 80 min, there was no correlation between^(99m)Tc-MIBI accumulation and P-glycoprotein levels (r=0.16, P 】 0.05). Conclusion: ^(99m)Tc-MIBImay be used to evaluate the qualitative as well as quantitative change of P-glycoprotein expressionlevels induced by the chemosensitizer, verapamil.

Downregulation of iASPP Expression Suppresses Proliferation, Invasion and Increases Chemosensitivity to Paclitaxel of Head and Neck Squamous Cell Carcinoma In Vitro

Objective Our previous study has revealed that iASPP is elevated in human head and neck squamous cell carcinoma(HNSCC)and iASPP overexpression signifcantly correlates with tumor malignant progression and poor survival of HNSCC.This study investigated the function of iASPP playing in proliferation and invasion of HNSCC in vitro.Methods HNSCC cell line Tu686 transfected with Lentiviral vector-mediated iASPP-specific shRNA and control shRNA were named the shRNA-iASPP group and shRNA-NC group,respectively.The non-infected Tu686 cells were named the CON group.CCK-8 assay,flow cytometry,transwell invasion assay were performed to detect the effects of iASPP inhibition in vitro.Results Our results demonstrated that the proliferation of shRNA-iASPP cells at the time of 72 h(F=32.459,P=0.000),96 h(F=51.407,P=0.000),120 h(F=35.125,P=0.000)post-transfection,was significantly lower than that of shRNANC cells and CON cells.The apoptosis ratio of shRNA-iASPP cells was 9.42%±0.39%(F=299.490,P=0.000),which was significantly higher than that of CON cells(2.80%±0.42%)and shRNA-NC cells(3.18%±0.28%).The percentage of shRNA-iASPP cells in G0/G1 phase was 74.65%±1.09%(F=388.901,P=0.000),which was strikingly increased,compared with that of CON cells(55.19%±1.02%)and shRNA-NC cells(54.62%±0.88%).The number of invading cells was 56±4 in the shRNA-iASPP group(F=84.965,P=0.000),which decreased significantly,compared with the CON group(111±3)and the shRNA-NC group(105±8).The survival rate of shRNA-iASPP cells administrated with paclitaxel was highly decreased,compared with CON cells and shRNA-NC cells(F=634.841,P=0.000).Conclusion These results suggest iASPP may play an important role in progression and aggressive behavior of HNSCC and may be an efficient chemotherapeutic target for the treatment of HNSCC.

Predictive value of MTT assay as an in vitro chemosensitivity testing for gastric cancer:One institution's experience

AIM:To investigate the predictive clinical value of in vitro 3-(4,5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) assay for directing chemosensitivity in patients with gastric cancer. METHODS:Results of a total of 353 consecutive patients with gastric cancer treated with MTT-directed chemotherapy or physician’s empirical chemotherapy from July 1997 to April 2003 were reviewed and analyzed retrospectively. RESULTS:The overall 5-year survival rate of MTT- sensitive group (MSG) and control group (CG) was 47.5% and 45.1%, respectively. The results of subgroup analysis with Cox proportional-hazards model were favorable for the MSG-sensitive group. However, no statistically significant difference in survival rate was observed between the two groups. CONCLUSION:Individualized chemotherapy based on in vitro MTT assay is beneficial, but needs to be confirmed by further randomized controlled trials.

Metabolomic studies of human gastric cancer:Review

Metabolomics is a field of study in systems biology that involves the identification and quantification of metabolites present in a biological system. Analyzing metabolic differences between unperturbed and perturbed networks, such as cancerous and noncancerous samples, can provide insight into underlying disease pathology, disease prognosis and diagnosis. Despite the large number of review articles concerning metabolomics and its application in cancer research, biomarker and drug discovery, these reviews do not focus on a specific type of cancer. Metabolomics may provide biomarkers useful for identification of early stage gastric cancer, potentially addressing an important clinical need. Here, we present a short review on metabolomics as a tool for biomarker discovery in human gastric cancer, with a primary focus on its use as a predictor of anticancer drug chemosensitivity, diagnosis, prognosis, and metastasis.

Role of microRNAs in gastric cancer

Although gastric cancer(GC)is one of the leading causes of cancer-related death,major therapeutic advances have not been made,and patients with GC still face poor outcomes.The prognosis of GC also remains poor because the molecular mechanisms of GC progression are incompletely understood.MicroRNAs(miRNAs)are noncoding RNAs that are associated with gastric carcinogenesis.Studies investigating the regulation of gene expression by miRNAs have made considerable progress in recent years,and abnormalities in miRNA expression have been shown to be associated with the occurrence and progression of GC.miRNAs contribute to gastric carcinogenesis by altering the expression of oncogenes and tumor suppressors,affecting cell proliferation,apoptosis,motility,and invasion.Moreover,a number of miRNAs have been shown to be associated with tumor type,tumor stage,and patient survival and therefore may be developed as novel diagnostic or prognostic markers.In this review,we discuss the involvement of miRNAs in GC and the mechanisms through which they regulate gene expression and biological functions.Then,we review recent research on the involvement of miRNAs in GC prognosis,their potential use in chemotherapy,and their effects on Helicobacter pylori infections in GC.A greater understanding of the roles of miRNAs in gastric carcinogenesis could provide insights into the mechanisms of tumor development and could help to identify novel therapeutic targets.

Cyclin Dl antisense oligodexoyneucleotides inhibits growth and enhances chemosensitivity in gastric carcinoma cells

AIM： To examine the effects of cyclin D1 antisense oligodexoyneucleotides （ASODN） on growth and chemosensitivity of gastric carcinoma cell lines SGC7901 and its mechanism. METHODS： Phosphorothioate modified cyclin D1 ASODN was encapsulated by LipofectAMINE2000 （LF2000） and transfected into cells, the dose-effect curves and growth curves were observed. 5-FU, MTX, CDDP of different concentrations were given after transfecting cells with cyclin D1 ASODN for 24 h, the dose-effect responses were observed and IC50s were calculated. The mRNA expression of cyclin D1, thymidylate synthase （TS）, thymidine phosphorylase （TP） and dihydrofolate reductase （DHFR） was detected by reverse transcription-PCR （RTPCR） at 24 h and 48 h after transfection. RESULTS： Dose-dependent inhibitory effect was caused by cyclin D1 ASODN in SGC7901 cells. Transfecting gastric carcinoma cells with 0.2 μmol/L cyclin D1 ASODN for 24 h could inhibit growth significantly and reduce expression of cyclin D1 mRNA. Cyclin D1 ASODN could increase the chemosensitivity to 5-FU, MTX, CDDP in cells, The IC50s of different chemotherapeutic agents in ASODN plus chemotherapy groups were significantly lower than those in controls. Transfection with cyclin D1 ASODN leaded to an increase in TS and DHFR mRNA and a decrease in TP mRNA as determined by RT-PCR at 24 h, the alterations were more significant at 48 h. CONCLUSIONS： Cyclin D1 ASODN can decrease mRNA expression of cyclin D1, inhibit growth and enhance the chemosensitivity by changing the expression of enzymes related to metabolism of chemotherapeutic agents in SGC7901 gastric carcinoma cells.

Elucidation of the relationship of BNIP3 expression to gemcitabine chemosensitivity and prognosis

AIM: To evaluate the significance of BNIP3 in the pathogenesis of pancreatic cancer, we analyzed the relationship between the expression of BNIP3 and survival rate of the patients with pancreatic cancer, or chemosensitivities in pancreatic cancer cell lines, particularly for gemcitabine, the first-line anti-tumor drug for pancreatic cancer. METHODS: To compare the expression level of BNIP3 with the resistance to gemcitabine, eight pancreatic cancer cell lines were subjected to gemcitabine treatment and the quantitative real-time RT-PCR method was used to evaluate BNIP3 expression. Immunohistochemical analysis was also performed using 22 pancreatic cancer specimens to study relationship between BNIP3 expression and survival rate. RESULTS: Although no significantly positive association between BNIP3 mRNA level and gemcitabine chemosensitivity was observed, pancreatic cancer cell lines that were sensitive to gemcitabine treatment tended to show high levels of BNIP3 expression. The converse, an absence of BNIP3 expression, was not correlated with gemcitabine resistance. We further compared the BNIP3 expression profiles of resected primary pancreaticcancer specimens with the prognosis of the patients, and found a tendency of favorable prognosis and low BNIP3 expression. CONCLUSION: High levels of BNIP3 expression cannot be used as one of the predicting factors for gemcitabine chemosensitivity, and some yet to be known factors will have to fill the gap for the accurate prediction of pancreatic cancer chemosensitivity to gemcitabine. However, BNIP3 expression may have an impact on prediction of prognosis of patients with pancreatic cancer.

DIFFERENCE IN BIOLOGICAL CHARACTERISTICS AND SENSITIVITY TO CHEMOTHERAPY AND RADIOTHERAPY BETWEEN INTRAHEPATIC AND EXTRAHEPATIC CHOLANGIOCARCINOMA CELLS IN VITRO

Objective To investigate and compare the biological characteristics and sensitivity to chemotherapy and radiotherapy of intrahepatic and extrahepatic cholangiocarcinoma cells in vitro.Methods The intrahepatic and extrahepatic cholangiocarcinoma cell lines were established,and cells with steady passage were chosen to study the biological characteristics including morphology,growth dynamics,chromosome,and levels of cancer antigen(CA)125,CA19-9,alpha-fetoprotein(AFP),and carcino-embryonic antigen(CEA).Meanwhile,MTT assay was used to determine the sensitivity of both kinds of cells to 6 chemotherapeutic drugs,including cisplatin,paclitaxel,harringtonine,5-fluorouracil,vincristine,and aclacimomycin,and the inhibitory rate of cells under the irradiation of 10 Gy ray was also measured.Results The intrahepatic cholangiocarcinoma cells were mostly fusiform in shape,and extrahepatic cholangiocarcinoma cells were mostly round or polygon in shape.Their doubling time was 26.3 hours and 23.1 hours,respectively.Their average number of chromosomes was 59(range,38-84)and 67(range,49-103),respectively.The chromosome karyotypes of most intrahepatic cholangiocarcinoma cells were hyperdiploid and hypotriploid,while hypertriploid was predominant in extrahepatic cholangiocarcinoma cells.The level of CA 125 in supernatant of extrahepatic cholangiocarcinoma cells increased obviously,while levels of other determined tumor markers in both kinds of cells were all within normal range.The intrahepatic cholangiocarcinoma cells were low sensitive to cisplatin and paclitaxel,but not sensitive to the other 4 chemotherapeutic drugs.The extrahepatic cholangiocarcinoma cells were high sensitive to cisplatin,but not sensitive to the other 5 drugs.Both kinds of cells had poor sensitivity to radiotherapy.Conclusions Intrahepatic and extrahepatic cholangiocarcinoma cells show differences in shape,doubling time,chromosome karyotype,tumor marker level,and chemosensitivity,whereas they both have poor radiosensitivity.Though they are similar in histopathology,they have different growth characteristics and have discrepancy in treatment and prognosis.

Low hypoxia inducible factor-1α(HIF-1α)expression in testicular germ cell tumors--a major reason for enhanced chemosensitivity?

The molecular basis for enhanced chemosensitivity of testicular germ cell tumors （GCT） has been an area of great interest, as it could potentially give us therapeutic leads in other resistant malignancies. Thus far, however, the increased sensitivity of C＆T has been variously attributed to multiple factors -- an inability to detoxify cisplatin, a lack of export pumps, an inability to repair the DNA damage, an intact apoptotic cascade and lack of p53 mutation; but a unifying underlying etiology leading to the aforementioned processes and having a translational implication has so far been elusive. Herein, we offer evidence to support a potential significant role for the previously demonstrated low hypoxia inducible factor-la （HIF-la） expression in mediating the general exquisite chemosensitivity of testicular GCT, through the aforementioned processes. This molecular mechanism based hypothesis could have a significant translational implication in platinum refractory GCT as well as other platinum resistant malignancies.

siRNA-mediated downregulation of TC21 sensitizes esophageal cancer cells to cisplatin

AIM： To determine the functional significance of TC21 in esophageal squamous cell carcinoma （ESCC）. METHODS： TC21 siRNA transfection was carried out using Hyperfectamine to knock down TC21, and tran- scripts were analyzed by reverse transcription-poly- merase chain reaction and protein by Western blotting.We demonstrated the effect of TC21 downregulation of cell signaling in esophageal cancer cells by assess- ing the phosphorylation status of its downstream tar- gets, phosphoinositide 3-kinase （PI3K）, phosphatase and tensin homolog （PTEN）, protein kinase B （pAl〈t）, nuclear factor-KB （NF-~B） and cyclinD1 using specific antibodies. Cell survival analysis after cisplatin treat- ment was carried out by cell viability assay and cell cycle analysis using flow cytometry. RESULTS： TC21 knockdown in human ESCC cell line TEl3 cells, showed only a marginal increase （14.2%） in cell death compared with control cells. The expres- sions of the signaling proteins PI3K and pAkt, transcrip- tion factor NF-KB, and cell cycle protein cyclin D1 were markedly decreased in response to TC21 downregula- tion, whereas the level of pPTEN, an antagonist of PI3K, was increased. In addition, we evaluated the potential of TC21 as a putative target for sensitizing ESCC cells to the chemotherapeutic agent cisplatin. Increased cell death （38.4%） was observed in cells treated with cis- platin after TC21 knockdown compared with cells which were treated with cisplatin alone （20% cell death）. CONCLUSION： Results suggest that TC21 mediates its effects via the PI3K-Akt pathway, NF-KB and cyclin D1, and enhances chemoresistance in esophageal cancer cells.

VHH212 nanobody targeting the hypoxia-inducible factor 1α suppresses angiogenesis and potentiates gemcitabine therapy in pancreatic cancer in vivo

Objective:We aimed to develop a novel anti-HIF-1αintrabody to decrease gemcitabine resistance in pancreatic cancer patients.Methods:Surface plasmon resonance and glutathione S-transferase pull-down assays were conducted to identify the binding affinity and specificity of anti-HIF-1αVHH212[a single-domain antibody(nanobody)].Molecular dynamics simulation was used to determine the protein-protein interactions between hypoxia-inducible factor-1α(HIF-1α)and VHH212.The real-time polymerase chain reaction(PCR)and Western blot analyses were performed to identify the expressions of HIF-1αand VEGF-A in pancreatic ductal adenocarcinoma cell lines.The efficiency of the VHH212 nanobody in inhibiting the HIF-1 signaling pathway was measured using a dual-luciferase reporter assay.Finally,a PANC-1 xenograft model was developed to evaluate the anti-tumor efficiency of combined treatment.Immunohistochemistry analysis was conducted to detect the expressions of HIF-1αand VEGF-A in tumor tissues.Results:VHH212 was stably expressed in tumor cells with low cytotoxicity,high affinity,specific subcellular localization,and neutralization of HIF-1αin the cytoplasm or nucleus.The binding affinity between VHH212 and the HIF-1αPAS-B domain was 42.7 n M.Intrabody competitive inhibition of the HIF-1αheterodimer with an aryl hydrocarbon receptor nuclear translocator was used to inhibit the HIF-1/VEGF pathway in vitro.Compared with single agent gemcitabine,co-treatment with gemcitabine and a VHH212-encoding adenovirus significantly suppressed tumor growth in the xenograft model with 80.44%tumor inhibition.Conclusions:We developed an anti-HIF-1αnanobody and showed the function of VHH212 in a preclinical murine model of PANC-1 pancreatic cancer.The combination of VHH212 and gemcitabine significantly inhibited tumor development.These results suggested that combined use of anti-HIF-1αnanobodies with first-line treatment may in the future be an effective treatment for pancreatic cancer.

Is there still a role for cytotoxic chemotherapy after targeted therapy and immunotherapy in metastatic melanoma? A case report and literature review

Metastatic melanoma has long been considered to have a very poor prognosis and to be chemo-resistant. However, a subgroup of patients with metastatic melanoma presents remarkable responses to chemotherapeutic agents, even in the absence of a response to modern targeted therapies and immunotherapies; accordingly, determining predictive biomarkers of the response to chemotherapies for metastatic melanoma remains a priority to guide treatment in these patients. We report a case study of a patient with B-Raf proto-oncogene serine/threonine kinase-mutated metastatic melanoma harbouring many genetic mutations. The patient did not respond to prior targeted therapies or immunotherapies but experienced a dramatic objective radiological and clinical response to subsequent dacarbazine-based chemotherapy. In the era of targeted therapies and immunotherapies for metastatic melanoma, cytotoxic chemotherapies may still represent an interesting therapeutic weapon in a well-deined subgroup of patients presenting with speciic genetic and molecular features.

Inhibition of Girdin enhances chemosensitivity of colorectal cancer cells to oxaliplatin

AIM: To investigate the effect of Girdin knockdown on the chemosensitivity of colorectal cancer cells to oxaliplatin and the possible mechanisms involved.

Drug resistance gene expression and chemotherapy sensitivity detection in Chinese women with different molecular subtypes of breast cancer

Objective:The aim of the study was to identify specific chemosensitivity drugs for various molecular subtypes of breast tumors in Chinese women,by detecting the expression of drug resistance genes and by using the drug sensitivity test on different molecular subtypes of breast cancers.Methods:The expression of drug resistance genes including Topo Ⅱ,GST-π,P-gp,LRP,and CD133 were detected with immunohistochemistry in a tissue microarray.Drug sensitivity tests included those for paclitaxel,epirubicin,carboplatin,vinorelbine,and fluorouracil and were conducted on primary cancer tissue cells and cell lines,including the T47 D,BT-474,and MDA-MB-231 cells and human breast cancer xenografts in nude mice.Results:The different drug resistant genes Topo Ⅱ,GST-π,P-gp,and LRP were differentially expressed among different molecular subtypes of breast cancers(P<0.05).Positive expression of CD133 was highest in basal-like breast cancer(P<0.05).Kaplan-Meier survival analysis showed that positive expressions of Topo Ⅱ and CD133 both correlated with shorter disease-free survival(DFS)(P<0.05)and overall survival(P<0.05),and positive expression of LRP correlated only with shorter DFS(P<0.05).BT-474 showed chemosensitivity to paclitaxel and epirubicin,while MDA-MB-231 showed chemosensitivities to paclitaxel,epirubicin,carboplatin,and fluorouracil(T/C≤50%).The basal-like and HER2+breast cancer primary cells showed chemosensitivities to paclitaxel and epirubicin with significant differences compared with luminal breast cancer primary cells(P<0.05).Conclusions:The differential expression of drug resistance genes and the differential chemosensitivities of drugs in different molecular subtype of breast cancers suggested that individual treatment should be given for each type of breast cancer.

MicroRNA-708 inhibits the proliferation and chemoresistance of pancreatic cancer cells

Pancreatic cancer is one of the most aggressive malignancies with poor prognosis and high mortality.Recent studies showed that microRNAs are dysregulated and involved in the initiation and progression of pancreatic cancer.In this study,we found that miR-708 was significantly downregulated in pancreatic cancer tissues and cell lines.Lentivirus-mediated overexpression of miR-708 could significantly inhibit the proliferation and invasion,while enhanced chemosensitivity to gemcitabine in both Panc-1 and SW1990 cells.Luciferase reporter assay showed that miR-708 bound the 3’-untranslated region of survivin and suppressed the expression of survivin in pancreatic cancer cells.In pancreatic cancer tissues,survivin protein was highly expressed and negatively correlated with miR-708 expression.Furthermore,the restoration of survivin expression could partially antagonize proliferation inhibition and apoptosis induction by miR-708 in pancreatic cancer cells.The Panc-1 cells with overexpression of miR-708 also showed decreased proliferation capability in nude mouse model compared with parental cells.In conclusion,our results suggest that miR-708 inhibits pancreatic cancer and could be a novel potential candidate to treat pancreatic cancer.

Enhanced chemosensitivity of p73α gene transferred into H1299 cell line of human lung adenocarcinoma

Objective: To study the effects of transferred wild type p73α gene on the sensitivity to the chemotherapeutic agents and the growth of p53-null H1299 cells of human lung adenocarcinoma. Methods: The pcDNA3-HA-p73α plasmid was transferred into the cultured p53-null H1299 cells of human lung adenocarcinoma with the mediation of Dosper liposome; The cells resistant to G418 were selected. The expression of p73α gene in the cells was examined with Western blot. MTT assay was used to analyze the response of the transfected cells to cis-dichlorodiamine platinum (cDDP) and adriamycin (ADM). The rate of drug-induced apoptosis of the transfected cells was determined with flow cytometry and DNA fragmentation assay. The changes of the biological behaviors were observed with colony formation assay. Results: The transfected H1299 cells of human lung adenocarcinoma over-expressed p73α protein stably. MTT assay showed that the IC 50 values of cDDP and ADM were reduced by approximately 7 fold and 130 fold respectively in the transfected cells as compared with the untransfected ones. Lower concentration of the chemotherapeutic agents (1.25 μmol/L of cDDP and 0.05 μmol/L of ADM) could be employed to suppress markedly the growth of the transfected H1299 cells. The apoptotic rate induced by cDDP was increased from 10.1% to 38 4% (P<0.01) and that of ADM from 12.1% to 49.3% (P<0.01). The clonogenecity after the administration of chemotherapeutic agents was significantly lower in the transfected H1299 cells than in the parental cells (P<0.01). The sensitive enhancement ratios were 1.8 and 2.6 for cDDP and ADM respectively. Conclusion: The transfection of H1299 cells with wild type p73α gene results in an increase of the sensitivity of the cells to chemotherapeutic agents.

A study of the expression of p53 in posttransfection cells with rAdp53 gene and inhibitory activity in vitro

Objective： To investigate the inhibitory effect and IC50, （rAdp53） in colorectal cancer cells in vitro and to guide （50% inhibiting concentration） of the recombinant adenoviral p53 gene clinical practice. Methods： We evaluated the efficiency （IC50）of the rAdp53 and six kinds of anti-cancer drugs（5-fluorouracil, tegafur, mitomycin c, cisplatin, oxaliplatin, paclitaxel） in human colorectal cancer cell line-174 through the cell culture and MTT chemosensitivity assay to make sure the anti-cancer capability of rAdp53. Expression of p53 protein in transfection cells of colorectal cancer line-174 with rAdp53 was evaluated by immunohistochemical staining. Results： The rAdp53 is a dose-and time-dependent anti-cancer drug, its IC50 is 5.73×10^11 VP/ml, but its effect was not obvious when compared with other anti-cancer drugs. In control group, the immunohistochemistry stain was negative. However, rAd-p53 of five different concentrations were all positive in infected colorectal cancer cells with rAd-p53 and the earliest positive result would present 24 hours after infection. Conclusion： The rAdp53 has good anti-cancer efficacy is colorectal cancer cell line-174 in vitro. But its anti-cancer efficacy was less than those of the classical chemical medicine mitomycin c, 5-fluorouracil and cisplatin etc., when it was used alone.

Chemotherapy of cerebral gliomas directed by the chemosensitivity test in vitro: a clinical study

Objective： To evaluate correlation between chemosensitivity of tumor cells in vitro and their clinical responsiveness in vivo by comparing the difference of curative effect between chemotherapy of cerebral gliomas directed by chemosensitivity test in vitro and its routine chemotherapy. Methods： Sixty-two patients with cerebral gliomas were recruited as the experiment group, who had received total resection or subtotal resection of the tumor. The resected tumor cells were cultured in vitro, followed by chemosensitivity test using colorimetric MTT assay. Finally, chemotherapeutic protocol was made based on the results of the chemosensitivity test. Fifty patients with cerebral gliomas subjected to the routine chemotherapeutic protocol were simultaneously recruited as the control group, whose age, gender, survival functional status and operational fashion were matched with the experiment group. The two groups were equally followed up for the survival functional status, recurrence and death. All data were analyzed using SPSS 10.0 software. Results： At the time of evaluation, KPS values of 64.52 ± 35.84 were seen in the experiment group, and 33.60 ± 36.24 in the control group, showing statistical difference between the two groups （t = 4.5163, P = 0.000）. During 2-4 years of follow up, a recurrence rate of 32.26% was seen in the experimental group, and 60.00% in the control group, showing a statistical difference between the two groups （X^2 = 8.620, P = 0.003）. The fatality was 22.58% in the experiment group, and 48.00% in the control group, showing a statistical difference between the two groups （X^2 = 7.978, P = 0.005）. The survival rate of the experimental group was higher than that of the control group, showing a statistical differences between the two groups （X^2= 7.29, P = 0.0069）. Conclusion： Chemotherapy of glio- mas under the guidance of chemosensitivity test in vitro contributes to obvious improvement on the current survival functional status, a clear decline of the recurrence rates and fatality rate, and raised survival rates of the patients. A close correlation between the chemosensitivity in vitro and clinical responsiveness in vivo is observed.