Correlation between IL3 signaling pathway-related genes and immune checkpoint inhibitor efficacy in patients with renal cell carcinoma.

BACKGROUND: There is a lack of effective biomarkers that predict immunotherapy efficacy in clear cell renal cell carcinoma(KIRC). OBJECTIVE: We aimed to identify biomarkers that would predict the efficacy of KIRC treatment with immune checkpoint inhibitors (ICIs). METHODS: Cohort data of KIRC patients with somatic mutations, mRNA expression and survival data from The Cancer Genome Atlas (TCGA) database and immunotherapy cohort and Genomics of Drug Sensitivity in Cancer (GDSC) database were analyzed and divided into interleukin 3 (IL3) pathway-related genes high expression (IL3-High) and IL3 pathway-related genes low expression (IL3-Low) groups according to pathway expression status to assess the relationship between the IL3 pathway-related genes activation status and the prognosis of KIRC patients treated with ICIs. The data were validated by immunohistochemistry experiments, and possible mechanisms of action were explored at the level of gene mutation landscape, immune microenvironment characteristics, transcriptome and copy number variation(CNV) characteristicsRESULTS: The IL3 pathway-related genes was an independent predictor of the efficacy of ICIs in KIRC patients, and the IL3-High group had a longer overall survival (OS); KIRC patients in the IL3-High group had increased levels of chemokines, cytolysis, immune checkpoint gene expression and abundant immunity. The IL3-Low group had poor immune cell infiltration and significant downregulation of complement activation, cytophagy, B-cell activation, and humoral immune response pathways. The high group was more sensitive to targeted drugs of some signaling pathways, and its efficacy in combining these drugs with immunity has been predicted in the published literature. CONCLUSION: The IL3 pathway-related genes can be used as a predictor of the efficacy of ICIs in KIRC. The IL3 pathway-related genes may affect the therapeutic efficacy of ICIs by affecting the expression of immune-related molecules, immune cell infiltration, and the level of immune response pathways.

HER2-targeting antibody-drug conjugate RC48 alone or in combination with immunotherapy for locally advanced or metastatic urothelial carcinoma: a multicenter, real-world study.

BACKGROUND: Phase II trials showed the efficacy of anti-HER2 RC48-ADC (disitamab vedotin) for HER2-positive metastatic urothelial carcinoma (UC). This study evaluated RC48 alone verses in combination with immunotherapy for locally advanced or metastatic UC using real-world data. METHODS: This retrospective, multicenter, real-world study included patients with locally advanced or metastatic UC who received RC48 in five hospitals in China between July 2021 and April 2022. The outcomes were progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), and adverse events. RESULTS: Thirty-six patients were included. The patients were 47-87 years, and 26 (72.2%) were male. Eighteen patients received RC48 alone, and 18 received RC48 combined with a programmed death-1 antibody. The median PFS was 5.4 months. The median OS was not reached. The 6-month and 1-year PFS rates were 38.8% and 15.5%, respectively. The 1-year OS rate was 79.6%. Fourteen (38.9%) patients achieved a partial response, and the ORR was 38.9%. Eleven patients had stable disease, and the DCR was 69.4%. The median PFS for patients who received RC48 combined with immunotherapy and those who received RC48 alone was 8.5 and 5.4 months, respectively. The main treatment-related adverse events included anemia, hypoesthesia, fatigue, and elevated transaminase. No treatment-related death occurred. CONCLUSION: RC48 alone or combined with immunotherapy might benefit patients with locally advanced or metastatic UC, regardless of impaired renal function.

Long-term Follow-up of Detaenial Sigmoid Neobladder Reconstruction for Paediatric Patients with Bladder and Prostate Rhabdomyosarcoma: Technique and Results from a Single High-volume Centre.

BACKGROUND: Rhabdomyosarcoma (RMS) is the most common paediatric soft-tissue sarcoma. Approximately 15-20% of RMS cases arise from the bladder and prostate (B/P). The optimal treatment strategy for B/P RMS remains unclear. OBJECTIVE: To retrospectively evaluate the applicability of our procedure performed to treat paediatric patients with B/P RMS. DESIGN, SETTING, AND PARTICIPANTS: This is a retrospective analysis from a single tertiary referral hospital. From August 2003 to March 2021, 62 children pathologically diagnosed with B/P RMS underwent radical cystectomy and orthotopic detaenial sigmoid neobladder reconstruction in our centre. SURGICAL PROCEDURE: Surgical procedures included laparoscopic radical cystectomy and detaenial sigmoid neobladder reconstruction, which is demonstrated in the accompanying video. MEASUREMENTS: Demographic, clinical, and follow-up data were collected. Perioperative and long-term oncological and functional outcomes were reported. A logistic regression analysis was also performed. RESULTS AND LIMITATIONS: All surgeries, including three intracorporeal laparoscopic surgeries, were completed successfully. Of the 62 patients, 54 were alive without evidence of disease recurrence or metastasis at the last follow-up. Five of the 14 >12-yr-old boys reported that they experienced erections. Two female patients >12 yr old reported that they menstruated. However, this was a retrospective study conducted at a single centre with limited surgeon experience. CONCLUSIONS: Our results confirmed the safety and feasibility of primary orthotopic sigmoid neobladder reconstruction after radical cystectomy for paediatric patients with B/P RMS. Good outcomes in terms of oncological control and functional recovery were achieved. The high histocompatibility and tissue adaptability of children are inspiring. PATIENT SUMMARY: We describe our stepwise technique of radical cystectomy and detaenial sigmoid neobladder reconstruction for paediatric patients with bladder and prostate rhabdomyosarcoma. With this technique, we were able to achieve good functional recovery without compromising cancer control and significantly increasing complications.

UBE3A deletion enhances the efficiency of immunotherapy in non-small-cell lung cancer.

Immunotherapy significantly improves the prognosis of advanced lung cancer. It has become an important treatment option for advanced lung cancer. However, there remain many limitations in clinical treatment, and only a small portion of patients can benefit from immunotherapy. Our study aimed to identify markers that can precisely forecast the efficacy of immunotherapy in patients. We analyzed a non-small-cell lung cancer (NSCLC) immune checkpoint inhibitor (ICI) cohort (n=240). We used this discovery cohort to identify CNVs in genes associated with immunotherapy. We further analyzed immune biomarkers and immune infiltration in The Cancer Genome Atlas (TCGA)-NSCLC cohort and the Gene Expression Omnibus (GEO) cohorts. By analyzing an ICI dataset from MSKCC, we found that progression-free survival (PFS) was improved after UBE3A deletion (UBE3A-del). The analysis results showed that UBE3A-del had higher immunocyte infiltration levels and higher expression levels of immune checkpoint biomarkers and affected the enrichment levels of immune signaling pathways. Our results suggest that UBE3A-del can be used as a predictive biomarker of NSCLC to screen for NSCLC patients who may benefit from ICI therapy. Abbreviations: NSCLC: Non-small cell lung cancer; CNV: Copy number variation; ICIs: Immune checkpoint inhibitors; TCGA: The cancer genome atlas; GEO: Gene expression omnibus; GSEA: Gene set enrichment; PFS: Progression-free survival; OS: Overall survival; TMB: Tumor mutational burden; CTLA-4: Cytotoxic T lymphocyte antigen 4; PD-(L)1: Programmed cell death (ligand) 1; MSI: Microsatellite instability; dMMR: DNA mismatch repair; SCNAs: Somatic copy number alterations; TME: Tumor microenvironment; MSK-IMPACT: The Memorial Sloan Kettering-Integrated Mutation Profilng of Actionable; Cancer Targets; FDA: Food and Drug Administration; WES: Whole-exome sequencing; SNP: Single Nucleotide Polymorphisms; FDR: False discovery rate; DCR: Disease control rate; DDR: DNA damage response and repair; MDSCs: Myeloid-derived suppressor cells; FAO: Fatty acid oxidation.

Hypoxic Characteristic Genes Predict Response to Immunotherapy for Urothelial Carcinoma.

Objective: Resistance to immune checkpoint inhibitors (ICIs) has been a massive obstacle to ICI treatment in metastatic urothelial carcinoma (MUC). Recently, increasing evidence indicates the clinical importance of the association between hypoxia and immune status in tumor patients. Therefore, it is necessary to investigate the relationship between hypoxia and prognosis in metastatic urothelial carcinoma. Methods: Transcriptomic and clinical data from 348 MUC patients who underwent ICI treatment from a large phase 2 trial (IMvigor210) were investigated in this study. The cohort was randomly divided into two datasets, a training set (n = 213) and a testing set (n = 135). Data of hypoxia-related genes were downloaded from the molecular signatures database (MSigDB), and screened by univariate and multivariate Cox regression analysis to construct a prognosis-predictive model. The robustness of the model was evaluated in two melanoma cohorts. Furthermore, an external validation cohort, the bladder cancer cohort, from the Cancer Genome Atlas (TCGA) database, was t used to explore the mechanism of gene mutation, immune cell infiltration, signaling pathway enrichment, and drug sensitivity. Results: We categorized patients as the high- or low- risk group using a four-gene hypoxia risk model which we constructed. It was found that patients with high-risk scores had significantly worse overall survival (OS) compared with those with low-risk scores. The prognostic model covers 0.71 of the area under the ROC curve in the training set and 0.59 in the testing set, which is better than the survival prediction of MUC patients using the clinical characteristics. Mutation analysis results showed that deletion mutations in RB1, TP53, TSC1 and KDM6A were correlated with hypoxic status. Immune cell infiltration analysis illustrated that the infiltration T cells, B cells, Treg cells, and macrophages was correlated with hypoxia. Functional enrichment analysis revealed that a hypoxic microenvironment activated inflammatory pathways, glucose metabolism pathways, and immune-related pathways. Conclusion: In this investigation, a four-gene hypoxia risk model was developed to evaluate the degree of hypoxia and prognosis of ICI treatment, which showed a promising clinical prediction value in MUC. Furthermore, the hypoxia risk model revealed a close relationship between hypoxia and the tumor immune microenvironment.

Nestin is essential for cellular redox homeostasis and gastric cancer metastasis through the mediation of the Keap1-Nrf2 axis.

BACKGROUND: Gastric cancer (GC) is a common malignancy of the digestive system. Antioxidant activity is regarded as a possible mechanism in ectopic cancer. Hence, oxidative stress regulation is being evaluated for cancer treatment. Previous research has demonstrated that Nestin is associated with antioxidative resistance via its modulation of the Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. METHODS: We determined the role of Nestin-mediated redox homeostasis and tumor phenotypes in GC cells. RESULTS: We found that the Nestin expression level was high in GC tissues and cell lines. Nestin knockdown in the GC cell lines SGC-7901 and MKN-45 reduced viability, induced apoptosis, decreased antioxidant enzyme generation, and repressed GC metastasis. Nestin binds to Keap1, resulting in Nrf2 degradation and influencing downstream gene expression. Nestin knockdown resulted in the downregulation of Nrf2 expression in GC cells. The restoration of Nrf2 expression or treatment with the Nrf2 activator sulforaphane counteracted the inhibitory effect of Nestin knockdown on the proliferation, migration, invasion, and antioxidant enzyme production in GC cells. Moreover, xenograft GC tumors exhibited a slower growth rate than those of the control group in vivo. CONCLUSIONS: Taken together, these findings suggest that the Nestin-Keap1-Nrf2 axis confers oxidative stress resistance and plays an important role in the proliferation, migration, and invasion of GC cells.

High mutations in fatty acid metabolism contribute to a better prognosis of small-cell lung cancer patients treated with chemotherapy.

BACKGROUND: The majority of patients with small-cell lung cancer (SCLC) show a good response in the early stages of treatment, but more than 90% of patients will develop drug resistance. Therefore, biomarkers are urgently needed to identify patients who can benefit from systemic treatment. METHODS: We prospectively enrolled 52 extensive-stage SCLC patients before treatment from a local hospital to identify mutations related to patient prognosis, and verified them in the published Jiang's cohort and George's cohort. RESULTS: We found that patients with high mutations (mut-high) in the fatty acid (FA) metabolism pathway had a longer progression-free survival (PFS) in the local hospital cohort (HR = 0.446, 95% CI, 0.207-0.959, p = 0.0387) and a longer overall survival (OS) in Jiang's cohort (HR = 0.549, 95% CI, 0.314-0.960, p = 0.0351) than patients with low mutations (mut-low). Multivariate analysis suggested that mut-high status was an independent prognostic factor in both cohorts. George's cohort verified that mut-high status was associated with a longer OS than mut-low status (HR = 0.730, 95% CI 0.440-1.220, p = 0.2277). The possible mechanisms were as follows: the frequency of mutated FA synthase (FASN) in the mut-high group was greater than that in the mut-low group, and pathways related to the cell cycle, DNA repair, and oxidative phosphorylation were enriched in the mut-high group. CONCLUSIONS: The prognosis of SCLC patients treated with chemotherapy was better among patients with more mutations in the FA metabolism pathway, and the underlying mechanisms could be found at the genome and transcriptome levels.

Glycogen Metabolism Predicts the Efficacy of Immunotherapy for Urothelial Carcinoma.

Urothelial cancer (UC) is one of the common refractory tumors and chemotherapy is the primary treatment for it. The advent of immune checkpoint inhibitors (ICI) has facilitated the development of treatment strategies for UC patients. To screen out UC patients sensitive to ICI, researchers have proposed that PD-L1, tumor mutation burden and TCGA molecular subtypes can be used as predictors of ICI efficacy. However, the performance of these predictors needs further validation. We need to identify novel biomarkers to screen out UC patients sensitive to ICI. In our study, we collected the data of two clinical cohorts: the ICI cohort and the TCGA cohort. The result of the multivariate Cox regression analysis showed that glycogen metabolism score (GMS) (HR = 1.26, p = 0.017) was the negative predictor of prognosis for UC patients receiving ICI treatment. Low-GMS patients had a higher proportion of patients achieving complete response or partial response to ICI. After the comparison of gene mutation status between high-GMS and low-GMS patients, we identified six genes with significant differences in mutation frequencies, which may provide new directions for potential drug targets. Moreover, we analyzed the immune infiltration status and immune-related genes expression between high-GMS and low-GMS patients. A reduced proportion of tumor-associated fibroblasts and elevated proportion of CD8+ T cells can be observed in low-GMS patients while several immunosuppressive molecules were elevated in the high-GMS patients. Using the sequencing data of the GSE164042 dataset, we also found that myeloid-derived suppressor cell and neutrophil related signature scores were lower in α-glucosidase knockout bladder carcinoma cells when compared to the control group. In addition, angiogenesis, classic carcinogenic pathways, immunosuppressive cells related pathways and immunosuppressive cytokine secretion were mainly enriched in high-GMS patients and cell samples from the control group. Finally, we suspected that the combination treatment of ICI and histone deacetylase inhibitors may achieve better clinical responses in UC patients based on the analysis of drug sensitivity data. In conclusion, our study revealed the predictive value of GMS for ICI efficacy of UC patients, providing a novel perspective for the exploration of new drug targets and potential treatment strategies.

Activation of the DDR Pathway Leads to the Down-Regulation of the TGFß Pathway and a Better Response to ICIs in Patients With Metastatic Urothelial Carcinoma.

Immune checkpoint inhibitors (ICIs) have changed the treatment paradigm of metastatic urothelial carcinoma (mUC), a dominant type of bladder cancer (BC). Previous studies have shown an association between gene mutations in the DNA damage response (DDR) pathway and the immunotherapy response in mUC but have neglected the effect of the activation level of the DDR pathway on the ICI response in mUC. A published immunotherapy cohort with genome, transcriptome and survival data for 348 mUC patients was used. An external cohort (The Cancer Genome Atlas Bladder Cancer) and the GSE78220 cohort were used for validation. The activation level of the DDR pathway was quantified using single-sample gene set enrichment analysis (ssGSEA). Further analysis on the genome, immunogenicity, and the immune microenvironment was conducted using the DDR ssGSEA enrichment score-high (DSSH) group and the DDR ssGSEA enrichment score-low (DSSL) group. In the mUC cohorts, the DSSH group was associated with longer overall survival times (P=0.026; Hazard ratio=0.67; 95%CI: 0.46-0.95). The DSSH group was also associated with higher tumor mutation burden, neoantigen load, immune-activated cell patterns, and immune-related gene expression levels. The GSEA results indicated an immune activation state in DSSH group, which correlated with a down-regulation in the transforming growth factor ß receptor signaling pathway. Our study suggests that the activation level of the DDR pathway may be a novel predictive marker for immunotherapy efficacy in patients with mUC.

Influence of Different Age Cutoff Points on the Prediction of Prognosis of Cancer Patients Receiving ICIs and Potential Mechanistic Exploration.

Age is a potential predictive marker for the prognosis of cancer patients treated with immune checkpoint inhibitors (ICIs), but the appropriate age cutoff point is still controversial. We aimed to explore the influence of different age cutoff points on the prediction of prognosis for patients receiving ICIs and explore the mechanism underlying the appropriate age cutoff point from the aspects of gene mutation and expression, immune cell infiltration and so on. We applied cutoff points of 50, 55, 60, 65, 70, and 75 years old to divide 1660 patients from the Memorial Sloan-Kettering Cancer Center (MSKCC) immunotherapy cohort into older and younger groups and performed survival analysis of the six subgroups. The results showed that older patients had better survival than younger patients in accordance with the cutoff point of 50 years old [median overall survival (OS) (95% CI): 13.0 (10.5-15.5) months vs. 20.0 (16.7-23.3) months; p=0.002; unadjusted hazard ratio (HR) (95% CI): 0.77 (0.65-0.91)], whereas no significant difference was observed with other cutoff points. Further analysis of The Cancer Genome Atlas (TCGA) database and the MSKCC immunotherapy cohort data showed that the tumor mutation burden (TMB), neoantigen load (NAL), DNA damage response and repair (DDR) pathway mutation status, mutation frequencies of most genes (except IDH1, BRAF and ATRX), the expression of most immune-related genes and the degree of infiltration of most immune cells (such as CD8+ T cells and M1 macrophages) were higher in the elderly group (aged ≥50 years).

Alterations in TP53 Are a Potential Biomarker of Bladder Cancer Patients Who Benefit From Immune Checkpoint Inhibition.

In recent years, immune checkpoint inhibitors (ICIs) targeting CTLA-4 or PD1/PDL1 have achieved remarkable success in the treatment of bladder cancer (BLCA), but only a few patients have shown durable clinical benefits. The prognostic role of a mutant form of the tumor suppressor gene TP53 (TP53-MT) in predicting the efficacy of ICIs is highly controversial; therefore, in this study, we obtained data for 210 patients from an immunotherapy cohort, 412 patients from The Cancer Genome Atlas (TCGA)-BLCA cohort and 18 BLCA cell lines from Genomics of Drug Sensitivity in Cancer (GDSC), and we performed integrated bioinformatic analysis to explore the relationships between TP53-MT and clinical benefits derived from ICI treatment and the underlying mechanisms. We conclude that TP53-MT is a potential indicator of a relatively good response to ICIs and associated with prolonged overall survival (OS) (log-rank test, hazard ratio (HR) = 0.65 [95% confidence interval (CI), 0.44-0.99], p = 0.041). Through integrated analysis with several platforms, we found that TP53-MT patients were more likely to benefit from ICIs than wild-type P53 (TP53-WT) patients, which may be the result of 2 major mechanisms. First, the patients with TP53-MT showed stronger tumor antigenicity and tumor antigen presentation, as indicated by a higher tumor mutational load, a higher neoantigen load and increased expression of MHC; second, the antitumor immunity preexisting in tumors was stronger in samples with TP53-MT than in those with TP53-WT, including enrichment of interferon-gamma, positive regulation of TNF secretion pathways and increased expression of some immunostimulatory molecules, such as CXCL9 and CXCL10. This study provided some clues for identifying patients who would potentially benefit from ICIs at the somatic genomic level, developing new indications for targeted second-generation sequencing and promoting the development of precision medicine.

ATM Mutations Benefit Bladder Cancer Patients Treated With Immune Checkpoint Inhibitors by Acting on the Tumor Immune Microenvironment.

Immune checkpoint inhibitors (ICIs) have shown promising results in bladder cancer (BC). However, only some patients respond to ICIs. DNA repair defects (DDR) play an important role in the therapeutic response of bladder cancer. Therefore, we aimed to elucidate the association between ICIs in bladder cancer and ataxia telangiectasia mutated (ATM), a core component of the DNA repair system. From a collected immunotherapy cohort (n = 210) and The Cancer Genome Atlas (TCGA)-Bladder cancer cohort, which were both retrieved from publicly available resources, we performed a series of analyses to evaluate the prognostic value and potential mechanism of ATM in bladder cancer immunotherapy. We found that ATM-mutant (ATM-MT) bladder cancer patients derived greater benefit from ICIs [overall survival (OS), hazard ratio (HR) = 0.28, [95% confidence interval (CI), 0.16 to 0.51], P = 0.007] and showed a higher mutation load (P < 0.05) and immunogenicity (P < 0.05) than ATM-wild-type (ATM-WT) patients. The immune inflammatory response to antigenic stimulation, the regulation of the IFN pathway and the macrophage activation pathway were significantly enriched in the ATM-MT group (NES > 1, P < 0.05), while insulin-like growth factor receptor signaling pathways and vasculogenesis were significantly downregulated (NES < -1, P < 0.05). ATM mutation significantly upregulated the number of DNA damage repair pathway gene mutations (P < 0.05). ATM mutations resulted in increased bladder cancer sensitivity to 29 drugs (P < 0.05), including cisplatin and BMS-536924, an IGF-1R inhibitor. Our results demonstrate the importance of ATM as a prognostic signature in bladder cancer and reveal that ATM may impact the effects of ICIs by acting on the tumor immune microenvironment.

[Synthesis and characterization of folic acid-conjugated chitosan nanoparticles as a tumor-targeted drug carrier].

OBJECTIVE: To synthesize and characterize paclitaxel (PTX)-loaded folate-conjugated chitosan (FA-CTS/PTX) nanoparticles and evaluate its cytotoxicity in vitro. METHODS: CTS/PTX and FA-CTS/PTX nanoparticles were prepared using reductive amidation and ionic gelation of chitosan with tripolyphosphate anions (TPP). The particle size was determined by laser scattering and the morphology observed using transmission electron microscopy, and the PTX content in the nanoparticles was determined using ultraviolet spectrophotometer at 227 nm. The in vitro cytotoxicity of the nanoparticles against HeLa cells was evaluated by MTT assay. Fluorescence microscopy was used to observe the HeLa cells incubated with FA-chitosan nanoparticles in the presence or absence of folic acid in the culture medium. RESULTS: PTX loading did not cause adhesion of the FA-CTS nanoparticles, which presented with uniform spherical morphology with an average diameter of 282.8 nm. The loading and encapsulation efficiencies of FA-CTS/PTX were 9.0% and 75.4%, respectively. The FA-CTS nanoparticles showed a greater extent of intracellular uptake in the absence of folic acid, indicating that the cellular uptake of the nanoparticles occurred through endocytosis mediated by the folate receptors. The PTX-loaded FA-CTS nanoparticles exhibited potent cytotoxicity against HeLa cells, an effect 2- to 3-fold stronger than that of PTX-loaded CTS nanoparticles. CONCLUSION: FA-CTS can be a promising drug carrier with high efficiency in condensing drug, good tumor-targeting ability and low cytotoxicity.

[Correlation of antitumor drug sensitivity between marrow mesenchymal stem cells (MSCs) and hepatocarcinoma cells in rats].

BACKGROUND & OBJECTIVE: As hepatocarcinoma stem cells may originate from oval cells and oval cells are difficult to be separated and purified, MSCs (marrow mesenchymal stem cells), which are the progenitor cells of the hepatocarcinoma stem cells, were selected instead in our study to investigate the correlation of anticancer drug sensitivity between hepatocarcinoma cells and MSCs in rats. METHODS: The primary liver carcinoma modle of rats was induced by diethylnitrosamine. Tumor cells and MSCs from eight hepatocarcinoma rats were separated. The inhibitory effects of 3 anticancer drugs [adriacin (0.04 microg/ml), cisplatin (0.2 microg/ml) and fluorouracil (1 microg/ml)] to hepatocarcinoma cells and MSCs were measured by MTT assay. The weight of the tumor in nude mice which were injected with rat hepatocarcinoma cells was measured after 6 weeks. Then the correlation of the inhibitory ratio of 3 anticancer drugs to hepatocarcinoma cells and MSCs, and to the tumor weight of nude mice was analyzed. RESULTS: No correlation was revealed between the inhibitory ratio of 3 anticancer drugs to hepatocarcinoma cells and the tumor weights of nude mice injectal with drug treated tumor cells. The correlation coefficient was: 0.6307 (adriacin, P>0.05), 0.4358 (fuiorouracil, P>0.05) and 0.7080 (cisplatin, P>0.05). No correlation was observed between the inhibitory ratio of 3 anticancer drugs to hepatocarcinoma cells and to MSCs. The correlation coefficient was: 0.6316 (adriacin, P>0.05), 0.4214 (fluorouracil, P>0.05) and 0.5943 (cisplatin, P>0.05). However, significant reverse correlation was found between the inhibitory ratio of 3 anticancer drugs to MSCs and the tumor weights of nude mice injectal with drug treated tumor cells. The correlation coefficient was: -0.8308 (adriacin, P<0.05), -0.8991 (fluorouracil, P<0.01) and -0.8311 (cisplatin, P<0.05). CONCLUSIONS: Conventional anticancer drug sensitivity experiments could not reflect the chemoresistance of the hepatocarcinoma cells. However the inhibitory ratio of the anticancer drugs to MSCs in the hepatocarcinoma rats can reflect the chemoresistance of hepatocarcinoma cells accordingly.

[The biological behavior of hepatocarcinoma stem cells in rats].

OBJECTIVES: To study the biological behavior of hepatocarcinoma stem cells in rats. METHODS: Primary liver carcinomas were induced in rats using diethylnitrosamine. Tumor cells from 8 rats were separated according to rats oval cell (OVC) markers CD34, c-Kit, Thy-1, AFP, CK7, CK8, CK14, CK18, CK19 and GGT and then they were separately injected into the livers of nude mice. The tumors grown from the different subpopulation of OVC markers in the nude mice livers (10 OVC markers negative or positive cells) were weighted 1 month after the inoculations. The hepatocarcinoma cell subpopulations with higher ability in causing tumor growths were further studied in vitro. The cell cycles and DNA content of those subpopulation cells were investigated using flow cytometry. RESULTS: (1) Subpopulation cells with CK7(-), Thy-1(+) and AFP(+) markers had a higher ability in causing tumors in nude mice; (2) Subpopulation cells, exhibiting characters of TSC, had a low growth rate in vitro. CONCLUSIONS: (1) Different subpopulations of hepatocarcinoma cells had different abilities in causing tumors in rats. Some subpopulation cells, such as CK7(-), Thy-1(+) and AFP(+) cells, have characteristics of tumor stem cells. (2) The hepatocarcinoma stem cells may have a low growth rate in vitro.

[Expression of DNA transcription- and repair-related genes in cisplatin-resistant human ovarian carcinoma cell line COC1/DDP].

OBJECTIVE: To study the molecular mechanism underlying cisplatin resistance in ovarian carcinoma by detecting the expressions of DNA transcription- and repair-related genes in cisplatin-resistant human ovarian carcinoma COC1 cell line. METHODS: The differential expression of DNA transcription- and repair-related genes between the parental COC1 and cisplatin-resistant COC1/DDP cell line was determined using cDNA microarray. RESULTS AND CONCLUSION: Compared with COC1 cells, 143 genes in COC1/DDP cells showed significant differential expression, among which 20 were DNA transcription- and repair-related genes including 13 significantly up-regulated genes and 7 down-regulated ones. Abnormality of DNA transcription and repair might be involved in the development of cisplatin resistance in COC1/DDP cells.

Synthesis of targeted drug delivery system for fluorouracil using sulfadiazine as the carrier.

OBJECTIVE: To synthesize a targeted drug delivery system for 5-fluorouracil (5Fu) using sulfadiazine (SF) as a carrier with reduced side-effects and strong antitumor activity. METHODS: SF-poly (ethylene glycol) (PEG) conjugate was initially synthesized. 5Fu was subjected to reaction with trichloromethyl chloroformate to prepare chloroformyl 5Fu, which was linked to a spacer hydroxyl group of PEG that served as a macromolecular linking arm between SF and 5Fu. The content of 5Fu in the conjugate was determined by ultraviolet spectrophotometry. Spectrum of ultraviolet and infrared along with differential scanning calorimetry were employed to identify the structure of the conjugate of SFPEG-end capped 5Fu. RESULTS: The drug loading content of the conjugate was 3.2 %, and structural analysis confirmed the linkage between 5Fu and SF via PEG. CONCLUSION: Targeted drug delivery system for 5Fu using SF as a carrier has been successfully synthesized by this means.