[Retracted] miR­885­5p upregulation promotes colorectal cancer cell proliferation and migration by targeting suppressor of cytokine signaling.

[This retracts the article DOI: 10.3892/ol.2018.8645.].

Nimotuzumab Plus Gemcitabine for K-Ras Wild-Type Locally Advanced or Metastatic Pancreatic Cancer.

PURPOSE: In a phase IIb trial of nimotuzumab plus gemcitabine, substantial clinical benefits were observed in patients with locally advanced or metastatic pancreatic cancer (PC). Therefore, we conducted a phase III clinical study to verify the efficacy and safety of this combination regimen in patients with K-Ras wild-type tumors (ClinicalTrials.gov identifier: NCT02395016). PATIENTS AND METHODS: Eligible patients were randomly assigned to receive nimotuzumab (400 mg once per week) or placebo followed by gemcitabine (1,000 mg/m2 on days 1, 8, and 15, once every 4 weeks) until disease progression or unacceptable toxicity. The primary end point was overall survival (OS) and the secondary end points were progression-free survival (PFS), response rates, and safety. RESULTS: A total of 480 patients were screened; 92 patients were enrolled and 82 patients with K-Ras wild-type tumors were eligible. In the full analysis set, the median OS was 10.9 versus 8.5 months, while the restricted mean survival time (RMST) was 18.05 versus 11.14 months for the investigational versus control arm (ratio of control v investigation = 0.62 [0.40-0.97]; P = .036). Median PFS was 4.2 versus 3.6 months in the investigational versus control arm (log-rank P = .04; hazard ratio, 0.60 [0.37-0.99]) and the restricted mean PFS time was 8.08 versus 4.76 months (RMST ratio, 0.58 [0.38-0.90]; P = .036). Both OS and PFS were longer in the nimotuzumab group than in the placebo group. The objective response rates and disease control rates were 7% versus 10% and 68% versus 63% for the investigational and control groups, respectively. The incidence of adverse events were comparable between the two groups. CONCLUSION: In patients with locally advanced or metastatic K-Ras wild-type PC, nimotuzumab plus gemcitabine significantly improved OS and PFS with a good safety profile.

Research progress of integrated traditional Chinese and Western medicine in the treatment of advanced gastric cancer.

Gastric cancer (GC) is a malignant tumor originating from the gastric epithelium, and its incidence and mortality rates rank third among all malignant tumors worldwide. It is also one of the most common cancers in China and is treated predominantly by Western medicine in clinical practice. However, with the advancements in medical technology and informatics, the values of traditional Chinese medicine (TCM) in preventing and treating GC and improving prognosis have increasingly been recognized. According to TCM, clinical manifestations of GC can be divided into Yege (dysphagia), regurgitation, stomach pain, and Zhengxia (abdominal mass). Due to the unbalanced distribution of health care resources in China, most GC patients already have progressive or advanced-stage disease at the first diagnosis. As a result, most GC patients have poor physical function, and surgery or chemotherapy alone will aggravate the impairment to the immune function and seriously affect the quality of life. In contrast, TCM therapies have shown promising efficacy in the management of these patients. Here we review the role of the integrated TCM and Western medicine in treating advanced GC.

Anlotinib Monotherapy for Refractory Metastatic Colorectal Cancer: A Double-Blinded, Placebo-Controlled, Randomized Phase III Trial (ALTER0703).

BACKGROUND: Treatment options for refractory metastatic colorectal cancer (mCRC) were limited. Anlotinib is a novel multitarget tyrosine kinase inhibitor. ALTER0703 study was conducted to assess efficacy and safety of anlotinib for patients with refractory mCRC. MATERIALS AND METHODS: This was a multicenter, double-blinded, placebo-controlled, randomized phase III trial involving 33 hospitals in China. Patients had taken at least two lines of therapies were 2:1 randomized to receive oral anlotinib (12 mg/day; days 1-14; 21 days per cycle) or placebo, plus best supportive care. Randomization was stratified by previous VEGF-targeting treatments and time from diagnosis to metastases. The primary endpoint was overall survival (OS). The secondary endpoints were progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), quality of life (QoL), and safety. RESULTS: A total of 419 patients (anlotinib: 282; placebo: 137) were treated from December 2014 to August 2016. The median PFS was improved in anlotinib group (4.1 months; 95% confidence interval [CI], 3.4-4.5) over placebo group (1.5 months; 95% CI, 1.4-1.5), with a hazard ratio (HR) of 0.34 (95% CI, 0.27-0.43; p < .0001). However, median OS was similar between two groups (8.6 months; 95% CI, 7.8-9.7 vs. 7.2 months; 95% CI, 6.2-8.8; HR, 1.02; p = .870). Improvements of ORR and DCR were observed in anlotinib over placebo. The most common grade ≥ 3 anlotinib related adverse events were hypertension (20.92%), increased γ-GT (7.09%), and hand-foot skin reaction (6.38%). CONCLUSION: Anlotinib was tolerated in Chinese patients with refractory mCRC. Although OS did not reach significant difference, anlotinib still provided clinical benefits by substantially prolonged PFS in these patients. IMPLICATIONS FOR PRACTICE: In this randomized clinical trial that included 419 patients with refractory metastatic colorectal cancer, substantial prolonged in progression-free survival was noted in patients who received anlotinib compared with those given placebo. Improvements on objective response rate and disease control rate was also observed in anlotinib group. However, overall survival was similar between the two groups. In a word, in third-line or above treatment of Chinese patients with refractory metastatic colorectal cancer, anlotinib provided clinical benefit by significantly prolonged progression-free survival.

Emerging roles of circular RNAs in non­small cell lung cancer (Review).

Circular RNAs (circRNAs) are a class of novel endogenous transcripts with limited protein­coding abilities. CircRNAs have been demonstrated to function as critical regulators of tumor development and distant metastasis through binding to microRNAs (miRNAs) and interacting with RNA­binding proteins, thereby regulating transcription and translation. Emerging evidence has illustrated that certain circRNAs can serve as biomarkers for diagnosis and prognosis of cancer, and/or serve as potential therapeutic targets. Expression of functional circRNAs is commonly dysregulated in cancer and this is correlated with advanced Tumor­Node­Metastasis stage, lymph node status, distant metastasis, poor differentiation and shorter overall survival of cancer patients. Recently, an increasing number of studies have shown that circRNAs are closely associated with NSCLC. Functional experiments have revealed that circRNAs are intricately associated with the pathological progression of NSCLC. The present review provides an overview of the regulatory effect of circRNAs in the development and progression of NSCLC, taking into consideration various physiological and pathological processes, such as proliferation, apoptosis, invasion and migration, and their potential value as biomarkers and therapeutic targets.

CircHIPK3 promotes colorectal cancer cells proliferation and metastasis via modulating of miR-1207-5p/FMNL2 signal.

Increasing evidences demonstrate that circular RNAs (circRNAs) are extensively implicated in various cancers including colorectal cancer (CRC). In the present study, we found that circRNA HIPK3 (circPIK3) was upregulated in CRC. We identified that circHIPK3 was closely related with unfavorable clinicopathological features in patients with CRC. Functional transwell assay and proliferation assay indicated that circHIPK3 served as an oncogene and promoted CRC cells migration, invasion and proliferation. Meanwhile, we found that formin like 2 (FMNL2) was a key downstream molecule in circHIPK3-induced metastasis and proliferation in CRC cells. We further verified that circHIPK3 was mainly located at cytoplasm through an immunofluorescence assay. An online bioinformatics screening and a GEO datasets analysis showed that microRNA 1207-5p (miR-1207-5p) was downregulated in CRC. Also, we found that miR-1207-5p shared a similar miR-1207-5p response elements (MREs-1207-5p). Meanwhile, we showed that miR-1207-5p suppressed CRC cells migration, invasion and proliferation via directly targeting of FMNL2. Even further, via a constructed luciferase assay, we indicated that circHIPK3 was another target of miR-1207-5p. Functionally, we proved that circHIPK3 enhanced FMNL2 mediated promotion of migration, invasion and proliferation by sponging of miR-1207-5p in CRC cells. In summary, the outcomes of this study illustrated that circHIPK3 promoted CRC cells migration, invasion and proliferation modulating of FMNL2 by sponging of miR-1207-5p. Our findings indicated that circHIPK3/miR-1207-5p/FMNL2 axis might be a new strategy in molecular treatment of CRC.

Circular RNA hsa_circ_0004277 contributes to malignant phenotype of colorectal cancer by sponging miR-512-5p to upregulate the expression of PTMA.

In recent years, extensive reports have been published concerning the molecular mechanism underlying the occurrence and progression of colorectal cancer. Circular RNAs (circRNAs) have been identified as important modulators in the biological processes of colorectal cancer. Microarray analysis unveiled that differential circ-0004277 expression was identified in tissue samples of colorectal cancer. High circ-0004277 expression was then verified in tissue samples and cell lines of colorectal cancer via qRT-PCR. Kaplan-Meier analysis was used for identifying the association between circ-0004277 expression and the overall survival rate of colorectal cancer patients. A relationship existed between higher circ-0004277 expression and decreased overall survival rate of colorectal cancer patients. From a functional perspective, circ-0004277 knockdown accelerated cell apoptosis and restrained cell proliferation of colorectal cancer. From mechanistic perspective, circ-0004277 upregulated PTMA by sponging miR-512-5p. Rescue assay was used for verifying the roles of the circ-0004277-miR-512-5p-PTMA axis. Both miR-512-5p and PTMA participated in circ-0004277-mediated colorectal cancer cell proliferation based on experiments. In summary, our study showed that circ-0004277 promoted the proliferation of colorectal cancer cells as a miR-512-5p sponge to upregulate the PTMA expression.

Identification of seven-gene signature for prediction of lung squamous cell carcinoma.

Background and aim: Lung squamous cell carcinoma (LUSC), is a pathological subtype of lung cancer, accounting for 30% of the lung cancers. A reliable model was constructed, based on the whole gene expression profiles, to predict the prognosis of patients with LUSC. Methods: The RNA-Seq data of LUSC was downloaded from the TCGA database, and differentially expressed genes (p<0.05, |log2fold change| >1) were screened out. By univariate and multivariate Cox regression analysis, we identified seven prognosis-related genes. Then, we established a risk score staging system to predict the prognosis of patients with LUSC. Compared with other clinical parameters, the risk score was an independent prognostic factor and had a better performance in predicting prognosis. Finally, GSEA analysis was carried out to determine the enrichment pathway significantly. The risk score models were established by Cox proportional hazard regression analysis; the ROC curve was applied to test the performance of risk score model. All the statistical analysis was accomplished by R packages. Results: In this study, a model was constructed to predict prognosis, which contains seven genes: CSRNP1, CLEC18B, MIR27A, AC130456.4, DEFA6, ARL14EPL, and ZFP42. Based on the model, the risk score of each patient was calculated with LUSC (hazard ratio [HR]=2.673, 95% CI=1.871-3.525). It was found that the risk score can distinguish high-risk and low-risk groups in prognosis of LUSC patients, independently. Furthermore, the model was validated by ROC curves in the testing dataset and the whole dataset. Lastly, by gene set enrichment analysis (GSEA), we showed the main enrichment pathways were DNA damage stimulus, DNA repair, and DNA replication. It was suggested that the risk score may provide a new and reliable method for prognosis prediction. Conclusion: The results of this study suggested that the risk score based on seven-genes could indicate a promising and independent prognostic biomarker for LUSC patients.

Circular RNA PVT1 promotes metastasis via miR-145 sponging in CRC.

Circular RNAs (circRNAs) are a class of covalently closed non-coding RNAs and are widely involved in various cancers including colorectal cancer (CRC). Circular RNA PVT1 (circPVT1) was reported in several malignancies but the role it plays in CRC remains unclear. In our current research, we focused on the expression and function of circPVT1) works in CRC. We found that circPVT1 was upregulated in CRC. Also, we illustrated that the upregulated circPVT1 was closely correlated with poor prognosis and bad clinicopathological features of patients with CRC. Through a loss of function experiment, we showed that a downregulation of circPVT1 suppressed CRC cells metastasis. Through online prediction, we found that circPVT1 had a microRNA response element (MRE) for miR-145. Additionally, we demonstrated that miR-145 was downregulated in CRC. Even further, we showed that miR-145 was involved in circPVT1 mediated facilitation of CRC metastasis. In a further mechanical study, we demonstrated that circPVT1 could target miR-145. Lastly, we revealed that the metastasis-promoting role of circPVT1 in CRC was partially achieved via miR-145 sponging. In brief, the findings of the present study illustrated that circPVT1, working as an oncogene, promotes metastasis via miR-145 sponging in CRC. CircPVT1/miR-145 axial might be a novel point in targeting treatment of CRC.

Prognostic and clinicopathological significance of long noncoding RNA CTD-2510F5.4 in gastric cancer.

BACKGROUND: Compelling studies have demonstrated the correlation between aberrant expressed lncRNAs and human cancers, and revealed promise of these lncRNAs as biomarkers in predicting patients' survival and outcome. METHODS: We downloaded the RNA-seq data from the Cancer Genome Atlas, and screened out DEGs and DELs between gastric cancer tissues and normal gastric tissues. By bioinformatics analysis, we identified CTD-2510F5.4 was a malignant phenotype associated lncRNA. The expression levels of CTD-2510F5.4 in tissues were detected by ISH, and the relationships between CTD-2510F5.4 expression and clinicopathological characteristics were analyzed by statistical analysis. RESULTS: By bioinformatics analysis and functional analysis, we identified CTD-2510F5.4 was a malignant phenotype associated lncRNA of gastric cancer that potentially regulated cell cycle and apoptosis. CTD-2510F5.4 expression was significantly higher in gastric cancers, and was correlated with pathological grade, vascular or nerve invasion, AJCC TNM stage and OS. Moreover, gastric cancer patients with high CTD-2510F5.4 expression showed significantly shorter MST. High CTD-2510F5.4 expression was a independent risk factor for gastric cancers at pathological grade < III and without vascular or nerve invasion. CONCLUSIONS: We identified CTD-2510F5.4 was a malignant phenotype associated lncRNA potentially involved in the pathogenesis of gastric cancer. Our data also supported the clinical potential of CTD-2510F5.4 being a diagnostic and prognostic biomarker for gastric cancer.

A novel long noncoding RNA, LINC00483 promotes proliferation and metastasis via modulating of FMNL2 in CRC.

Long non-coding RNAs (lncRNAs) are extensively involved in multiple malignancies including colorectal cancer (CRC). In the present study, we found a novel lncRNA, long intergenic non-protein coding RNA 483 (LINC00483), which was upregulated in CRC. We also illustrated that upregulated LINC00483 was correlated with poor clinicopathological features of patients with CRC. Functionally, we displayed that a knockdown of LINC00483 suppressed LOVO and HT29 cells proliferation and metastatic ability. We further illustrated that miR-204-3p was involved in LINC00483 induced proliferation and metastasis. An overexpression of miR-204-3p could attenuate the facilitative effect which LINC00483 presented. Through a luciferase assay, we showed the direct binding effect between LINC00483 and miR-204-3p. Even further, we revealed that LINC00483 and formin like 2 (FMNL2) shared a similar miR-204-3p response elements (MREs-204-3p). FMNL2 was a direct target of miR-204-3p. FMNL2 was a downstream gene of LINC00483 and participated in LINC00483 mediated proliferation and metastasis. Lastly, we proved that LINC00483 promoted proliferation and metastasis via modulating of FMNL2 in LOVO and HT29 cells. In summary, the outcomes of this study illustrated that LINC00483 promoted CRC cells proliferation and metastasis via modulating of FMNL2 by acting as a ceRNA of miR-204-3p. LINC00483/miR-204-3p/FMNL2 axial might be a novel target in molecular treatment of CRC.

Paclitaxel reversed trastuzumab resistance via regulating JUN in human gastric cancer cells identified by FAN analysis.

AIM: In this study, we aim to use bioinformatics approach to identify paclitaxel-targeted modulators potentially involved in the process of reversing the trastuzumab resistance. Materials & methods: We extracted data from GSE77346 to identify potential trastuzumab resistance-related genes, used bioinformatics analysis and functional/activity network approach to find genes involved in trastuzumab resistance reversal. RESULTS: We identified hub differentially expressed genes related to trastuzumab resistance, trastuzumab targeting and paclitaxel targeting, respectively. We then found C-Jun may be critical in trastuzumab resistance reversal.  This process may involve transcriptional activation of DUSP1 by JUN, which lead to regulation of DUSP1-related signaling pathways. CONCLUSION: The present study revealed paclitaxel may reverse the trastuzumab resistance by JUN, which possibly in turn regulated DUSP1 and DUSP1-related signaling pathways.

Long noncoding RNA MALAT1 regulates HDAC4-mediated proliferation and apoptosis via decoying of miR-140-5p in osteosarcoma cells.

Noncoding RNAs regulate the initiation and progression of osteosarcoma (OS). The role of long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) playing in OS and whether the function it working out was achieved through HDAC4 pathway remain uncovered. In this study, we illustrated that MALAT1 was upregulated and was correlated with poor prognosis in OS patients. Meanwhile, we demonstrated that a depression of MALAT1 suppressed proliferation and promoted apoptosis in OS cell line HOS and 143B. Further, we verified that MALAT1 exerting its function via upregulating of histone deacetylase 4 (HDAC4). Through an online prediction, a series of luciferase assays and RNA pull-down assays, we demonstrated that both MALAT1 and HDAC4 were the targets of microRNA-140-5p (miR-140-5p) via sharing a similar microRNA responding elements. Even further, we revealed that MALAT1 served as a ceRNA of HDAC4 via decoying of miR-140-5p. Finally, we proved that MALAT1 promoted OS tumor growth in an in vivo animal study. In summary, the outcomes of this study demonstrated the complex ceRNA network among MALAT, miR-140-5p, and HDAC4-mediated proliferation and apoptosis in OS. This study might provide a new axial in molecular treatment of OS.

miR-885-5p upregulation promotes colorectal cancer cell proliferation and migration by targeting suppressor of cytokine signaling.

The aim of the present study was to investigate the role of microRNA (miR)-885-5p in colorectal cancer cell proliferation and migration, and to determine the possible underlying molecular mechanisms. The expression of miR-885-5p in colorectal cancer tissue and cells was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The expression levels of three suppressor of cytokine signaling (SOCS) factors were detected by RT-qPCR and western blotting. The effects of miR-885-5p on tumor cell proliferation and migration were studied using MTT and Transwell assays, respectively. Additionally, the expression levels of epithelial-mesenchymal transition (EMT)-related proteins (N-cadherin, E-cadherin, vimentin and Snail) were detected by RT-qPCR and western blot analysis. Furthermore, the target of miR-885-5p was predicted and confirmed using a luciferase reporter assay. miR-885-5p was demonstrated to be upregulated and SOCS was downregulated in colorectal cancer tissue, and cells. miR-885-5p suppression significantly inhibited tumor cell proliferation and migration, promoted E-cadherin expression, and inhibited the expression levels of N-cadherin, vimentin and Snail. Further studies showed that SOCS5, SOCS6 and SOCS7 were direct targets of miR-885-5p. The results suggest that miR-885-5p suppression inhibited cell proliferation and migration, and the EMT process by targeting SOCS5, SOCS6 and SOCS7 genes in colorectal cancer. miR-885-5p and SOCS may be used for the diagnosis and treatment of colorectal cancer.

Andrographolide enhanced 5-fluorouracil-induced antitumor effect in colorectal cancer via inhibition of c-MET pathway.

Colorectal cancer (CRC) is the third most common malignant neoplasm worldwide. 5-Fluorouracil (5-Fu) is the most important chemotherapeutic drug used for the treatment of CRC. However, resistance to 5-Fu therapies is a growing concern in CRC clinical practice recently. Andrographolide (Andro) is a main bioactive constituent of the herb Andrographis paniculata, which has various biological effects including anti-inflammation and antitumor activities. In the present study, we investigated the effects of combined Andro with 5-Fu against CRC HCT-116 cells. In vitro studies showed that Andro synergistically enhanced the anti-proliferation effect of 5-Fu on HCT-116 cells due to increased apoptotic cells. Meanwhile, results of the enzyme linked immunosorbent assay indicated that the level of phosphorylated cellular-mesenchymal to epithelial transition factor (p-MET) was decreased by the combination treatment. Further study suggested that Andro promoted the antitumor effect of 5-Fu by down-regulating the level of p-MET. In conclusion, these results confirmed the synergistic antitumor activity of Andro on CRC and provide evidence for possible clinical application of Andro for enhancing the antitumor effect of 5-Fu in CRC treatment.

GSTT1 null genotype contributes to increased risk of gastric cancer in Chinese population: evidence from a meta-analysis.

Previous studies suggested glutathione S-transferase T1 (GSTT1) null genotype might be a candidate genetic polymorphism with a role in the susceptibility to gastric cancer, but studies form Chinese population reported controversial findings. Thus, a meta-analysis was performed to clarify the effect of GSTT1 null genotype on gastric cancer risk in Chinese population. Eligible studies were searched in Medline, Embase, and China National Knowledge Infrastructure databases. Between-study heterogeneity was assessed using the I (2) statistic. Odds ratios (OR) with the corresponding 95 % confidence intervals (95 % CI) were pooled to assess the association. Twenty case-control studies involving a total of 3,204 gastric cancer cases and 5,462 controls were finally included in the meta-analysis. Meta-analysis of all 20 studies showed that GSTT1 null genotype was associated with an elevated risk of gastric cancer in Chinese population (OR=1.26, 95 % CI 1.09-1.46, P OR=0.002). The cumulative meta-analysis showed a trend of a more obvious association between GSTT1 null genotype and risk of gastric cancer in Chinese population as information accumulated gradually. Sensitivity analysis by omitting individual study, in turns, did not materially alter the pooled ORs. This meta-analysis provides a strong evidence for the significant association between GSTT1 null genotype and gastric cancer risk in Chinese population, and GSTT1 null genotype contributes to increased risk of gastric cancer.

Schedule-dependent synergistic interaction between gemcitabine and oxaliplatin in human gallbladder adenocarcinoma cell lines.

To define the most effective combination schedule of gemcitabine and oxaliplatin (L-OHP), we investigated the in-vitro interaction between these drugs in a panel of four human gallbladder adenocarcinoma cell lines (HAG-1, GB-d1, NOZ, and G-415). Cytotoxic activity was determined by the WST-1 assay. Different schedules of the two drugs were compared and evaluated for synergism, additivity, or antagonism with a quantitative method based on the median-effect principle of Chou and Talalay. Cell cycle perturbation and apoptosis were evaluated by flow cytometry. Simultaneous and sequential treatments of gemcitabine followed by L-OHP exhibited synergistic effects in all four cell lines, whereas the reverse sequence largely showed an antagonism. Gemcitabine exclusively arrested cells at the G0/G1 phase, and L-OHP at the G2/M phase, as measured by flow cytometric analyses. Apoptosis was most prominent when cells were treated simultaneously or in a sequence gemcitabine followed by L-OHP, producing apoptosis in treated cells (27-30%). In contrast, the reverse sequence yielded only 6-7% induction of apoptosis, the rate being not significantly different from those induced by each drug singly. Moreover, this sequence dependence was further confirmed by the experiment, which compared the number of HAG-1 cells 7 days after these combination schedules. These findings suggest that the interaction of gemcitabine and L-OHP is highly schedule dependent, with the most efficacious interaction observed in either simultaneous combination or in a sequence combination of gemcitabine followed by L-OHP.

Metastatic basaloid-squamous cell carcinoma of the esophagus treated by 5-fluorouracil and cisplatin.

Basaloid squamous cell carcinoma (BSC) of the esophagus is a rare malignant disease. We report here a patient with recurrent esophageal BSC, who was successfully treated by systemic chemotherapy containing 5-fluorouracil (5-FU) and cisplatin (CDDP). A 57-year-old woman was diagnosed as having squamous cell carcinoma of the esophagus upon endoscopic examination. Curative esophagectomy with lymph node dissection was performed under the thoracoscope. The pathological diagnosis of the surgical specimen was BSC. Five months after operation, the patient was diagnosed as having a recurrence of the BSC with metastases to the liver and spleen, and a right paraclavicular lymph node. She was given systemic chemotherapy consisting of continuous infusion of 800 mg/d of 5-FU and 3 h infusion of 20 mg/d of CDDP for 5 consecutive days every 4 wk. The metastatic lesions in the spleen and right paraclavicular lymph node disappeared, and the liver metastasis was apparently reduced in size after 2 courses of chemotherapy. The tumor regression was seen over 6 courses, with progression afterwards. Although subsequent treatment with CPT-11 and CDDP was not effective, docetaxel and vinorelbine temporarily controlled the tumor growth for 2 mo. 5-FU and CDDP combination may be useful for the patients with advanced BSC.

In-vitro differential metabolism and activity of 5-fluorouracil between short-term, high-dose and long-term, low-dose treatments in human squamous carcinoma cells.

Although continuous infusion of 5-fluorouracil (5-FU) has been clinically demonstrated to be superior to bolus administration, the mechanistic difference between the treatments still remains unclear. Here, we investigated in vitro whether there were any differences in the metabolism and activity of 5-FU between these schedules. To simulate bolus and infusional treatments of 5-FU, HST-1 human squamous carcinoma cells were treated with short-term, high-doses and long-term, low-doses so that the area under the curve (AUC) of 5-FU became equivalent between both schedules, and compared the cytotoxicity, fluorinated RNA (F-RNA) levels, 5-fluorodeoxyuridine monophosphate (FdUMP) content and thymidylate synthase (TS) activity. F-RNA and FdUMP were measured by capillary gas chromatography-mass spectrometry and competitive ligand-binding assay, respectively. The [H]FdUMP binding site in TS was determined as an index of the amount of TS using the radio-binding assay. Long-term, low-dose treatment of 5-FU was found to be 1.3-1.7 times more cytotoxic than the short-term, high-dose treatment. F-RNA content increased as the AUC of 5-FU was increased and was 2-4 times significantly higher in the cells treated with the long-term, low-dose than those with the short-term, high-dose schedule, indicating that the levels of F-RNA are AUC and schedule dependent. In contrast, there were no significant differences in FdUMP levels, TS activity and TS inhibition rate between the schedules. These data suggest that the superior activity of 5-FU administered long-term, low-dose over short-term, high-dose could be explained by more 5-FU incorporated into RNA during a long-term, low-dose exposure, thus providing a strategic rationale for the clinical advantage of continuous infusion over bolus administration.

In-vitro schedule-dependent interaction between oxaliplatin and 5-fluorouracil in human gastric cancer cell lines.

In order to define the most effective combination schedule of oxaliplatin (L-OHP) and 5-fluorouracil (5-FU), we investigated the in vitro interaction between these drugs in a panel of four human gastric adenocarcinoma cell lines (MKN-1, NUGC-3, NUGC-5 and AZ-521). Cytotoxic activity was determined by the WST-1 assay. Different schedules of the two drugs were compared and evaluated for synergism, additivity or antagonism with a quantitative method based on the median-effect principle of Chou and Talalay. Cell cycle perturbation and apoptosis were evaluated by flow cytometry. Simultaneous and sequential treatments of L-OHP followed by 5-FU exhibited synergistic effects in all four cell lines, whereas the reverse sequence yielded a clear antagonism. 5-FU exclusively arrested cells at the G0/G1 phase, and L-OHP at the G0/G1 and G2/M phases. Apoptosis was most prominent when cells were treated simultaneously or in a sequence of L-OHP followed by 5-FU, producing apoptosis in the majority of treated cells (55.5-61.5%). In contrast, the reverse sequence yielded only 20% induction of apoptosis, the rate being not significantly different from those induced by each drug singly. Moreover, this sequence dependence was further confirmed by the experiment which compared the total number of NUGC-3 cells 7 days after these combination schedules. These findings suggest that the interaction of 5-FU and L-OHP could be highly schedule dependent, with the most efficacious interaction observed in simultaneous combination and that 5-FU followed by L-OHP would not be recommended in clinical trials for patients with advanced gastric cancer.