Efficacy and safety of trifluridine/tipiracil plus bevacizumab versus trifluridine/tipiracil monotherapy for refractory metastatic colorectal cancer: a retrospective cohort study.

Background: Several studies demonstrated trifluridine/tipiracil (TAS-102) plus bevacizumab (BEV) had better efficacy than the monotherapy of TAS-102 in refractory metastatic colorectal cancer (mCRC). However, it remains unclear whether Chinese population can benefit from this combination or not. Hence, we conducted this retrospective cohort study to compare the efficacy and safety between TAS-102 plus BEV with TAS-102 monotherapy in refractory mCRC. Methods: This retrospective cohort study enrolled patients (any age) with refractory mCRC from Hunan Cancer Hospital. The main inclusion criteria were histopathologically and/or radiographically confirmed refractory mCRC, World Health Organization (WHO) performance status of 0 to 2, adequate organ function, and initial treatment of TAS-102 with or without BEV between November 2020 and October 2022. Previous therapy with fruquintinib or regorafenib was allowed but not mandatory. Baseline demographic and clinical characteristics were collected appropriately. Every 2 or 3 treatment cycles, the patients were assessed by computed tomography (CT) scans and clinical assessments until disease progression or loss to follow-up. The National Cancer Institute Common Terminology Criteria for Adverse Events 5.0 (NCI-CTCAE 5.0) were presented as n (%). The primary endpoint was investigator-evaluated overall survival (OS). As this is a retrospective cohort study, sample size calculation was not performed. Eligible patients would be enrolled as many as possible. Results: A total of 90 patients were enrolled, including 58 patients who received TAS-102 plus BEV and another 32 patients who received TAS-102 monotherapy. The known baseline characteristics were comparable (P<0.05). With a median follow-up of 4.60 months (range, 0.20-22.80), the median OS (mOS) time in the TAS-102 plus BEV group was longer than that in the TAS-102 monotherapy group (10.83 vs. 7.43 months), but the difference was not significant (P=0.79). The median progression-free survival (mPFS) time was comparable between the two groups (4.67 vs. 4.30 months, P=0.96). Multivariate Cox regression analysis demonstrated that undergoing therapy after TAS-102 either with or without BEV was an independent risk factor for OS [hazard ratio (HR) =0.25; 95% confidence interval (CI): 0.09-0.71, P<0.01], and previous treatment with cetuximab was an independent protective factor for PFS (HR =0.17; 95% CI: 0.03-0.91, P=0.04). Of the 70 patients who were evaluated, those receiving TAS-102 plus BEV showed trend of a higher objective response rate (ORR) and disease control rate (DCR) than those who received TAS-102 monotherapy (P=0.16 and P=0.29, respectively). Adverse events (AEs) were similar between the two groups, except that the incidence of platelet count decrease (grade ≥3) was significantly higher in the TAS-102 plus BEV group. Conclusions: There was a trend in favor of the combination of BEV plus TAS-102 regarding OS and DCR, without reaching statistical significance, and it means that there was no clear advantage of one over the other in terms of efficacy. Further prospective studies are still necessary to draw a definite conclusion.

A cross-sectional study evaluating health-related quality of life of Chinese pediatric patients with hematological malignancies using EQ-5D-Y.

Background: The study aimed to assess health-related quality of life (HRQoL) and to estimate the health utility of pediatric patients with hematological malignancies (HMs) in China. Method: A cross-sectional study recruited a series of pediatric inpatients diagnosed with HM from November 2018 to May 2019 in the Shanghai Children's Medical Center. Subjects were interviewed to collect sociodemographic information about themselves and their guardians. The EQ-5D-Y was completed by each patient to rate their own HRQoL, which later derived the health utility. The health status was also assessed by clinicians following the Eastern Cooperative Oncology Group (ECOG) system. Upon the descriptive analysis and univariate analysis, multivariate generalized linear models were built to explore the associations of risk factors with HRQoL measures of utility, Visual Analog Scale (VAS) score, and the five EQ-5D-Y domains. Results: The 96 subjects had a mean age of 10.5 years and included 62 (64.4%) boys. There were 46 (47.9%) and 25 (26.0%) children diagnosed with acute lymphoblastic leukemia and non-Hodgkin's lymphoma, respectively. The means (SD) of utility and EQ-VAS scores were 0.88 (0.10) and 85.8 (15.1), respectively. Twenty-six (27.1%) patients were graded poor health by the ECOG standard (score 2/3). Both univariate and multivariate analyses found strong correlations between ECOG and HRQoL. After adjusting for covariates, poor ECOG score was significantly associated with an impaired utility and VAS of -0.103 and -8.65, respectively. With regard to individual HRQoL domains, worse ECOG was more likely to report health problems with an increased risk of 2.94 to 12.50; residence, income, guardians' education, and disease duration were also found to be significantly related to either the utility or certain health domains. Conclusion: The HRQoL of Chinese pediatric patients with HM is considered relatively poor and of great concern to healthcare. With the strong correlations between EQ-5D-Y-related HRQoL measures and the traditional clinical index ECOG, the EQ-5D-Y is able to provide valuable evidence for clinical decision-making at the individual level. At the same time, its health utility can inform resource allocation at a macro level.

Cost-effectiveness analysis of glecaprevir/pibrentasvir regimen for treating Chinese patients with chronic hepatitis C genotype 1 and genotype 2 infection.

BACKGROUND: Hepatitis C virus (HCV) infection is an important health threat in China to which direct acting antivirals (DAAs) are very effective. In 2019, another novel DAA glecaprevir/pibrentasvir (GLE/PIB) was officially approved. Knowledge of its cost-effectiveness would be informative for clinical decision-making but has not been evaluated. This study aims to evaluate the cost-effectiveness of GLE/PIB to inform policy-making on drug reimbursement and HCV eradication. METHODS: Markov models were developed from the payers' perspective and simulated the lifetime experience of adult patients chronically infected with HCV genotype 1 or genotype 2. Two regimens, GLE/PIB and pegylated interferon (pegIFN) plus ribavirin (RBV), were compared in cost and quality adjusted life years (QALY) with both outcomes being discounted to 2020 values. The incremental cost-effectiveness ratio (ICER) was computed to reflect the incremental benefit of GLE/PIB versus pegIFN + RBV. The robustness of the model outcomes was examined using deterministic and probabilistic sensitivity analysis (PSA) to identify influential parameters and to assess the probability of GLE/PIB being cost-effective. The GDP per capita in China in 2019 ($10,275) was used as the threshold for cost-effectiveness. RESULTS: For the entire target population, GLE/PIB was the dominant regimen attaining a cost-saving of $255 and 1.17 more QALYs relative to pegIFN + RBV. The finding was more pronounced for HCV genotype 1 infection by saving $1,656 and creating 1.37 more QALYs. At the $10,275 threshold, the probability of GLE/PIB being cost-effective was 99.32% overall and 99.85% for HCV genotype 1 infection. The age of starting DAA treatment, price of pegIFN + RBV, cost of cirrhosis treatment and duration of the GLE/PIB regimen were the five most influential factors. For the patients with HCV genotype 2 infection, the ICER of GLE/PIB was $12,914/QALY with 95% confidence interval of $4,047/QALY to $37,640/QALY. The GLE/PIB regimen statistically cannot be ruled out as a cost-effective option for HCV genotype 2 infection. CONCLUSIONS: GLE/PIB is a cost-effective strategy to treat chronic HCV genotype 1 and HCV genotype 2 infection in China. This regimen should be initiated at a younger age to maximize its value. To achieve national eradication, it may be timely to consider replacing pegIFN + RBV with DAAs, such as GLE/PIB, as the first-line treatment.

Attitudes and Concerns of Diabetic Patients towards Bariatric Surgery as Treatment of Diabetes.

INTRODUCTION: Bariatric surgery is increasingly recognised as an effective treatment for type 2 diabetes that significantly improves glycaemic control, even achieving remission. This study examined perceptions and concerns of diabetic patients towards bariatric surgery as a treatment option for diabetes. MATERIALS AND METHODS: A total of 150 patients were recruited from a specialised diabetic outpatient clinic and completed a questionnaire (items were rated on a Likert scale from slightly important [lowest score of 1] to extremely important [maximum score of 5]). Logistic regression was performed to identify factors influencing decision for surgery. RESULTS: The 74 males and 76 females had mean age of 50 (range 20 to 78) and body mass index (BMI) of 29.6 kg/m2 (range 18.1 to 51); 61% considered surgery favourably. Predictive factors for interest in surgery: higher educational levels (OR = 2.3; 95% CI, 1.2 to 4.4), duration of diabetes (OR = 0.4; 95% CI, 0.2 to 1.0) and use of insulin (OR = 2.1; 95% CI, 1.1 to 4.1). Reasons for surgery: desire for remission (Likert scale 4.7 ± 0.7), to prevent complications (Likert scale 4.5 ± 0.9) and to reduce medications (Likert scale 4.3 ± 1.1). For those not keen on surgery, main reasons were fear of surgery (Likert scale 4 ± 1.5) and satisfaction with current therapy (Likert scale 3.7 ± 1.6). CONCLUSION: Many diabetic patients would consider surgery as an option to improve their metabolic disorder (greater interest in patients with higher educational levels, currently using insulin and with shorter duration of diabetes). Surgical complications, length of recovery and duration of benefits were the main concerns.

Determining the cost-effectiveness of endoscopic surveillance for gastric cancer in patients with precancerous lesions.

AIM: To identify the optimal strategy for gastric cancer (GC) prevention by evaluating the cost-effectiveness of esophagogastroduodenoscopy (EGD)-based preventive strategies. METHODS: We conducted a model-based cost-effectiveness analysis. Adopting a healthcare payer's perspective, Markov models simulated the clinical experience of the target population (Singaporean Chinese 50-69 years old) undergoing endoscopic screening, endoscopic surveillance and usual care of do-nothing. The screening strategy examined the cohort every alternate year whereas the surveillance strategy provided annual EGD only to people with precancerous lesions. For each strategy, discounted lifetime costs ($) and quality adjusted life years (QALY) were estimated and compared to generate incremental cost-effectiveness ratio (ICER). Deterministic and probabilistic sensitivity analysis was conducted to identify influential parameters and quantify the impact of model uncertainties. RESULTS: Annual EGD surveillance with an ICER of $34 200/QALY was deemed cost-effective for GC prevention within the Singapore healthcare system. To inform implementation, the models identified six influential factors and their respective thresholds, namely discount rate (<4.20%), age of starting surveillance (>51.6 years), proportion of program cost in delivering endoscopy (<65%), cost of follow-up EGD (<$484), utility of stage 1 GC patients (>0.72) and odds ratio of GC for high-risk subjects (>3.93). The likelihood that surveillance is the most cost-effective strategy is 69.5% accounting for model uncertainties. CONCLUSION: Endoscopic surveillance of gastric premalignancies can be a cost-effective strategy for GC prevention. Its implementation requires careful assessment on factors influencing the actual cost-effectiveness.

[Cellular Uptake and Localization of Novel NSCLC Penetrating Peptide with Neuropilin-1 Binding Motif].

OBJECTIVE: To synthesize and study the specific binding affinity of tumor-penetrating peptide YCCS to non-small cell lung carcinoma (NSCLC) cells in vitro. METHODS: YCCS peptide was designed by fusing the neuropilin-1 (NRP-1) binding sequence and NSCLC binding peptide CS. YCCS peptide was synthesized and fluorescent labeled with N-terminal FITC. NRP-1 positive human NSCLC cell A549, NRP-1 positive human breast cancer cell MDA-MB-231, normal human bronchial epithelium HBE135-E6E7 and human liver cell HL-7702 were incubated respectively, then we observed the specific binding affinity of tumor-penetrating peptide YCCS to NSCLC cells. RESULTS: After treated with 5 µmol/L peptide, significant fluorescent signals of FITC-YCCS peptide were demonstrated only in NSCLC A549 cells but marginal captured signal in MDA-MB-231, normal human HBE135-E6E7 or HL-7702 cells, which revealed specific NSCLC cells binding affinity. In 20 µmol/L treated group, non-specific binding were found in MDA-MB-231 and HL-7702 cells. CONCLUSION: The results of this novel designed YCCS peptide indicated a promising strategy for improving tumor penetrating with delivery capability of drugs to NSCLC A549 cells when treated with 5 µmol/L peptide.

p8 attenuates the apoptosis induced by dihydroartemisinin in cancer cells through promoting autophagy.

Dihydroartemisinin (DHA) exhibits anticancer activities in a variety of cancer cells, but DHA alone are not effective enough for cancer therapy. In this study we found the stress-regulated protein p8 was obviously increased after DHA treatment in several cancer cells, which further to induce autophagy by the upregulation of endoplasmic reticulum stress-related protein ATF4 and CHOP. Furthermore, when we silenced p8 by siRNA in cancer cells, the apoptosis induced by DHA were notably increased, whereas the overexpression of p8 in cancer cells leaded to the resistance to DHA-induced apoptosis. Moreover, we found the inhibition of autophagy with chloroquine (CQ) can enhance the anticancer effect of DHA both in vitro and in vivo. In conclusion, we found that p8-mediated autophagy attenuates DHA-induced apoptosis in cancer cells, which provides evidence to support the use p8 as a cancer therapeutic target, and suggests that the combination treatment with DHA and autophagy inhibitor might be an effective cancer therapeutic strategy.

Dihydroartemisinin induces autophagy by suppressing NF-κB activation.

Nuclear factor-kappa B (NF-κB) and autophagy are two major regulators involved in both tumor initiation and progression. However, the association between these two signaling pathways still remains obscure. In this work, we demonstrate that dihydroartemisinin (DHA) stimulates the induction of autophagy in several cancer cell lines through repression of NF-κB activity. We also show that inhibiting NF-κB results in an accumulation of reactive oxygen species (ROS), which participate in the stimulation of autophagy. These findings present a pathway by which DHA promotes autophagy in cancer cells and provide evidence for the DHA-induced sensitization effect of some chemotherapeutics.

Empirical evidence of the continuing improvement in cost efficiency of an endoscopic surveillance programme for gastric cancer in Singapore from 2004 to 2010.

BACKGROUND: Endoscopic surveillance has been proven effective in prolonging the survival of gastric cancer (GC) patients. However, there is limited evidence on the cost efficiency of delivering this intervention, especially on a national level in spite of cost efficiency being a major determinant of the actual cost-effectiveness of a cancer prevention programme. The Singapore Gastric Cancer Epidemiology Clinical and Genetic Programme (GCEP) is a demonstration project offering scheduled endoscopy to the Chinese population aged 50 years or older in Singapore. By assessing the cost efficiency of the GCEP, this study aimed to provide empirical evidence on the cost structure and mechanisms underlying cost generation in conducting GC surveillance, thus informing resource allocation and programme budgeting for the Singapore government. METHODS: From a societal perspective, we reported on the direct cost (resource consumption) of conducting endoscopic surveillance through the GCEP network. We retrospectively collected individual-level data of 216 subjects recruited at the National University Hospital, Singapore from 01/04/2004 to 31/10/2010. The Overall Cost, Clinical Cost, GCEP Cost and Personal Cost incurred in serving one subject was computed and discounted as 2004 US dollar (US$) per capita for every year. The Generalized Estimation Equation (GEE) was used to model the data. RESULTS: All cost indices continuously declined over the 6.5-year costing period. For the total sample, Overall Cost, Clinical Cost, GCEP Cost and Personal Cost declined by 42.3%, 54.1%, 30% and 25.7% respectively. This downward trend existed for age and gender subgroups and the high risk group only with cost reductions varying between 3.5% and 58.4%. The GEE models confirmed statistical significance of the downward trend and of its association with risk profile, where the moderate risk group had cost indices at most 77% of the high risk group. CONCLUSIONS: Our study offered empirical evidence of improved cost efficiency of a surveillance programme for GC in the early phase of programme implementation. Mechanisms such as economies of scale and self-learning were found to be involved in the cost reduction. Our findings highlighted the importance of assessing the cost efficiency and offered valuable insights for future programme budgeting and policy making.

DHA regulates angiogenesis and improves the efficiency of CDDP for the treatment of lung carcinoma.

Dihydroartemisinin (DHA), a semisynthetic derivative of artemisinin, has been shown to exhibit anti-angiogenic and anti-tumor effects apart from its antimalarial activity. In this study, we demonstrate that the combined treatment of cisplatin (CDDP) and DHA exerts a strong, synergistic anti-proliferative effect in human lung carcinoma cells, including A549 and A549/DDP cells, with an average combination index below 0.7. Moreover, the in vivo anti-tumor efficacy of CDDP treatment was increased by DHA. The enhanced anti-cancer activities were also accompanied by reduced tumor microvessel density, increased CDDP concentration within A549 and A549/DDP xenograft BALB/c athymic mice models and suppressed expression of the vascularization-related proteins HIF-1α and VEGF both in vivo and in vitro. Furthermore, the level of apoptosis in the tumor cells increased with the combined treatment of DHA and CDDP. Taken together, our results indicate that a combination of DHA and CDDP treatments synergistically affects tumor angiogenesis, and these results provide a clear rationale for the investigation of these drugs in future clinical trials.

Laparoscopic drainage of cryptogenic liver abscess.

BACKGROUND: To retrospectively compare the outcomes of percutaneously drained and laparoscopically drained liver abscesses. METHODS: Eight-five consecutive patients with radiological evidence of liver abscess were treated at National University Hospital of Singapore from 2005 to 2011. Multivariable logistic regression was used to identify failures of intervention. This was defined as persistent objective signs of sepsis. Complications, length of antibiotic therapy, and hospital stay were recorded but not used as indicators for failure of intervention. A propensity score analysis was used to adjust for possible confounders. RESULTS: Twenty-seven (40.3%) patients in the percutaneous group did not respond to primary intervention compared to 2 patients (11.1%) in the laparoscopic group (p = 0.020). Two patients within the percutaneous group died from progression of sepsis despite intervention. In the multivariate model with propensity score, laparoscopic drainage had a protective effect against failure compared to percutaneous drainage of liver abscess (odds ratio [OR], 0.03; 95% confidence interval [CI], [0-0.4]; p = 0.008). There were no differences in complications related to the intervention (p = 0.108). Mean duration of antibiotics (p = 0.437) and hospital stay (p = 0.175) between the groups was similar. CONCLUSIONS: Laparoscopic drainage of cryptogenic liver abscesses should be considered as an option for drainage of liver abscess.

A cost-effectiveness analysis evaluating endoscopic surveillance for gastric cancer for populations with low to intermediate risk.

BACKGROUND: Gastric cancer (GC) surveillance based on oesophagogastroduodenoscopy (OGD) appears to be a promising strategy for GC prevention. By evaluating the cost-effectiveness of endoscopic surveillance in Singaporean Chinese, this study aimed to inform the implementation of such a program in a population with a low to intermediate GC risk. METHODS: USING A REFERENCE STRATEGY OF NO OGD INTERVENTION, WE EVALUATED FOUR STRATEGIES: 2-yearly OGD surveillance, annual OGD surveillance, 2-yearly OGD screening and 2-yearly screening plus annual surveillance in Singaporean Chinese aged 50-69 years. From a perspective of the healthcare system, Markov models were built to simulate the life experience of the target population. The models projected discounted lifetime costs ($), quality adjusted life year (QALY), and incremental cost-effectiveness ratio (ICER) indicating the cost-effectiveness of each strategy against a Singapore willingness-to-pay of $46,200/QALY. Deterministic and probabilistic sensitivity analyses were used to identify the influential variables and their associated thresholds, and to quantify the influence of parameter uncertainties respectively. RESULTS: With an ICER of $44,098/QALY, the annual OGD surveillance was the optimal strategy while the 2-yearly surveillance was the most cost-effective strategy (ICER = $25,949/QALY). The screening-based strategies were either extendedly dominated or cost-ineffective. The cost-effectiveness heterogeneity of the four strategies was observed across age-gender subgroups. Eight influential parameters were identified each with their specific thresholds to define the choice of optimal strategy. Accounting for the model uncertainties, the probability that the annual surveillance is the optimal strategy in Singapore was 44.5%. CONCLUSION: Endoscopic surveillance is potentially cost-effective in the prevention of GC for populations at low to intermediate risk. Regarding program implementation, a detailed analysis of influential factors and their associated thresholds is necessary. Multiple strategies should be considered in order to recommend the right strategy for the right population.

Validation of the functional assessment of cancer therapy-gastric module for the Chinese population.

BACKGROUND: Quality of life (QoL) assessment has become an important aspect of the clinical management of gastric cancer (GC), which poses a greater health threat in Chinese populations around the world. Functional Assessment of Cancer Therapy-Gastric Module (FACT-Ga), a questionnaire developed specifically to measure QoL of patients with GC, has never been validated in Chinese subjects. The current study was designed to examine the psychometric properties of FACT-Ga as a GC specific QoL instrument for its future use in Chinese populations. METHODS: A sample of 67 Chinese patients with GC in the National University Hospital, Singapore was investigated cross-sectionally. The participants independently completed either English or Chinese versions of the FACT-Ga and the European Quality of Life-5 Dimensions (EQ-5D). Reliability was measured as the Cronbach's α for EQ-5D, and five subscale scores and two total scores of FACT-Ga. The sensitivity to patients' clinical status was evaluated by comparing EQ-5D and FACT-Ga scores between clinical subgroups classified by Clinical Stage and Treatment Intent. The construct validity of FACT-Ga was assessed internally by examining the item-to-scale correlations and externally by contrasting the FACT-Ga subscales with the EQ-5D domains. RESULTS: For both FACT-Ga and EQ-5D, patients treated with curative intent rated their QoL higher than those treated for palliation, and early stage patients scored higher than those in the late stage. The sensitivity to clinical status of FACT-Ga scores were differential as four of seven FACT-Ga scores were significant for Treatment Intent while only one subscale score was significant for Clinical Stage. Six FACT-Ga scores had Cronbach's α of 0.8 or above indicating excellent reliability. For construct validity, 45 of 46 items converged about their respective subscales. The monotrait-multimethod correlations between QoL constructs of FACT-Ga and EQ-5D were stronger than the multitrait-multimethod correlations as theoretically hypothesized, suggesting good convergent and discriminant validities. CONCLUSIONS: Given the excellent reliability and good construct validity, FACT-Ga scores are able to distinguish patient groups with different clinical characteristics in the expected direction. Therefore FACT-Ga can be used as a discriminative instrument for measuring QoL of Chinese patients with GC.

Dihydroartemisinin induces autophagy and inhibits the growth of iron-loaded human myeloid leukemia K562 cells via ROS toxicity.

Dihydroartemisinin (DHA), an active metabolite of artemisinin derivatives, is the most remarkable anti-malarial drug and has little toxicity to humans. Recent studies have shown that DHA effectively inhibits the growth of cancer cells. In the present study, we intended to elucidate the mechanisms underlying the inhibition of growth of iron-loaded human myeloid leukemia K562 cells by DHA. Mitochondria are important regulators of both autophagy and apoptosis, and one of the triggers for mitochondrial dysfunction is the generation of reactive oxygen species (ROS). We found that the DHA-induced autophagy of leukemia K562 cells, whose intracellular organelles are primarily mitochondria, was ROS dependent. The autophagy of these cells was followed by LC3-II protein expression and caspase-3 activation. In addition, we demonstrated that inhibition of the proliferation of leukemia K562 cells by DHA is also dependent upon iron. This inhibition includes the down-regulation of TfR expression and the induction of K562 cell growth arrest in the G2/M phase.

Dihydroartemisinin improves the efficiency of chemotherapeutics in lung carcinomas in vivo and inhibits murine Lewis lung carcinoma cell line growth in vitro.

PURPOSE: Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, has exhibited the strongest antimalarial activity among the derivatives of artemisinin. There is growing evidence that DHA has some impact against tumors. Our purpose was to evaluate in vitro antitumoral properties of DHA in the murine Lewis lung carcinoma (LLC) cell line. At the same time, we observed the therapeutic effect of DHA combined with cyclophosphamide (CTX) in the LLC and combined with cisplatin (CDDP) in the human non-small cell lung cancer A549 xenotransplanted carcinoma in vivo. METHODS: Cytotoxicity was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method, apoptosis was measured by AO/EB double staining and flow cytometry. The expression of vascular endothelial growth factor (VEGF) receptor KDR/flk-1 was analyzed by western blotting and RT-PCR. In vivo activity of DHA combined with CTX or CDDP was assayed through tumor growth and metastasis. RESULTS: Dihydroartemisinin exhibited high anti-cancer activity in LLC cell line. DHA also induced apoptosis of LLC cells and influenced the expression of VEGF receptor KDR/flk-1. Furthermore, in both tumor xenografts, a greater degree of growth inhibition was achieved when DHA and chemotherapeutics were used in combination. The affection by DHA combined CTX on LLC tumor metastasis was significant. CONCLUSIONS: Dihydroartemisinin is a potent compound against LLC cell line in vitro. In vivo, the combination strategy of DHA and chemotherapeutics holds promise for the treatment of relatively large and rapidly growing lung cancers.

WITHDRAWN: The effect of dihydroartemisinin on TfR and VEGF expression in iron overload human myeloid leukemia K562 cells.

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[Dihydroartemisinin down-regulates the expression of transferrin receptor in myeloid leukemia cells].

This article reports the effect of dihydroartemisinin (DHA) on transferrin receptor (TfR) in myeloid leukemia cells by establishing the model of normal iron HL60 and K562 cells and iron overload K562 cells in vitro. The TfR content of myeloid leukemia cells was determined by flow cytometry, and the effect of DHA on iron content in K562 cells was determined by atomic absorption spectrophotometric analysis. Furthermore, the inhibitory effect of DHA on the anti-proliferation and expression of TfR protein and mRNA in myeloid leukemia cells was studied. As a result, DHA effectively decreased the TfR content and down-regulated TfR protein expression in normal iron HL60 and K562 cells in a dose- and time-dependent manner and inhibited the cell proliferation. The IC50 were 1.74 and 11.33 micromol x L(-1), respectively. DHA exerted more pronounced inhibitory action on expression of TfR protein and mRNA in iron overload K562 cells. Compared to normal iron K562 cells, the TfR protein and mRNA levels were lowered by 28.1% (P < 0.01) and 26. 2% (P < 0. 05) , respectively, after DHA treatment for 48 h in iron overload K562 cells. Moreover, DHA decreased the iron content of iron overload K562 cells and inhibited the proliferation of iron overload K562 cells more potently. DHA effectively down-regulated the TfR content as well as expression of TfR protein and mRNA in normal iron myeloid leukemia cells. DHA also inhibited the proliferation of HL60 and K562 cells. The anti-proliferation effect of DHA on iron overload K562 cells was more striking.

Dihydroartemisinin induces apoptosis in human leukemia cells HL60 via downregulation of transferrin receptor expression.

Dihydroartemisinin (DHA), a water-soluble active metabolite of artemisinin derivatives, is the safest and most effective antimalarial analog of artemisinin. In the present investigation, we assessed the apoptotic effect of DHA on leukemia HL60 cells and its regulation of transferrin receptor (TfR). Cell growth inhibition was assessed by Trypan blue exclusive staining; the expression of caspase-3, Bcl-2, and Bax in HL60 cells was evaluated by Western blotting; DHA-induced apoptosis was determined by AO/EB double staining, DNA fragmentation assay, and flow cytometric analysis; the expression of TfR in HL60 cells was examined by real-time PCR assays, Western blotting, and flow cytometric analysis. DHA could specifically reduce the mRNA and protein expression of TfR in HL60 cells, and the flow cytometric analysis presented the unity tendency that the TfR content decreased progressively in a dose-dependent manner. Consequently, DHA exhibited high anticancer activity in HL60 cells; MTT assay and growth inhibition assay showed that DHA could specifically inhibit the growth of HL60 cells in a dose-dependent (0.25-8 micromol/l) and time-dependent (12-72 h) manner. DHA-induced DNA fragmentation also induced the activation of caspase-3 and influenced the expression of Bcl-2 and Bax. Taken together, these data from our study show that DHA can induce HL60 cell apoptosis via the effect of downregulation TfR expression resulting in an induction of apoptosis through the mitochondrial pathway, and it might be a potential antileukemia strategy for leukemia therapy.

Artesunate inhibits angiogenesis and downregulates vascular endothelial growth factor expression in chronic myeloid leukemia K562 cells.

Artesunate (ART), a semi-synthetic derivative of artemisinin extracted from the Chinese herb Artemisia annua, is a safe and effective antimalarial drug. In the present investigation, we analyzed the inhibitory effects of ART on angiogenesis and on VEGF production in chronic myeloid leukemia (CML) K562 cells in vitro and in vivo. In order to analyze the effect of ART on VEGF secretion in K562 cells, we examined the level of VEGF secreted in conditioned media (CM) by ELISA assay. The result showed that ART could decrease the VEGF level in CM of K562 cells, even at a lower concentration (2 micromol/l, P<0.01). The inhibitory effect of in vitro angiogenesis was tested on aortic sprouting in fibrin gel. ART could effectively suppress the stimulating angiogenic ability of CM by pretreated with K562 cells for 48 h in a time-dependent manner (days 3-14). The antiangiogenic effect of ART was further evaluated in vivo in chicken chorioallantoic membrane (CAM) neovascularization model. The result indicated that the stimulating angiogenic activity was decreased in response to the K562 cells treated with ART or the CM from K562 cells pretreated with ART in a dose-dependent manner (3-12 micromol/l). Furthermore, we analyzed the level of VEGF expression by western blot and detected the form of VEGF mRNA by RT-PCR in K562 cells. The experiments showed that ART could inhibit the VEGF expression, correlated well with the level of VEGF secreted in CM. These findings suggest that ART might present potential antileukemia effect as a treatment for CML therapy, or as an adjunct to standard chemotherapeutic regimens.

Dihydroartemisinin inhibits angiogenesis induced by multiple myeloma RPMI8226 cells under hypoxic conditions via downregulation of vascular endothelial growth factor expression and suppression of vascular endothelial growth factor secretion.

Multiple myeloma remains incurable to date; therefore, new biologically target-based therapies are urgently needed. Our previous studies have showed that the antimalarial dihydroartemisinin possessed antiangiogenic activity in solid tumors. The present study evaluated the effect of dihydroartemisinin on human multiple myeloma-induced angiogenesis under hypoxia and elucidated its mechanism of action. An in-vivo chicken chorioallantoic membrane model was used to examine the effect of dihydroartemisinin on multiple myeloma-induced angiogenesis. Compared with conditioned medium of control, conditioned medium from human multiple myeloma RPMI8226 cells pretreated with 3 micromol/l dihydroartemisinin in hypoxia was observed to reduce microvessel growth on chicken chorioallantoic membranes by approximately 28.6% (P<0.05). The level of vascular endothelial growth factor in conditioned medium was determined by enzyme-linked immunosorbent assay. The results confirmed that 3 micromol/l dihydroartemisinin could significantly decrease vascular endothelial growth factor secretion by RPMI8226 cells (P<0.05), which correlated well with the reduction of multiple myeloma-induced angiogenesis on chicken chorioallantoic membranes. Western blot and reverse transcription-polymerase chain reaction results revealed that dihydroartemisinin downregulated the expression of vascular endothelial growth factor in RPMI8226 cells in hypoxia. In addition, we demonstrated that dihydroartemisinin reduced extracellular signal-regulated kinase 1/2 activation and inhibited growth of RPMI8226 cells under hypoxic conditions. Therefore, we concluded that dihydroartemisinin, which is already used to treat malaria and is well tolerated, possesses potential as an antiangiogenic drug in multiple myeloma therapy and thereby may improve patient outcome.