Impact of Ionic Liquids on the Physicochemical Behavior of Vesicles.

The effects of two ionic liquids (ILs), 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) and 1-butyl-1-methyl pyrrolidinium tetrafluoroborate ([bmp]BF4), on a mixture of phospholipids (PLs) 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC), 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE), and 1,2-dipalmitoyl-sn-glycero-3-phosphoglycerol (DPPG) (6:3:1, M/M/M, 70% PL) in combination with 30 mol % cholesterol (CHOL) were investigated in the form of a solvent-spread monolayer and bilayer (vesicle). Surface pressure (π)-area (A) isotherm studies, using a Langmuir surface balance, revealed the formation of an expanded monolayer, while the cationic moiety of the IL molecules could electrostatically and hydrophobically bind to the PLs on the palisade layer. Turbidity, dynamic light scattering (size, ζ-potential, and polydispersity index), electron microscopy, small-angle X-ray/neutron scattering, fluorescence spectroscopy, and differential scanning calorimetric studies were carried out to evaluate the effects of IL on the structural organization of bilayer in the vesicles. The ILs could induce vesicle aggregation by acting as a "glue" at lower concentrations (<1.5 mM), while at higher concentrations, the ILs disrupt the bilayer structure. Besides, ILs could result in the thinning of the bilayer, evidenced from the scattering studies. Steady-state fluorescence anisotropy and lifetime studies suggest asymmetric insertion of ILs into the lipid bilayer. MTT assay using human blood lymphocytes indicates the safe application of vesicles in the presence of ILs, with a minimal toxicity of up to 2.5 mM IL in the dispersion. These results are proposed to have applications in the field of drug delivery systems with benign environmental impact.

Physicochemical Studies on Amino Acid Based Metallosurfactants in Combination with Phospholipid.

Dicarboxylate metallosurfactants (AASM), synthesized by mixing N-dodecyl aminomalonate, -aspartate and -glutamate with CaCl2, MnCl2 and CdCl2, were characterized by XRD, FTIR, and NMR spectroscopy. Layered structures, formed by metallosurfactants, were evidenced from differential scanning calorimetry and thermogravimetric analyses. Solvent-spread monolayer of AASM in combination with soyphosphatidylcholine (SPC) and cholesterol (CHOL) were studied using Langmuir surface balance. With increasing mole fraction of AASM mean molecular area increased and passed through maxima at ~60 mol% of AASMs, indicating molecular packing reorganization. Systems with 20 and 60 mol% AASM exhibited positive deviations from ideal behavior signifying repulsive interaction between the AASM and SPC, while synergistic interactions were established from the negative deviation at other combinations. Dynamic surface elasticity increased with increasing surface pressure signifying formation of rigid monolayer. Transition of monolayer from gaseous to liquid expanded to liquid condensed state was established by Brewster angle microscopic studies. Stability of the hybrid vesicles, formed by AASM+SPC+CHOL, was established by monitoring their size, zeta potential and polydispersity index values over 100 days. Size and spherical morphology of hybrid vesicles were confirmed by transmission electron microscopic studies. Biocompatibility of the hybrid vesicles were established by cytotoxicity studies revealing their possible applications in drug delivery and imaging.

COVID-19 pandemic impact on primary immunization uptake.

Purpose/Background: Pediatricians across the world are seeing a steep drop in the number of children coming in for appointments due to COVID-19 pandemic. To prevent outbreaks of serious diseases that pose an even greater threat to children than COVID-19, it is important that children not skip their routine vaccines. The aim of this study was to determine the impact of COVID-19 pandemic on primary immunization activities in Saudi Arabia. Settings and Design: Cross-sectional design. Methods and Material: The study was conducted at a community pediatric clinic. All parents of preschool-age children who visited the community pediatric clinics were asked to complete a self-administrated questionnaire on primary immunization uptake during the pandemic. Statistical Analysis Used: The Chi-square and Fisher's exact test were performed to examine the demographic differences between participants who missed vaccination during the pandemic and reasons for missing the vaccination. Results: Three hundred study participants completed our questionnaire. In total, 90.6% of respondents were up to date with their vaccinations prior to the pandemic, and most respondents believed that children should be immunized at an appropriate age, it is essential for children to be fully immunized, vaccination is effective in preventing serious disease, and childhood immunization is essential during the pandemic (98.3%, 98.7%, 97.3%, and 93.7%, respectively). In total, 72.4% of respondents did not miss their vaccinations during the pandemic, while 26.6% missed vaccinations. The most common reason for missing vaccinations during the pandemic was transportation difficulty and curfew, followed by fear of contracting COVID-19 infection (40.9% and 35.5%, respectively). Those who did not believe that childhood immunization was necessary during the pandemic were more likely to miss vaccinations during the pandemic (P < 0.001). In addition, those who did not have a family member with COVID-19 infection were more likely not to miss the vaccine (P < 0.001). Moreover, those who thought taking vaccinations in a primary care setting or hospital is safe were more likely not to miss the vaccination during the pandemic (P < 0.027) and (P < 0.001). Conclusions: Significant portion of the population was affected and missed immunizations during the pandemic. The perceptions on the importance of immunization and having a family member affected with COVID-19 during the pandemic were important factors in missing immunizations. Moreover, transportation and fear of contracting COVID-19 during the curfew were also common reasons for missing immunizations during the pandemic.

An integrated in-silico Pharmaco-BioInformatics approaches to identify synergistic effects of COVID-19 to HIV patients.

BACKGROUND: With high inflammatory states from both COVID-19 and HIV conditions further result in complications. The ongoing confrontation between these two viral infections can be avoided by adopting suitable management measures. PURPOSE: The aim of this study was to figure out the pharmacological mechanism behind apigenin's role in the synergetic effects of COVID-19 to the progression of HIV patients. METHOD: We employed computer-aided methods to uncover similar biological targets and signaling pathways associated with COVID-19 and HIV, along with bioinformatics and network pharmacology techniques to assess the synergetic effects of apigenin on COVID-19 to the progression of HIV, as well as pharmacokinetics analysis to examine apigenin's safety in the human body. RESULT: Stress-responsive, membrane receptor, and induction pathways were mostly involved in gene ontology (GO) pathways, whereas apoptosis and inflammatory pathways were significantly associated in the Kyoto encyclopedia of genes and genomes (KEGG). The top 20 hub genes were detected utilizing the shortest path ranked by degree method and protein-protein interaction (PPI), as well as molecular docking and molecular dynamics simulation were performed, revealing apigenin's strong interaction with hub proteins (MAPK3, RELA, MAPK1, EP300, and AKT1). Moreover, the pharmacokinetic features of apigenin revealed that it is an effective therapeutic agent with minimal adverse effects, for instance, hepatoxicity. CONCLUSION: Synergetic effects of COVID-19 on the progression of HIV may still be a danger to global public health. Consequently, advanced solutions are required to give valid information regarding apigenin as a suitable therapeutic agent for the management of COVID-19 and HIV synergetic effects. However, the findings have yet to be confirmed in patients, suggesting more in vitro and in vivo studies.

Attitude and hesitancy of human papillomavirus vaccine among Saudi parents.

Background: Human papillomavirus (HPV) is closely associated with cervical cancer. The HPV vaccine is expected to protect against two-thirds of cervical cancer cases in Saudi Arabia. Objectives: To determine the awareness and attitude regarding the HPV vaccine among Saudi parents attending family medicine clinics in Riyadh. Materials and Methods: All Saudi parents of patients of Family Medicine Pediatric Clinics, King Faisal Specialist Hospital and Research Centre (KFSH&RC), Riyadh, were invited to participate in this study between November 2019 and May 2020. A culturally sensitive and specially designed questionnaire was administered using an interview-based model. The data collected included sociodemographic information, knowledge of HPV and its vaccine, and attitudes regarding HPV acceptance. Results: A total of 296 study participants completed our questionnaire on the HPV vaccine. About 70.6% of the participants were not aware of the HPV vaccine and the majority of them either did not know or did not associate HPV as an etiology for cervical cancer (38.8 and 37.8%, respectively). Only 28.6% of the participants were aware that cervical cancer can be prevented by a vaccine and 89.5% of the study participants did not receive the HPV vaccine for themselves or their children. The employee status was significantly associated with a history of receiving the HPV vaccine (χ2 (2) = 10.607, P =0.005), while age and the level of education had a statistically significant relationship with planning on having the HPV vaccine ((χ2 (9) = 51.841, P <.001) and (χ2 (12) = 23.977, P =0.02), respectively). The level of awareness of the HPV vaccine was significantly associated with a history of having the HPV vaccine; (χ2 (1) = 38.486, P <.001) as well as with planning on having the HPV vaccine (χ2 (1) = 38.486, P <.001). Moreover, the reasons for hesitancy were a statistically significant factor for unvaccinated respondents who were not planning to have the HPV vaccine (χ2 (21) = 97.689, P <.001) while it was not significantly associated with the unvaccinated respondents who were planning to have the HPV vaccine (χ2 (9) = 6.989, P =.63). Conclusion: Our study clearly demonstrated a poor level of awareness and attitude toward the HPV vaccine among Saudi parents. A higher level of awareness of the HPV vaccine was significantly associated with planning on having the vaccine. There is a need for effective awareness programs for better HPV-related education in order to increase the acceptance of the HPV vaccine among Saudi parents.

Chemotherapeutic Activities of Dietary Phytoestrogens against Prostate Cancer: From Observational to Clinical Studies.

Prostate cancer remains one of the most frequent and deadliest malignancies in males, where the rate of disease progression is closely associated with the type of dietary intake, specifically a Western-style diet. Indeed intake of the Asian diet, which contains abundant phytoestrogens, is inversely correlated with a higher risk of prostate cancer, suggesting a chemoprotective effect of phytoestrogen against cancer progression. Although the role of phytoestrogens in cancer treatment has been well documented, their impact on prostate cancer is not well understood. Therefore, the present review discusses the possible chemopreventive effect of phytoestrogens, emphasizing their efficacy at the different stages of carcinogenesis. Furthermore, phytoestrogens provide a cytoprotective effect in conventional chemotherapy and enhance chemosensitivity to tumor cells, which have also been discussed. This compilation provides a solid basis for future research on phytoestrogens as a promising avenue for anticancer drug development and also recommends these beneficiary compounds in the daily diet to manage and prevent prostate cancer.

Chemotherapeutic potential of hesperetin for cancer treatment, with mechanistic insights: A comprehensive review.

BACKGROUND: Cancer has become a significant concern in the medical sector with increasing disease complexity. Although some available conventional treatments are still a blessing for cancer patients, short-and long-term adverse effects and poor efficiency make it more difficult to treat cancer patients, demonstrating the need for new potent and selective anticancer drugs. In search of potent anticancer agents, naturally occurring compounds have always been admired due to their structural diversity, where Hesperetin (HSP) may be one of the potent candidates. PURPOSE: We aimed to summarize all sources, pharmacological properties, anticancer activities of HSP against numerous cancers types through targeting multiple pathological processes, mechanism of HSP on sensitizing the current anti-cancer agents and other phytochemicals, overcoming resistance pattern and determining absorption, distribution, metabolism, excretion, and toxicity (ADME/Tox). METHODS: Information was retrieved from PubMed, Science Direct, and Google Scholar based on some key points like Hesperetin, cancer name, anticancer resistance, nanoformulation, and ADME/Tox was determined by in silico approaches. RESULT: HSP is a phytoestrogen present in citrus fruits in a high concentration (several hundred mg/kg) and exhibited anti-cancer activities through interfering at several pathways. HSP can suppress tumor formation by targeting several cellular proteins such as cell cycle regulatory, apoptosis, metastatic, tyrosine kinase, growth factor receptor, estrogen metabolism, and antioxidant-related protein.HSP has shown remarkable synergistic properties in combination therapy and has been reported to overcome multidrug cancer resistance drugs, leading to an improved defensive mechanism. These anticancer activities of HSP may be due to proper structural chemistry. CONCLUSION: Overall, HSP showed potential anticancer activities against all cancer and possess better pharmacokinetic properties. So this phytochemical alone or combination with other agents can be an effective alternative drug for cancer treatment.

Micro-structural investigations on oppositely charged mixed surfactant gels with potential dermal applications.

Dicarboxylic amino acid-based surfactants (N-dodecyl derivatives of -aminomalonate, -aspartate, and -glutamate) in combination with hexadecyltrimethylammonium bromide (HTAB) form a variety of aggregates. Composition and concentration-dependent mixtures exhibit liquid crystal, gel, precipitate, and clear isotropic phases. Liquid crystalline patterns, formed by surfactant mixtures, were identified by polarizing optical microscopy. FE-SEM studies reveal the existence of surface morphologies of different mixed aggregates. Phase transition and associated weight loss were found to depend on the composition where thermotropic behaviours were revealed through combined differential scanning calorimetry and thermogravimetric studies. Systems comprising more than 60 mol% HTAB demonstrate shear-thinning behaviour. Gels cause insignificant toxicity to human peripheral lymphocytes and irritation to bare mouse skin; they do not display the symptoms of cutaneous irritation, neutrophilic invasion, and inflammation (erythema, edema, and skin thinning) as evidenced by cumulative irritancy index score. Gels also exhibit substantial antibacterial effects on Staphylococcus aureus, a potent causative agent of skin and soft tissue infections, suggesting its possible application as a vehicle for topical dermatological drug delivery.

Interfacial and Aggregation Behaviour of Sodium Dodecyl Sulphate Induced by Ionic Liquids.

Aggregation studies of anionic surfactant sodium dodecyl sulphate (SDS) was investigated in aqueous 1-butyl-3-methylimidazolium chloride [bmim]Cl and N-butyl-N-methyl pyrrolidinium tetrafluoroborate [bmp]BF4 ionic liquid (IL) solutions respectively. Systems were studied by surface tension, conductance, UV-VIS absorption/emission spectroscopy and dynamic light scattering. Critical micelle concentration (CMC) values gradually decreased with increasing IL concentration which indicates synergistic interaction between ILs and SDS. Gibbs free energy change results demonstrated spontaneous micellization induced by ILs; however the effect of ILs were not similar to the corresponding regular salts (NaCl and NaBF4). Aggregation number (n) of micelles, determined by fluorescence quenching method, indicate that the 'n' values increase with increasing ILs concentration, induced by the oppositely charged IL cation. Size of the micelles, determined by dynamic light scattering studies, increased with increasing ILs concentration, which were due to the formation of larger aggregates; the aggregates are considered to be comprised of the anionic surfactant with a substantial proportion of ILs cation as the bound counter ions. Such studies are considered to shed further light in the fundamentals of IL induced micellization as well as in different practical applications.

Lipid Profile of Children Suffering from Pediatric Rheumatic Diseases (pRDS).

BACKGROUND: Aim of this study was to assess the lipid status of the patients of pediatric rheumatologic diseases (pRDS). METHODS: This observational study was carried out in the department of pediatrics, Khulna medical college hospital, Bangladesh for a period of one year. Total 23 patients were included in this study. These new cases were diagnosed according to the ILAR, ACR, and EULAR criteria. Early morning blood samples were sent to the laboratory for the assessment of lipid status (TC, TG, HDL, and LDL). These values were collected and statistically recorded. RESULTS: Total new cases of pRDS were 23. Among them JIA was 15, SLE 4, and Vasculitis 4 in number. HSP was in 3 and KD in 1 cases of vasculitis group. Male/ Female ratio is 1.6:1. Mean age of the diseases were 8.54 years. TC, and TG was found in significant level in 4(17.4%), and 12(52.8%) pRDS cases respectively. HDL was observed of risk level in 4(17.3%) patients. LDL was observed normal in all the patients. TG was found of significant level in 7(46.7%) JIA, 3(75%) SLE and 2 (50%) vasculitis patients. CONCLUSION: TG was the lipid observed in significant level in majority of the new pRDS cases. Elevated TG might be considered as an index of disease activity in all cases of pRDS. Measures could be adopted in all pRDS to control the lipid status from the beginning of illness to reduce the complications from dyslipidemia like atherosclerosis and cardiovascular morbidity and mortality in future.

In vitro antiretroviral activity and in vivo toxicity of the potential topical microbicide copper phthalocyanine sulfate.

BACKGROUND: Copper has antimicrobial properties and has been studied for its activity against viruses, including HIV. Copper complexed within a phthalocyanine ring, forming copper (II) phthalocyanine sulfate (CuPcS), may have a role in microbicide development when used intravaginally. METHODS: CuPcS toxicity was tested against cervical epithelial cells, TZM-BL cells, peripheral blood mononuclear cells (PBMC), and cervical explant tissues using cell viability assays. In vivo toxicity was assessed following intravaginal administration of CuPcS in female BALB/C mice and measured using a standardized histology grading system on reproductive tract tissues. Efficacy studies for preventing infection with HIV in the presence of various non-toxic concentrations of CuPcS were carried out in TZM-BL, PBMC, and cervical explant cultures using HIV-1BAL and various pseudovirus subtypes. Non-linear regression was applied to the data to determine the EC50/90 and CC50/90. RESULTS: CuPcS demonstrated inhibition of HIV infection in PBMCs at concentrations that were non-toxic in cervical epithelial cells and PBMCs with EC50 values of approximately 50 µg/mL. Reproductive tract tissue analysis revealed no toxicity at 100 mg/mL. Human cervical explant tissues challenged with HIV in the presence of CuPcS also revealed a dose-response effect at preventing HIV infection at non-toxic concentrations with an EC50 value of 65 µg/mL. CONCLUSION: These results suggest that CuPcS may be useful as a topical microbicide in concentrations that can be achieved in the female genital tract.

Sex worker activism, feminist discourse and HIV in Bangladesh.

This paper explores the relationship between sex worker activism and HIV-related discourse in Bangladesh, relating recent developments in activism to the influence of feminist thought. Following their eviction in 1991 from brothels from red light areas, Bangladeshi sex workers started a social movement, at just about the same time that programmes started to work with sex workers to reduce the transmission of HIV. This paper argues that both sex worker activism and HIV-prevention initiatives find impetus in feminist pro-sex-work perspectives, which place emphasis on individual and collective agency. However, by participating in these programmes, sex workers failed to contest the imagery of themselves as 'vectors' of HIV. In this way, they were unwittingly complicit in reproducing their identity as 'polluting others'. Moreover, by focusing on individual behaviour and the agency of sex workers, HIV programmes ignored the fact that the 'choices' made by sex workers are influenced by a wide range of structural and discursive factors, including gender norms and notions of bodily purity, which in turn have implications for the construction of HIV-related risk.

The effects of 17-ß estradiol on enhancing proliferation of human bone marrow mesenchymal stromal cells in vitro.

Human bone marrow mesenchymal stromal cells (MSCs) with self-renewal and multiple differentiation potentials are considered a possible cell source for tissue engineering and regenerative medicine. However, the limited amount of MSCs in bone marrow and the loss of differentiation capacity following in vitro expansion restrict their practical application. Effective improvement of MSC proliferation is necessary for the clinical application of MSC-based tissue engineering. The effects of estrogen supplements on proliferation and characterizations of human MSCs were investigated at the present study. Supplements of 17-ß estradiol (E2) significantly increase the proliferation of human MSCs in vitro. The dose range of E2 to significantly increase MSC proliferation differs in the gender of MSC donor. E2 supplementation in cell proliferation maintains characterizations of MSCs, including cell surface markers, and osteogenic and adipogenic differentiation capacities. These data indicate that estrogen treatment can play an important role in improving human MSCs' expansion in vitro, which will effectively facilitate MSCs' function in the practical application of tissue engineering and regeneration.

Steroid regulation of proliferation and osteogenic differentiation of bone marrow stromal cells: a gender difference.

Bone marrow mesenchymal stem cells (MSCs) are considered a potential cell source for stem cell-based bone tissue engineering. However, noticeable limitations of insufficient supply and reduction of differentiation potential impact the feasibility of their clinical application. This study investigated the in vitro function of steroids and gender differences on the proliferation and differentiation of rat MSCs. Bone marrow MSCs of age-matched rats were exposed to proliferation and osteogenic differentiation media supplements with various concentrations of 17beta-estradiol (E2) and dexamethasone. Cell proliferation was measured by MTS assay; osteogenic markers and steroid-associated growth factors and receptors were evaluated by ELISA and real-time PCR. The results revealed that supplements of E2 and dexamethasone increase MSC proliferation in a biphasic manner. The optimal dose and interaction of steroids required to improve MSC proliferation effectively varied depending on the gender of donors. Supplementation of E2 effectively improves osteogenic differentiation markers including ALP, osteocalcin and calcium levels for MSCs isolated from both male and female donors. The mRNA of TGF-beta1 and BMP-7 are also up-regulated. However, effective doses to maximally improve osteogenic potentials and growth factors for MSCs are different between male and female donors. The relationship between steroid receptors, osteogenic markers and cytokines are also varied by genders. The outcomes of the present study strongly indicate that steroids potentially function as an effective modulator to improve the capacity of MSCs in bone regeneration. It provides crucial information for improving and optimizing MSCs for future clinical application of bone regeneration.

Aspirin and indomethacin exhibit antiproliferative effects and induce apoptosis in T98G human glioblastoma cells.

The in vitro antiproliferative and apoptosis inducing properties of the nonsteroidal anti-inflammatory drugs (NSAIDs) like acetyl salicylic acid (aspirin) and indomethacin were investigated in T98G human glioblastoma cells to explore their potential role in the chemoprevention of human glioma. The biological effects induced by aspirin and indomethacin on T98G cells, in which the expression of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) were confirmed by RT-PCR and immunostaining, were investigated by studying cell proliferation and apoptosis assays. The antiproliferative effects occurred in a dose- and time-dependent manner on T98G cells by the treatment with 0.1 -2 mM aspirin and 25-100 microM indomethacin. Moreover, aspirin displayed the greatest growth inhibition within 24 h. Approximately 90% growth inhibition occurred following treatment either with 2 mM aspirin or 100 microM indomethacin by 72 h and induction of apoptosis was confirmed by DNA laddering and TUNEL assay. Our in vitro findings indicate that aspirin and indomethacin have an antiproliferative effect on T98G human glioblastoma cells at toxic concentrations.

PTEN expression is associated with prognosis for patients with advanced endometrial carcinoma undergoing postoperative chemotherapy.

The prognostic significance of PTEN expression in endometrial carcinoma has not been clear. We conducted the present study to clarify the relationship between PTEN expression and prognosis in advanced endometrial carcinoma. Of 784 patients with endometrial carcinoma who underwent primary treatment between 1985 and 2000 at 5 institutions, 98 pure endometrioid carcinomas with retroperitoneal lymph node metastasis were provided for our study. PTEN expression was determined by immunohistochemic staining. Negative or mixed PTEN staining was observed in 64 (65.3%) patients. The survival rate for PTEN-positive patients was significantly higher than that for PTEN-negative or -mixed patients. PTEN-staining status was not associated with patient age, International Federation of Gynecology and Obstetrics (FIGO) stage, myometrial invasion or histologic grade. Of the 98 patients, 87 received radiation therapy (n = 25) or chemotherapy (n = 62) after surgery. PTEN expression did not relate to survival for patients receiving radiation therapy. In contrast, the survival rate for PTEN-positive cases was significantly higher than that for PTEN-negative or -mixed cases when patients underwent chemotherapy (62.4% vs. 11.8%). Subsequent multivariate analysis revealed that PTEN staining was an independent prognostic factor for patients undergoing chemotherapy. PTEN-positive staining was a significant prognostic indicator of favorable survival for patients with advanced endometrial carcinoma who underwent postoperative chemotherapy.

Sensitivity to anticancer agents and resistance mechanisms in clear cell carcinoma of the ovary.

We conducted the present study to determine the chemoresistance mechanisms in clear cell carcinoma of the ovary (CCC). Five human CCC cell lines (HAC-2, RMG-I, RMG-II, KK, and KOC-7c) were used in this study. The sensitivity of the cells to the anticancer agents was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and we assessed drug sensitivity by calculating assay area under the curve (AUC) for each agent. The expression of multi-drug resistance genes (MDR-1, MRP-1, MRP-2) was detected by reverse transcription-polymerase chain reaction (RT-PCR). Glutathione (GSH) concentration was measured by an enzymatic assay. Topoisomerase (topo) I activity was assayed in terms of relaxation of supercoiled plasmid substrate DNA. The IC(50) to anticancer agents ranged widely. The assay AUC indicated that 3 of 5 cell lines (RMG-I, RMG-II, and KK) were sensitive to paclitaxel (PTX), 3 (HAC-2, RMG-I, and RMG-II) were sensitive to 7-ethyl-10-hydroxycamptothecin (SN-38), which is an active metabolite of camptothecin (CPT-11), and only one (HAC-2) was sensitive to cisplatin (CDDP). All cell lines were resistant to mitomycin-C (MMC) and etoposide (VP-16). The MRP-1 gene was detected in all cell lines. Only one cell line showed both MRP-2 and MDR-1 gene expression. Except for HAC-2 cells, expression of MRP genes was related to CDDP resistance, and MDR-1 gene expression was associated with PTX resistance. GSH concentrations increased after exposure to CDDP or MMC in all cell lines. There was a significant correlation between topo-I enzymatic activity and the response to SN-38. The present study revealed several resistance mechanisms in CCC and the results suggested that PTX and CPT-11 might be effective agents to treat CCC.