• Archives of Pharmacal Research
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• 제22권6호
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• pp.533-541
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• 1999

Many conventional anticancer drugs display relatively poor selectivity for neoplastic cells, in particular for solid tumors. Furthermore, expression or development of drug resistance, increased glutathione transferases as well as enhanced DNA repair decrease the efficacy of these drugs. Research efforts continue to overcome these problems by understanding these mechanisms and by developing more effective anticancer drugs. Cyclophosphamide is one of the most widely used alkylating anticancer agents. Because of its unique activation mechanism, numerous bioreversible prodrugs of phosphramide mustard, the active species of cyclophosphamide, have been investigated in an attempt to improve the therapeutic index. Solid tumors are particularly resistant to radiation and chemotherapy. There has been considerable interest in designing drugs selective for hypoxic environments prevalent in solid tumors. Much of the work had been centered on nitroheterocyclics that utilize nitroreductase enzyme systems for their activation. In this article, recent developments of anticancer prodrug design are described with a particular emphasis on exploitation of selective metabolic processes for their activation.

• Journal of Yeungnam Medical Science
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• 제6권2호
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• pp.195-205
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• 1989

암의 화학요법에 있어서 내성생성으로 인한 치료의 장애가 암 치료 실패의 중요 원인이 되며, 분 연구는 암세포의 항암제에 대한 내성 생성에 대한 특성을 연구 보고하였다. 사람의 위암 세포주 SNU-1에 대한 내성 유발을 위하여 세포배양액에 adriamycin(ADR) 농도를 $10^{-8}M$에서 $10^{-7}M$에 까지 적용시켜 내성세포주를 얻어 SUN-1/ADR로 나타내었으며 세포 성장은 SUN-1에서는 2일부터 6일까지 서서히 상승하였고 SNU-1/ADR은 $5{\times}10^3$celles/ml 농도 이상에서 상승을 보였다. 각 세포의 doubling 시간과 doubling 수를 비교하였으며 SNU-1은 doubling 시간이 평균 27.2 시간 doubling 수가 3.56번 이었으며, SNU-1/ADR은 52.2 시간 1.85번으로 내성세포가 더욱 성장이 왕성한 것을 관찰할 수 있다. MTT assay를 위하여 4일간의 성장으로 세포의 적절한 생존도를 관찰하였다. SNU-1과 내성세포주 SNU-1/ADR을 각각 항암제에 대한 약제 감수성 검사를 실시하였으며 약제농도 50%에서 생존도($IC_{50}$)를 비교하여 상관내성도(relative resistance : RR)을 측정 하였으며 vinblastine이 31.62이상으로 가장 높고, vincristine이 29.5, dactinomycin 21.37, epirubicin 17.78, daunorubicin 14.12였고, adriamycin 7.76이었으며 etoposide 4.46 이었다. 그 외의 약제 5-fluorouracil, cisplatin, cyclophosphamide, methotrexate, aclarubicin은 감수성이 낮았다. 위의 결과로 RR가 높은 약제들에 대해서는 multidrug resistance(복합내성)의 존재를 의미한다고 할 수 있으며 내성생성 SNU-1/ADR 세포주의 염색체의 검사에서 double minute chromosome(DMs)을 확인함으로서 내성 생성 세포를 확인 하였다.

• BMB Reports
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• 제49권4호
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• pp.238-243
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• 2016

The efficacy of anticancer drugs depends on a variety of signaling pathways, which can be positively or negatively regulated. In this study, we show that SETDB1 HMTase is down-regulated at the transcriptional level by several anticancer drugs, due to its inherent instability. Using RNA sequence analysis, we identified FosB as being regulated by SETDB1 during anticancer drug therapy. FosB expression was increased by treatment with doxorubicin, taxol and siSETDB1. Moreover, FosB was associated with an increased rate of proliferation. Combinatory transfection of siFosB and siSETDB1 was slightly increased compared to transfection of siFosB. Furthermore, FosB was regulated by multiple kinase pathways. ChIP analysis showed that SETDB1 and H3K9me3 interact with a specific region of the FosB promoter. These results suggest that SETDB1-mediated FosB expression is a common molecular phenomenon, and might be a novel pathway responsible for the increase in cell proliferation that frequently occurs during anticancer drug therapy.

• Asian Pacific Journal of Cancer Prevention
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• 제13권10호
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• pp.4855-4860
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• 2012

Since cancer is one of the leading causes of death worldwide, and there is an urgent need to find better treatment. In recent years remarkable progress has been made towards the understanding of proposed hallmarks of cancer development and treatment. Treatment modalities comprise radiation therapy, surgery, chemotherapy, immunotherapy and hormonal therapy. Currently, the use of chemotherapeutics remains the predominant option for clinical control. However, one of the major problems with successful cancer therapy using chemotherapeutics is that patients often do not respond or eventually develop resistance after initial treatment. This has led to the increased use of anticancer drugs developed from natural resources. The biodiversity of venoms and toxins makes them a unique source from which novel therapeutics may be developed. In this review, the anticancer potential of snake venom is discussed. Some of the included molecules are under clinical trial and may find application for anticancer drug development in the near future.

• Journal of Microbiology and Biotechnology
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• 제33권7호
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• pp.849-856
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• 2023

Short-chain fatty acids (SCFAs), such as butyrate, propionate, and acetate produced by the gut microbiota have been implicated in physiological responses (defense mechanisms, immune responses, and cell metabolism) in the human body. In several types of cancers, SCFAs, especially butyrate, suppress tumor growth and cancer cell metastasis via the regulation of the cell cycle, autophagy, cancer-related signaling pathways, and cancer cell metabolism. In addition, combination treatment with SCFAs and anticancer drugs exhibits synergistic effects, increasing anticancer treatment efficiency and attenuating anticancer drug resistance. Therefore, in this review, we point out the importance of SCFAs and the mechanisms underlying their effects in cancer treatment and suggest using SCFA-producing microbes and SCFAs to increase therapeutic efficacy in several types of cancers.

• Nutrition Research and Practice
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• 제18권1호
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• pp.62-77
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• 2024

BACKGROUND/OBJECTIVES: Colorectal cancer (CRC) is the third most common cancer worldwide with a high recurrence rate. Oxaliplatin (OXA) resistance is one of the major reasons hindering CRC therapy. β-Carotene (BC) is a provitamin A and is known to have antioxidant and anticancer effects. However, the combined effect of OXA and BC has not been investigated. Therefore, this study investigated the anticancer effects and mechanism of the combination of OXA and BC on CRC. MATERIALS/METHODS: In the present study, the effects of the combination of OXA and BC on cell viability, cell cycle arrest, and cancer stemness were investigated using HCT116, HT29, OXA-resistant cells, and human CRC organoids. RESULTS: The combination of OXA and BC enhanced apoptosis, G₂/M phase cell cycle arrest, and inhibited cancer cell survival in human CRC resistant cells and CRC organoids without toxicity in normal organoids. Cancer stem cell marker expression and self-replicating capacity were suppressed by combined treatment with OXA and BC. Moreover, this combined treatment upregulated apoptosis and the stem cell-related JAK/STAT signaling pathway. CONCLUSIONS: Our results suggest a novel potential role of BC in reducing resistance to OXA, thereby enhances the anticancer effects of OXA. This enhancement is achieved through the regulation of cell cycle, apoptosis, and stemness in CRC.

• 약학회지
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• 제52권1호
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• pp.67-72
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• 2008

The use of doxorubicin, which is one of the most effective anticancer agents, is often limited by occurrence of acquired resistance in tumor cells. GSH has been shown to be involved in the development of this drug resistance. Transcription factor Nrf2 governs the expression of GSH synthesizing glutamylcysteine ligase (GCL), as well as multiple phase 2 detoxifying enzymes. Here we show that Nrf2 is one of factors determining doxorubicin sensitivity. Nrf2-deficient fibroblasts (murine embryonic fibroblasts, MEF) were more susceptible to doxorubicin mediated cell death than wild-type cells. Doxorubicin treatment elevated levels of Nrf2-regulated genes including NAD(P)H: quinone oxidoreductase (Nqo1) and GCL in wild-type fibroblasts, while no induction was observed in Nrf2-deficient cells. Doxorubicin resistance in human ovarian SK-OV cells was reversed by treatment with L-buthionine-sulfoxamine (BSO), which is depleting intracellular GSH. Finally, transfection of SK-OV cells with Nrf2 siRNA resulted in exacerbated cytotoxicity following doxorubicin treatment compared to scrambled RNA control. These results indicate that the Nrf2 pathway, which plays a protective role in normal cells, can be a potential target to control cancer cell resistance to anticancer agents.

• Biomolecules & Therapeutics
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• 제22권3호
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• pp.167-175
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• 2014

Chemotherapy has long been considered as one of useful strategies for cancer treatment. It is primarily based on the apoptosis that can selectively kill cancer cells. However, cancer cells can progressively develop an acquired resistance to apoptotic cell death, rendering refractory to chemo- and radiotherapies. Although the mechanism by which cells attained resistance to drug remains to be clarified, it might be caused by either pumping out of them or interfering with apoptotic signal cascades in response to cancer drugs. In case that cancer cells are defective in some part of apoptotic machinery by repeated exposure to anticancer drugs, alternative cell death mechanistically distinct from apoptosis could be adopted to remove cancer cells refractory to apoptosis-inducing agents. This review will mainly deal with harnessing of necrotic cell death, specifically, programmed necrosis and practical uses. Here, we begin with various defects of apoptotic death machinery in cancer cells, and then provide new perspective on programmed necrosis as an alternative anticancer approach.

• 한국미생물·생명공학회지
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• 제32권1호
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• pp.47-51
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• 2004

암세포가 특정 항암제에 의해 내성을 획득하면 구조가 상이한 타 항암제에도 교차내성을 나타내는 이른바 암세포의 다약제 내성이 암 화학요법에 있어서 가장 심각한 문제가 되고 있다. 본 연구에서는 다약제 내성 암세포주인 CL02 세포를 이용하여 cellulose 용해성 점액세균인 Sorangium cellulosum의 60여종의 균주를 대상으로 다약재 내성 암세포에 유효한 항암물질을 탐색하는 과정에서, 균주 JW1006의 대사산물에서 강한 증식억제 활성을 발견하고 그 활성 본체로서 macrolide계 화합물인 Disorazoles $A_1$과 $A_2$를 분리하였다 Disorazoles $A_1$과 $A_2$는 인체기원의 암세포에 대해 모두 강한 세포독성($IC_{50}$ ＜0.04 ng/$m\ell$)을 나타낼 뿐 아니라 다약제내성 세포주인 CL02와 cisplatin내성 세포주인 CP70에 대해서 감수성 세포주와 동일한 활성을 나타내어 다약제 내성을 극복하는 우수한 활성 물질임을 확인하였다

• Natural Product Sciences
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• 제18권4호
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• pp.239-243
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• 2012

Mushrooms have a long history of use in traditional medicine, and hundreds of novel constituents in mushrooms with miraculous biological properties have been identified recently. Although diverse effects for medicinal use of mushrooms such as anticancer activity are proven, their reversal activities of drug resistance in cancer cells was rarely reported so far. In the search for novel medicinal use of mushrooms, we tested the multidrug resistance (MDR) reversal activities of diverse mushrooms collected from Korea. Among, the mushroom extracts tested, Cantharellus cibarius (M02) and Russula emetica (M12) revealed MDR reversal activities of paclitaxel in the P-glycoprotein (Pgp)-positive HCT15 and MES-SA/dX5 cancer cells, but not in the Pgp-negative A549 and MES-SA cancer cells. In addition, these mushrooms also enhanced the cytotoxicity of doxorubicin, another well-kwown Pgp-associated anticancer drug against MES-SA/DX5 cells, but not against MES-SA cells. Meanwhile, the cytotoxicity of cisplatin, a well-known Pgp-non-associated anticancer drug, was not affected by the mushrooms all the cells tested. From these results, we suspected that some ingredients of M02 and M12 have Pgp-associated MDR reversal activities.