• 생명과학회지
• /
• 제24권5호
• /
• pp.588-593
• /
• 2014

본 논문은 RLIP76 단백질이 암, 종양 혈관 신생 및 그 치료에 미치는 중요성을 보고함에 있다. 암의 연구에 있어서, 종양의 혈관 신생을 억제시키는 인자와 영향을 끼치는 인자를 밝혀내는 것은 암의 억제와 치료를 위한 분자 생물학적 기전에 중대한 영향을 미친다. 최근 연구에서, RLIP76 단백질이 혈관 신생에 영향을 끼치는 역할을 발견하였다. RLIP76 제거 마우스의 종양은 일반 종양과 비교하여 혈관의 크기가 작으며, 가늘고, 그 혈관의 수가 적고 길이가 짧은 것으로 보고되고 있다. 게다가, Matrigel plugs을 이용한 혈관 신생 실험에서, RLIP76이 제거된 마우스에서는 혈관 생성이 억제 되었으나, 일반 마우스에서는 혈관이 생성되었다. 또한, 혈관세포를 이용한 in vitro 실험에 있어서, proliferation, migration 및 cord formation 모두가 RLIP76에 의해서 조절되었다. 일반적으로 RLIP76은 대부분의 인간 조직과 종양에서 발현되며, 약의 저항 기전 연구에 이용되고 있기도 한다. 또한, 이RLIP76은 small GTPase R-Ras와 상호작용을 통하여 세포 spreading 및 migration에 관여하고 있다. 이러한 결과는 RLIP76와 암 연구의 중요성을 보고하고 있으며, 혈관 세포의 기능의 기전 및 종양의 혈관 신생을 위한 RLIP76 단백질의 중요성을 알리고 있고, RLIP76의 추가적인 연구를 통하여 종양의 혈관 신생의 기전을 밝히는 것이 필요함을 제안하는 바이다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권23호
• /
• pp.10439-10444
• /
• 2015

Many chemotherapeutic agents have been successfully used to treat hepatocellular carcinoma (HCC); however, the development of chemoresistance in liver cancer cells usually results in a relapse and worsening of prognosis. It has been demonstrated that DNA methylation and histone modification play crucial roles in chemotherapy resistance. Currently, extensive research has shown that there is another potential mechanism of gene expression control, which is mediated through the function of short noncoding RNAs, especially for microRNAs (miRNAs), but little is known about their roles in cancer cell drug resistance. In present study, by taking advantage of miRNA effects on the resistance of human hepatocellular carcinoma cells line to cisplatin, it has been demonstrated that miR-340 were significantly downregulated whereas Nrf2 was upregulated in HepG2/CDDP (cisplatin) cells, compared with parental HepG2 cells. Bioinformatics analysis and luciferase assays of Nrf2-3'-untranslated region-based reporter constructor indicated that Nrf2 was the direct target gene of miR-340, miR-340 mimics suppressing Nrf2-dependent antioxidant pathway and enhancing the sensitivity of HepG2/CDDP cells to cisplatin. Interestingly, transfection with miR-340 mimics combined with miR-340 inhibitors reactivated the Nrf2 related pathway and restored the resistance of HepG2/CDDP cells to CDDP. Collectively, the results first suggested that lower expression of miR-340 is involved in the development of CDDP resistance in hepatocellular carcinoma cell line, at least partly due to regulating Nrf2-dependent antioxidant pathway.

• 생명과학회지
• /
• 제30권5호
• /
• pp.460-467
• /
• 2020

간암은 전 세계적으로 가장 높게 진단되는 암 중 하나이며, 방사선 및 화학 요법이 일반적으로 사용되는 치료법이지만 다양한 부작용은 치료 효과를 크게 제한한다. 따라서 전통 의학에서 사용되어 온 처방법은 이를 극복할 수 있는 대안이 될 수 있다. 본 연구에서는 동의보감에 기술되어 있는 3가지 한약 처방전(비기환, 대칠기탕 및 목향빈랑환)을 선택하여 인체 간암세포에 대한 항암 효과를 평가하였다. 간암세포에서 3가지 처방전의 에탄올 추출물의 세포 독성을 조사하기 위한 MTT 분석 결과, 비기환 추출물은 대칠기탕 및 목향빈랑환에 비하여 세포 생존력을 현저하게 억제하였다. 그리고, flow cytometry 분석의 결과에서 3가지 처방전 추출물에 의한 간암세포의 증식 억제가 apoptosis 및 autophagy 유도와 관련이 있었다. 특히, 비기환 추출물은 미토콘드리아의 기능을 크게 손상시켰으며 다른 두 처방전과 비교하여 mitophagy 유발 가능성을 보여주었다. 아울러 비기환 추출물은 LC3의 발현을 현저하게 증가시켰으며, 이는 Bcl-2의 발현 감소를 동반하는 반면, Bax의 발현에 영향을 미치지 않았다. PINK1의 발현 또한 비기환 추출물이 처리된 세포에서 매우 증가하였다. 나아가, autophagy 억제제는 3가지 처방전 추출물 처리에 의한 세포 생존율 감소와 apoptosis 유도를 억제하였으며, 이러한 결과는 이들 처방전 추출물 처리에 의한 autophagy가 apoptosis 개시에 관여하고 있음을 보여주는 것이다. 결론적으로, 본 연구 결과는 비기환 추출물이 3가지 처방전 중에서 가장 높은 항암 활성을 보였으며, 비기환 추출물은 autophagy 유도제로서 간암세포의 증식을 억제함을 의미한다.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권12호
• /
• pp.6191-6196
• /
• 2012

Aims and Background: Traditional chemotherapy strategies for human leukemia commonly use drugs based on cytotoxicity to eradicate cancer cells. One predicament is that substantial damage to normal tissues is likely to occur in the course of standard treatments. Obviously, it is urgent to explore therapies that can effectively eliminate malignant cells without affecting normal cells. Our previous studies indicated that ginsenoside $Rg_1$ ($Rg_1$), a major active pharmacological ingredient of ginseng, could delay normal hematopoietic stem cell senescence. However, whether $Rg_1$ can induce cancer cell senescence is still unclear. Methods: In the current study, human leukemia K562 cells were subjected to $Rg_1$ exposure. The optimal drug concentration and duration with K562 cells was obtained by MTT colorimetric test. Effects of $Rg_1$ on cell cycle were analyzed using flow cytometry and by SA-${\beta}$-Gal staining. Colony-forming ability was measured by colony-assay. Telomere lengths were assessed by Southern blotting and expression of senescence-associated proteins P21, P16 and RB by Western blotting. Ultrastructural morphology changes were observed by transmission electron microscopy. Results: K562 cells demonstrated a maximum proliferation inhibition rate with an $Rg_1$ concentration of $20{\mu}\;mol{\cdot}L^{-1}$ for 48h, the cells exhibiting dramatic morphological alterations including an enlarged and flat cellular morphology, larger mitochondria and increased number of lysosomes. Senescence associated-${\beta}$-galactosidase (SA-${\beta}$-Gal) activity was increased. K562 cells also had decreased ability for colony formation, and shortened telomere length as well as reduction of proliferating potential and arrestin $G_2$/M phase after $Rg_1$ interaction. The senescence associated proteins P21, P16 and RB were significantly up-regulated. Conclusion: Ginsenoside $Rg_1$ can induce a state of senescence in human leukemia K562 cells, which is associated with p21-Rb and p16-Rb pathways.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권7호
• /
• pp.4301-4306
• /
• 2013

Aim: Apoptosis has been considered as a fundamental component in cancer pathogenesis, and related genetic factors might play an important role in gastric cardiac adenocarcinoma (GCA) genesis. Methods: We conducted a hospital based case.control study to evaluate the genetic effects of functional single nucleotide polymorphisms (SNPs): BCL2 rs17757541 C>G, BCL2 rs12454712 T>C, FAS rs2234767 G>A, FASL/FASLG rs763110 C>T, ERBB2 rs1136201 A>G and VEGFR2/KDR rs11941492 C>T on the development of GCA. A total of 243 GCA cases and 476 controls were recruited for the study and genotypes were determined using a custom-by-design 48-Plex SNPscan$^{TM}$ Kit. Results: The BCL2 rs17757541 C>G polymorphism was associated with increased risk of GCA. However, there was no significant associations with the other five SNPs. Stratified analyses indicated a significantly increased risk of GCA associated with the BCL2 rs17757541 C>G polymorphism among males, older patients and those with a history of smoking or drinking. Conclusion: These findings indicated that the functional polymorphism BCL2 rs17757541 C>G might contribute to GCA susceptibility. However, our results were limited by small sample size. Future larger studies are required to confirm our current findings.

• Asian Pacific Journal of Cancer Prevention
• /
• 제17권9호
• /
• pp.4259-4265
• /
• 2016

Background: Colorectal malignancies with high microsatellite instability (MSI-H), either hereditary (Lynch syndrome) or sporadic, demonstrate better prognosis and altered response to 5FU chemotherapy. It is now recommended to perform MSI testing for all new cases of colorectal cancer regardless of being categorized as hereditary or sporadic. For MSI detection, immunohistochemistry or PCR-based protocols using a cohort of various sets of STR markers are recommended. Here we aimed to evaluate a simplified protocol using just a single STR marker, MT1XT20 mononucleotide repeat, for detection of MSI in Lynch syndrome patients. A Promega five-marker MSI testing panel and immunohistochemistry (IHC) were used as the gold standard in conjunction with MT1XT20. Materials and Methods: Colorectal patients with a positive history of familial cancers were selected by evaluating medical records. Based on Amsterdam II criteria for Lynch syndrome 20 families were short listed. DNA was extracted from formalin fixed paraffin embedded tumour and adjacent normal tissues resected from the index case in each family. Extracted DNA was subjected to MT1XT20 mononucleotide marker analysis and assessment with a commercially available five marker MSI testing kit (Promega, USA). IHC also was performed on tissue sections and the results were compared with PCR based data. Results: Eight (40%), seven (35%) and five (25%) cases were MSI positive using with the Promega kit, IHC and MT1XT20, respectively. Among the markers included in Promega kit, BAT26 marker showed instability in all 8 samples. NR24 and NR21 markers showed instability in 7 (87.5%), and BAT25 and MONO 27 in 6 (75%) and 5 (62.5%). Conclusions: Although MT1XT20 was earlier reported as a valid standalone marker for MSI testing in CRC patients, we could not verify this in our Iranian patients. Instead BAT26 among the markers included in Promega MSI testing kit showed instability in all 8 MSI-H CRC samples. Therefore, it seems BAT26 could act well as a single marker for MSI testing in Iranian CRC patients.

• Journal of Gastric Cancer
• /
• 제3권4호
• /
• pp.191-194
• /
• 2003

Purpose: Neuroendocrine carcinomas of the stomach account for only about $0.3\%$ of all gastric tumors. The prognosis of this disease is very poor compared with the common type of gastric adenocarcinoma. The purpose of this retrospective study was to review the clinicopathologic features of 18 cases of this unusual gastric tumor and to establish a treatment strategy for this tumor. Materials and Methods: Excluding 2 cases of non-curative resection and 1 case of operative mortality, 18 cases of typical neuroendocrine carcinoma who had curative resection from January 1991 to December 2000 at Asan Medical Center were analyzed; 6841 gastric cancer patient were treated surgically during the same period. Results: The mean age at the time of diagnosis was 58.6 years (range: $35\∼75$ yr). Sixteen patients were male, and two were female. Eleven tumors ($61.1\%$) developed in the lower part of the stomach, three ($16.7\%$) in the middle part, and three ($16.7\%$) in the upper part. One tumor involved the entire stomach. Eight cases ($44.4\%$) were Borrmann type 2, and six case ($33.3\%$) were Borrmann type 3. The mean tumor size was 6.94 cm (range: $0.6\∼15$ cm). Nine cases ($50\%$) showed recurrence of the disease, and eight of them died within 20 months. Of the nine recurred cases, 7 cases ($77.8\%$) showed liver metastasis. The mean disease-free interval was 6.8 months (range: $2.5\∼11$ months) after surgical resection, and the mean survival was 17.9 months (range: $8\∼40$ months) for recurrence cases. One patient with liver metastasis was treated with a liver-wedge resection just after diagnosis and was still alive for 37.5 months postoperatively. There were 9 deaths after the median follow- up period of 40 months (range: $8\∼72$ months). Conclusion: Gastric neuroendocrine carcinomas frequently recur at the liver, even in early stage cancer, and have a poor prognosis. We experienced a case of successful control of hepatic metastasis by surgical resection and a case of a small cell carcinoma which was successfully controlled with systemic chemotherapy.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권7호
• /
• pp.3123-3128
• /
• 2014

The liver is normally the major site of glucose metabolism in intact organisms and the most important target organ for the action of insulin. It has been widely accepted that insulin resistance (IR) is closely associated with postoperative recurrence of hepatocellular carcinoma (HCC). However, the relationship between IR and drug resistance in liver cancer cells is unclear. In the present study, IR was induced in HepG2 cells via incubation with a high concentration of insulin. Once the insulin-resistant cell line was established, the stability of HepG2/IR cells was further tested via incubation in insulin-free medium for another 72h. Afterwards, the biological effects of insulin resistance on adhesion, migration, invasion and sensitivity to cis-platinum (DDP) of cells were determined. The results indicated that glucose consumption was reduced in insulin-resistant cells. In addition, the expression of the insulin receptor and glucose transportor-2 was downregulated. Furthermore, HepG2/IR cells displayed markedly enhanced adhesion, migration, and invasion. Most importantly, these cells exhibited a lower sensitivity to DDP. By contrast, HepG2/IR cells exhibited decreased adhesion and invasion after treatment with the insulin sensitizer pioglitazone hydrochloride. The results suggest that IR is closely related to drug resistance as well as adhesion, migration, and invasion in HepG2 cells. These findings may help explain the clinical observation of limited efficacy for chemotherapy on a background of IR, which promotes the invasion and migration of cancer cells.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권8호
• /
• pp.3581-3586
• /
• 2014

Aim: To investigate the effects of tetramethypyrazine (TMP) on proliferation and apoptosis of the human gastric carcinoma cell line 7901 and its possible mechanism of action. Methods: The viability of TMP-treated 7901 cells was measured with a 3-(4, 5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT) and cell apoptosis was analyzed by flow cytometry. The distribution of cells in different phases of cell cycle after exposure of TMPs was analyzed with flow cytometry. To investigate the molecular mechanisms of TMP-mediated apoptosis, the expression of NF-${\kappa}Bp65$, cyclinD1 and p16 in SGC-7901 cells was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. Results: TMP inhibited the proliferation of human gastric carcinoma cell line 7901 in dose and time dependent manners. Cell growth was suppressed by TMP at different concentrations (0.25, 0.5, 1.0, 2.0 mg/ml), the inhibition rate is 0.46%, 4.36%, 14.8%, 76.1% (48h) and 15.5%, 18.5%, 41.2%, 89.8% (72h) respectively. When the concentration of TMPs was 2.0mg/ml, G1-phase arrest in the SGC-7901 cells was significant based on the data for cell cycle distribution. RT-PCR demonstrated that NF-${\kappa}Bp65$ and cyclin D1 mRNA expression was significantly down-regulated in 7901 cells treated with 2.0 mg/ml TMP for 72h (p<0.05), while the p16 mRNA level was up-regulated (p<0.05). The protein expression of NF-${\kappa}Bp65$ and cyclin D1 decreased gradually with the increase in TMP concentration, compared with control cells (p<0.05), while expression of protein p16 was up-regulated (p<0.01). Conclusion: TMP exhibits significant anti-proliferative and pro-apoptotic effects on the human gastric carcinoma cell line SGC-7901. NF-${\kappa}Bp65$, cyclinD1 and p16 may also play important roles in the regulation mechanisms.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권8호
• /
• pp.3651-3657
• /
• 2014

Hepatocellular carcinoma (HCC) has a relatively higher incidence in many countries of Asia. Globally, HCC has a high fatality rate and short survival. Epirubicin, a doxorubicin analogue, may be administered alone or in combination with other agents to treat primary liver cancer and metastatic diseases. However, the toxic effects of epirubicin to normal tissues and cells have been one of the major obstacles to successful cancer chemotherapy. Here, we investigated the effects of epirubicin in combination with kappa-selenocarrageenan on mice with H22 implanted tumors and HepG-2 cell proliferation, immune organ index, morphology, cell cycle and related protein expressions in vivo and in vitro with sequential drug exposure. The inhibitory rate of tumor growth in vivo was calculated. Drug sensitivity was measured by MTT assay, and the King's principle was used to evaluate the interaction of drug combination. Morphological changes were observed by fluorescent microscopy. Cell cycle changes were analyzed by flow cytometry. Expression of cyclin A, Cdc25A and Cdk2 were detected by Western blotting. In vivo results demonstrated that the inhibitory rate of EPI combined with KSC was higher than that of KSC or EPI alone, and the Q value indicated an additive effect. In addition, KSC could significantly raise the thymus and spleen indices of mice with H22 implanted tumors. In the drug sensitivity assay in vitro, exposure to KSC and EPI simultaneously was more effective than exposure sequentially in HepG-2 cells, while exposure to KSC prior to EPI was more effective than exposure to EPI prior to KSC. Q values showed an additive effect in the simultaneous group and antagonistic effects in the sequential groups. Morphological analysis showed similar results to the drug sensitivity assay. Cell cycle analysis revealed that exposure to KSC or EPI alone arrested the cells in S phase in HepG-2 cells, exposure to KSC and EPI simultaneously caused accumulation in the S phase, an effect caused by either KSC or EPI. Expression of cyclin A, Cdc25A and Cdk2 protein was down-regulated following exposure to KSC and EPI alone or in combination, exposure to KSC and EPI simultaneously resulting in the lowest values. Taken together, our findings suggest that KSC in combination with EPI might have potential as a new therapeutic regimen against HCC.