ABT-737 Synergizes with Cisplatin Bypassing Aberration of Apoptotic Pathway in Non-small Cell Lung Cancer

Kim, Eun Young,Jung, Ji Ye,Kim, Arum,Chang, Yoon Soo,Kim, Se Kyu Neoplasia Press 2017 Neoplasia Vol.19 No.4

<P>A subset of non-small cell lung cancer (NSCLC), which does not have a druggable driver mutation, is treated with platinum-based cytotoxic chemotherapy, but it develops resistance triggered by DNA damage responses. Here, we investigated the effect of activation of STAT3 by cisplatin on anti-apoptotic proteins and the effectiveness of a co-treatment with cisplatin and a BH3 mimetic, ABT-737. We analyzed the relationship between cisplatin and STAT3 pathway and effect of ABT-737, when combined with cisplatin in NSCLC cells and K-ras mutant mouse models. The synergism of this combination was evaluated by the Chou-Talalay Combination Index method. In <I>vivo</I> activity was evaluated by micro-CT. In NSCLC cells, there was a time and dose-dependent phosphorylation of SRC-JAK2-STAT3 by cisplatin, followed by increased expression of anti-apoptotic molecules. When the expression of the BCL-2 protein family members was evaluated in clinical samples, BCL-xL was most frequently overexpressed. Dominant negative STAT3 suppressed their expression, suggesting that STAT3 mediates cisplatin mediated overexpression of the anti-apoptotic molecules. ABT-737 displaced BCL-xL from mitochondria and induced oligomerization of BAK. ABT-737 itself showed cytotoxic effects and a combination of ABT-737 with cisplatin showed strong synergistic cytotoxicity. In a murine lung cancer model, co-treatment with ABT-737 and cisplatin induced significant tumor regression. These findings reveal a synergistic cytotoxic and anti-tumor activity of ABT-737 and cisplatin co-treatment in preclinical models, and suggest that clinical trials using this strategy may be beneficial in advanced NSCLC.</P>

Clinical Significance of <i>IGFBP-3</i> Methylation in Patients with Early Stage Gastric Cancer ¹

Kim, Seung Tae,Jang, Hye-Lim,Lee, Jeeyun,Park, Se Hoon,Park, Young Suk,Lim, Ho Yeong,Choi, Min Gew,Bae, Jae Moon,Sohn, Tae Sung,Noh, Jae Hyung,Kim, Sung,Kim, Kyoung-Mee,Kang, Won Ki,Park, Joon Oh Neoplasia Press 2015 Translational oncology Vol.8 No.4

<P><I>BACKGROUND: IGFBP-3</I> is a multifunctional protein that inhibits growth and induces apoptosis of cancer cells. Hypermethylation of the promoter represses expression of the <I>IGFBP-3</I> gene. We undertook this study to assess the impact of <I>IGFBP-3</I> methylation on survival of early stage gastric cancer patients. <I>METHODS:</I> Of the 482 tissue samples from gastric cancer patients who underwent curative surgery, <I>IGFBP-3</I> methylation was tested in 138 patients with stage IB/II gastric cancer. We also analyzed IGFBP-3 methylation in 26 gastric cancer cell lines. <I>IGFBP-3</I> methylation was evaluated by methylation-specific polymerase chain reaction (MethyLight). Statistical analyses, all two-sided, were performed to investigate the prognostic effects of methylation status of the <I>IGFBP-3</I> promoter on various clinical parameters. <I>RESULTS:</I> Hypermethylation of <I>IGFBP-3</I> was observed in 26 (19%) of the 138 stage IB/II gastric cancer patients. Clinicopathological factors such as age, Lauren classification, sex, tumor infiltration, lymph node metastasis, and histologic grade did not show a statistically significant association with the methylation status of the <I>IGFBP-3</I> promoter. Patients with a hypermethylated <I>IGFBP-3</I> promoter had similar 8-year disease-free survival compared with those without a hypermethylated <I>IGFBP-3</I> promoter (73% vs 75%, <I>P</I> = .78). In subgroup analyses, females, but not males, seemed to have poorer prognosis for DFS and OS in the subset of patients with <I>IGFBP-3</I> methylation as compared with those without <I>IGFBP-3</I> methylation (8-year DFS: 55.6% vs 71.6%, <I>P</I> = .3694 and 8-year overall survival: 55.6% vs 68.4%, <I>P</I> = .491, respectively) even with no statistical significance. <I>CONCLUSIONS:</I> The status of <I>IGFBP-3</I> methylation as measured by methylation-specific polymerase chain reaction proposed the modest role for predicting survival in specific subgroups of patients with early-stage gastric cancer who undergo curative surgery. However, this needs further investigation.</P>

Kaempferol Suppresses Transforming Growth Factor-β1–Induced Epithelial-to-Mesenchymal Transition and Migration of A549 Lung Cancer Cells by Inhibiting Akt1-Mediated Phosphorylation of Smad3 at Threonine-179 ¹

Jo, Eunji,Park, Seong Ji,Choi, Yu Sun,Jeon, Woo-Kwang,Kim, Byung-Chul Neoplasia Press 2015 Neoplasia Vol.17 No.7

<P>Kaempferol, a natural dietary flavonoid, is well known to possess chemopreventive and therapeutic anticancer efficacy; however, its antimetastatic effects have not been mechanistically studied so far in any cancer model. This study was aimed to investigate the inhibitory effect and accompanying mechanisms of kaempferol on epithelial-to-mesenchymal transition (EMT) and cell migration induced by transforming growth factor-β1 (TGF-β1). In human A549 non–small lung cancer cells, kaempferol strongly blocked the enhancement of cell migration by TGF-β1–induced EMT through recovering the loss of E-cadherin and suppressing the induction of mesenchymal markers as well as the upregulation of TGF-β1–mediated matrix metalloproteinase-2 activity. Interestingly, kaempferol reversed TGF-β1–mediated Snail induction and E-cadherin repression by weakening Smad3 binding to the Snail promoter without affecting its C-terminus phosphorylation, complex formation with Smad4, and nuclear translocation under TGF-β1 stimulation. Mechanism study revealed that the phosphorylation of Smad3 linker region induced by TGF-β1 was required for the induction of EMT and cell migration, and selective downregulation of the phosphorylation of Smad3 at Thr179 residue (not Ser204, Ser208, and Ser213) in the linker region was responsible for the inhibition by kaempferol of TGF-β1–induced EMT and cell migration. Furthermore, Akt1 was required for TGF-β1–mediated induction of EMT and cell migration and directly phosphorylated Smad3 at Thr179, and kaempferol completely abolished TGF-β1–induced Akt1 phosphorylation. In summary, kaempferol blocks TGF-β1–induced EMT and migration of lung cancer cells by inhibiting Akt1-mediated phosphorylation of Smad3 at Thr179 residue, providing the first evidence of a molecular mechanism for the anticancer effect of kaempferol.</P>

Predominant Activation of JAK/STAT3 Pathway by Interleukin-6 Is Implicated in Hepatocarcinogenesis ¹ ²

Jung, In Hye,Choi, Jeffrey Hyun-Kyu,Chung, Yong-Yoon,Lim, Ga-Lam,Park, Young-Nyun,Park, Seung Woo Neoplasia Press 2015 Neoplasia Vol.17 No.7

<P>Chronic inflammation is an important process leading to tumorigenesis. Therefore, targeting and controlling inflammation can be a promising cancer therapy. Inflammation is often caused by a variety of inflammatory cytokine such as the interleukin (IL)-6, a pleiotrophic cytokine known to be involved in the tumorigenesis. In this study, an <I>in vivo</I> hepatic tumorigenesis model of zebrafish was generated to demonstrate a direct consequence of the human IL6 expression causing hepatocarcinogenesis. To do this, an elevated expression of the hIL6 gene was established to specifically target the zebrafish hepatocytes by transgenesis. Interestingly, the elevated hIL6 expression caused the chronic inflammation which results in a massive infiltration of inflammatory cells. This eventually resulted in the generation of various dysplastic lesions such as clear cell, small cell, and large cell changes, and also eosinophilic and basophilic foci of hepatocellular alteration. Hepatocellular carcinoma was then developed in the transgenic zebrafish. Molecular characterization revealed upregulation of the downstream components involved in the IL6-mediated signaling pathways, especially PI3K/Akt and JAK/STAT3 pathways. Further investigation indicated that PI3K was the most reactive to the infiltrated inflammatory cells and dysplasia with large cell change, whereas STAT3 was heavily activated in the region with dysplastic foci, suggesting that the JAK/STAT3 pathway was mainly implicated in the hepatic tumorigenesis in the current model. Our present study provides an <I>in vivo</I> evidence of the relationship between chronic inflammation and tumorigenesis and reinforces the pivotal role of IL6 in the inflammation-associated hepatocarcinogenesis.</P>

Molecular Subgroup Analysis of Clinical Outcomes in a Phase 3 Study of Gemcitabine and Oxaliplatin with or without Erlotinib in Advanced Biliary Tract Cancer

Kim, Seung Tae,Jang, Kee-Taek,Lee, Jeeyun,Jang, Heung-Moon,Choi, Hye-Jin,Jang, Hye-Lim,Park, Se Hoon,Park, Young Suk,Lim, Ho Yeong,Kang, Won Ki,Park, Joon Oh Neoplasia Press 2015 Translational oncology Vol.8 No.1

<P><I>BACKGROUND:</I> We previously reported that the addition of erlotinib to gemcitabine and oxaliplatin (GEMOX) resulted in greater antitumor activity and might be a treatment option for patients with biliary tract cancers (BTCs). Molecular subgroup analysis of treatment outcomes in patients who had specimens available for analysis was undertaken. <I>METHODS: Epidermal growth factor receptor</I> (<I>EGFR</I>), <I>KRAS</I>, and <I>PIK3CA</I> mutations were evaluated using peptide nucleic acid–locked nucleic acid polymerase chain reaction clamp reactions. Survival and response rates (RRs) were analyzed according to the mutational status. Sixty-four patients (48.1%) were available for mutational analysis in the chemotherapy alone group and 61 (45.1%) in the chemotherapy plus erlotinib group. <I>RESULTS:</I> 1.6% (2/116) harbored an EGFR mutation (2 patients; exon 20), 9.6% (12/121) harbored a KRAS mutation (12 patients; exon 2), and 9.6% (12/118) harbored a PIK3CA mutation (10 patients, exon 9 and 2 patients, exon 20). The addition of erlotinib to GEMOX in patients with KRAS wild-type disease (<I>n</I> = 109) resulted in significant improvements in overall response compared with GEMOX alone (30.2% <I>vs</I> 12.5%, <I>P</I> = .024). In 95 patients with both wild-type KRAS and PIK3CA, there was evidence of a benefit associated with the addition of erlotinib to GEMOX with respect to RR as compared with GEMOX alone (<I>P</I> = .04). <I>CONCLUSION:</I> This study demonstrates that KRAS mutational status might be considered a predictive biomarker for the response to erlotinib in BTCs. Additionally, the mutation status of PIK3CA may be a determinant for adding erlotinib to chemotherapy in KRAS wild-type BTCs.</P>

TSH Signaling Overcomes B-RafV600E–Induced Senescence in Papillary Thyroid Carcinogenesis through Regulation of DUSP6 ¹ ²

Kim, Young Hwa,Choi, Yong Won,Han, Jae Ho,Lee, Jeonghun,Soh, Euy Young,Park, So Hyun,Kim, Jang-Hee,Park, Tae Jun Neoplasia Press 2014 Neoplasia Vol.16 No.12

<P>B-RafV600E oncogene mutation occurs most commonly in papillary thyroid carcinoma (PTC) and is associated with tumor initiation. However, a genetic modification by B-RafV600E in thyrocytes results in oncogene-induced senescence (OIS). In the present study, we explored the factors involved in the senescence overcome program in PTC. First of all, we observed down-regulation of p-extracellular signal-regulated kinases 1/2 and up-regulation of dual specific phosphatase 6 (DUSP6) in the PTC with B-RafV600E mutation. DUSP6 overexpression <I>in vitro</I> induced extracellular signal-regulated kinases 1/2 dephosphorylation and inhibited B-RafV600E–induced senescence in thyrocytes. Although DUSP6 protein was degraded by B-RafV600E–induced reactive oxygen species (ROS), thyroid-stimulating hormone (TSH) stabilized DUSP6 protein by increasing Mn superoxide dismutase expression and inhibited B-RafV600E–induced senescence. Although serum TSH was not increased, its receptor was markedly upregulated in PTC with B-RafV600E. Furthermore, TSH together with DUSP6 reactivated Ras signaling, resulted in activation of Ras/AKT/glycogen synthase kinase 3β, and stabilized c-Myc protein by inhibiting its degradation. These observations led us to conclude that increased TSH signaling overcomes OIS and is essential for B-RafV600E–induced papillary thyroid carcinogenesis.</P>

Antiangiogenic Therapy with Human Apolipoprotein(a) Kringle V and Paclitaxel in a Human Ovarian Cancer Mouse Model ¹ ²

Yu, Hyun-Kyung,Lee, Ho-Jeong,Yun, Seok-Joong,Lee, Sun-Joo,Langley, Robert R.,Yoon, Yeup,Yi, Lee S.H.,Bae, Duk-Soo,Kim, Jang-Seong,Kim, Sun Jin Neoplasia Press 2014 Translational oncology Vol.7 No.3

<P><I>INTRODUCTION:</I> The present study compared the effect of combination therapy using human apolipoprotein(a) kringle V (rhLK8) to conventional chemotherapy with paclitaxel for human ovarian carcinoma producing high or low levels of vascular endothelial growth factor (VEGF). <I>MATERIALS AND METHODS:</I> Human ovarian carcinoma cells producing high (SKOV3ip1) or low (HeyA8) levels of VEGF were implanted into the peritoneal cavity of female nude mice. Seven days later, mice were randomized into four groups: control (vehicle), paclitaxel [5 mg/kg, weekly intraperitoneal (i.p.) injection], rhLK8 (50 mg/kg, daily i.p. injection), or the combination of paclitaxel and rhLK8. Mice were treated for 4 weeks and examined by necropsy. <I>RESULTS:</I> In mice implanted with SKOV3ip1 cells, rhLK8 treatment had no significant effect on tumor incidence or the volume of ascites but induced a significant decrease in tumor weight compared with control mice. Paclitaxel significantly reduced tumor weight and ascites volume, and combination treatment with paclitaxel and rhLK8 had an additive therapeutic effect. Similarly, in HeyA8 mice, the effect of combination treatment on tumor weight and tumor incidence was statistically significantly greater than that of paclitaxel or rhLK8 alone. Immunohistochemical analysis showed a significant decrease in microvessel density and a marked increase of apoptosis in tumor and tumor-associated endothelial cells in response to combination treatment with paclitaxel and rhLK8. <I>CONCLUSION:</I> Collectively, these results suggest that antiangiogenic therapy with rhLK8 in combination with taxane-based conventional chemotherapy could be effective for the treatment of ovarian carcinomas, regardless of VEGF status.</P>

Elevated Estrogen Receptor-α in VHL-Deficient Condition Induces Microtubule Organizing Center Amplification via Disruption of BRCA1/Rad51 Interaction

Jung, Youn-Sang,Chun, Ho-Young,Yoon, Min-Ho,Park, Bum-Joon Neoplasia Press 2014 Neoplasia Vol.16 No.12

<P>Since loss of VHL is frequently detected early phase genetic event in human renal cell carcinoma, pVHL is assumed to be indispensable for suppression of tumor initiation step. However, induction of HIF-1α, target of pVHL E3 ligase, is more adequate to angiogenesis step after tumor mass formation. Concerning this, it has been reported that pVHL is involved in centrosome location during metaphase and regulates ER-α signaling. Here, we provide the evidences that pVHL-mediated ER-α suppression is critical for microtubule organizing center (MTOC) maintaining and elevated ER-α promotes MTOC amplification through disruption of BRCA1-Rad51 interaction. In fact, numerous MTOC in VHL- or BRCA1-deficient cells are reduced by Fulvestrant, inhibitor of ER-α expression as well as antagonist. In addition, we reveal that activation of ER signaling can increase γ-tubulin, core factor of TuRC and render the resistance to Taxol. Thus, Fulvestrant but not Tamoxifen, antagonist against ER-α, can restore the Taxol sensitivity in VHL- or BRCA1-deficient cells. Our results suggest that pVHL-mediated ER-α suppression is important for regulation of MTOC as well as drug resistance.</P>

Reciprocal Interaction between Carcinoma-Associated Fibroblasts and Squamous Carcinoma Cells through Interleukin-1α Induces Cancer Progression ¹ ²

Bae, Jung Yoon,Kim, Eun Kyoung,Yang, Dong Hyun,Zhang, Xianglan,Park, Young-Jin,Lee, Doo Young,Che, Chung Min,Kim, Jin Neoplasia Press 2014 Neoplasia Vol.16 No.11

<P>Crosstalk between cancer cells and carcinoma-associated fibroblasts (CAFs) has earned recognition as an interaction that plays a pivotal role in carcinogenesis. Thus, we attempted to clarify whether increase in the level of CAFs promotes cancer progression by proportionally enhancing the interaction between cancer cells and CAFs. We first analyzed clinical correlation between the levels of fibroblasts and cancer progression and found that the level of CAFs made a noticeable difference on the prognosis of patients with oral squamous cell carcinoma (OSCC). <I>In vivo</I> animal study also demonstrated that tumor volume depended on the dose of CAFs that was co-injected with OSCC cells. The same tendency was observed in an <I>in vitro</I> study. We also found that interleukin-1α (IL-1α) secreted from OSCC cells had dual effects on CAFs: IL-1α not only promoted the proliferation of CAFs but also upregulated the secretion of cytokines in CAFs such as CCL7, CXCL1, and IL-8. The induction activity of cytokine secretion by IL-1α surpassed that of proliferation in OSCC cells. In summary, we unraveled an important interactive mechanism of carcinogenesis: IL-1α released from carcinoma stimulates the proliferation of CAFs and the simultaneous increase in cytokine secretion from CAFs promotes cancer progression in human OSCC. On the basis of these findings, we propose that the level of CAFs is eligible for being selected as a prognostic factor that will be useful in routine diagnosis. We also propose that blockage of reciprocal interaction between cancer cells and CAFs will provide an insight for developing novel chemotherapeutic strategy.</P>

Overcoming Chemoresistance of Pediatric Ependymoma by Inhibition of STAT3 Signaling

Phi, Ji Hoon,Choi, Seung-Ah,Kim, Seung-Ki,Wang, Kyu-Chang,Lee, Ji Yeoun,Kim, Dong Gyu Neoplasia Press 2015 Translational oncology Vol.8 No.5

<P>The long-term clinical outcome of pediatric intracranial epepdymoma is poor with a high rate of recurrence. One of the main reasons for this poor outcome is the tumor’s inherent resistance to chemotherapy. Signal transducer and activator of transcription 3 (STAT3) is overactive in many human cancers, and inhibition of STAT3 signaling is an emerging area of interest in oncology. In this study, the possibility of STAT3 inhibition as a treatment was investigated in pediatric intracranial ependymoma tissues and cell lines. STAT3 activation status was checked in ependymoma tissues. The responses to conventional chemotherapeutic agents and a STAT3 inhibitor WP1066 in primarily cultured ependymoma cells were measured by cell viability assay. Apoptosis assays were conducted to reveal the cytotoxic mechanism of applied agents. Knockdown of STAT3 was tried to confirm the effects of STAT3 inhibition in ependymoma cells. High levels of phospho-STAT3 (p-STAT3) expression were observed in ependymoma tissue, especially in the anaplastic histology group. There was no cytotoxic effect of cisplatin, ifosfamide, and etoposide. Both brain tumor-initiating cells (BTICs) and bulk tumor cells (BCs) showed considerably decreased viability after WP1066 treatment. However, BTICs had fewer responses than BCs. No additive or synergistic effect was observed for combination therapy of WP1066 and cisplatin. WP1066 effectively abrogated p-STAT3 expression. An increased apoptosis and decreased Survivin expression were observed after WP1066 treatment. Knockdown of STAT3 also decreased cell survival, supporting the critical role of STAT3 in sustaining ependymoma cells. In this study, we observed a cytotoxic effect of STAT3 inhibitor on ependymoma BTICs and BCs. There is urgent need to develop new therapeutic agents for pediatric ependymoma. STAT3 inhibitors may be a new group of drugs for clinical application.</P>