Abstract 5178: Multifocality is an independent predictor of regional lymph node metastasis in Middle Eastern papillary thyroid carcinoma

Background: Papillary thyroid carcinoma (PTC) is treatable, with favorable prognosis and very low disease-specific mortality. However, PTC recurrence is relatively common in loco-regional and distant sites. Although multifocality is a common occurrence in PTC, its prognostic impact remains controversial. In addition, data on prevalence and prognostic significance of multifocality in PTC from Middle Eastern ethnicity is unknown. Therefore, the aim of this study was to investigate the prognostic value of multifocality in PTC larger than 1cm and papillary thyroid microcarcinoma (PTMC) in our center.

Methods: A cohort of 1515 patients who underwent total thyroidectomy were retrospectively reviewed. Aggressive histopathologic variants of PTC were excluded to avoid their potential confounding effect on clinical outcomes. We identified 1087 patients who had PTC with primary tumor exceeding 1cm and 150 patients with PTMC, with medium follow up of 9.2 years. In each group, we compared patients with unifocal and multifocal disease. Clinico-pathological and molecular correlations were analyzed. Logistic regression analysis was used to assess the relation between multifocal tumors and lymph node metastasis.

Results: The incidence of multifocality in PTC larger than 1cm was 48.3% (525/1087), whereas it was 38.7% (58/150) in PTMCs. In patients with PTC > 1cm, multifocality was significantly associated with aggressive markers such as extrathyroidal extension (p < 0.0001), lymphovascular invasion (p = 0.0047), lymph node (LN) metastasis (p = 0.0006), distant metastasis (p = 0.0305) and BRAF mutation (p = 0.0113). In analogous analysis of patients with PTMC, multifocality was significantly associated with extrathyroidal extension (p < 0.0001), LN metastasis (p = 0.0005) and BRAF mutation (p = 0.0006). In both sub-groups, disease recurrence and overall survival did not differ between unifocal and multifocal group. Multivariate analysis showed that multifocality was an independent predictor of LN metastasis (Odds ratio (OR) = 1.31; 95% confidence interval (CI) = 1.00 - 1.71; p = 0.0472 for PTC > 1cm and OR = 1.88; 95% CI = 1.00 - 3.54; p = 0.0491 for PTMC).

Conclusions: Tumor multifocality is frequently observed in Middle Eastern PTC and PTMC and is a predictive factor for LN metastasis in PTC. Given the predictive value of multifocality in Middle Eastern ethnicity, aggressive therapy and intensive follow-up should be considered for both PTC and PTMC with multifocality. Regional LN metastasis should be closely monitored and prophylactic central lymph node dissection could be considered in these patients.

Citation Format: Pratheeshkumar Poyil, Abdul K Siraj, Sandeep Kumar Parvathareddy, Divya Padmaja, Saravanan Thangavel, Rafia Begum, Roxanne Diaz, Khadija Al-Obaisi, Khawla S. Al-Kuraya. Multifocality is an independent predictor of regional lymph node metastasis in Middle Eastern papillary thyroid carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5178.

Development of a Critical Appraisal Tool (AIMRDA) for the Peer-Review of Studies Assessing the Anticancer Activity of Natural Products: A Step towards Reproducibility

The journal of APJCP (Asian Pacific Journal of Cancer Prevention) focuses to gather relevant and up-to-date novel information’s related to cancer sciences. The research methodologies and approaches adopted by the researcher are prone to variation which may be desirable in the context of novel scientific findings however, the reproducibility for these studies needs to be unified and assured. The reproducibility issues are highly concerned when preclinical studies are reported in cancer, for natural products in particular. The natural products and medicinal plants are prone to a wide variation in terms of phytochemistry and phyto-pharmacology, ultimately affecting the end results for cancer studies. Hence the need for specific guidelines to adopt a best-practice in cancer research are utmost essential. The current AIMRDA guidelines aims to develop a consensus-based tool in order to enhance the quality and assure the reproducibility of studies reporting natural products in cancer prevention. A core working committee of the experts developed an initial draft for the guidelines where more focus was kept for the inclusion of specific items not covered in previous published tools. The initial draft was peer-reviewed, experts-views provided, and improved by a scientific committee comprising of field research experts, editorial experts of different journals, and academics working in different organization worldwide. The feedback from continuous online meetings, mail communications, and webinars resulted a final draft in the shape of a checklist tool, covering the best practices related to the field of natural products research in cancer prevention and treatment. It is mandatory for the authors to read and follow the AIMRDA tool, and be aware of the good-practices to be followed in cancer research prior to any submission to APJCP. Though the tool is developed based on experts in the field, it needs to be further updated and validated in practice via implementation in the field.

Abstract 1176: CHD4 predicts aggressiveness in PTC patients and promotes cancer stemness and EMT in PTC cells

Papillary thyroid carcinoma (PTC) is the most common histologic subtype, accounting for nearly 90% of thyroid cancer. Chromodomain-helicase-DNA-binding protein 4 (CHD4), a core subunit of the nucleosome remodeling and deacetylation (NuRD) complex is highly expressed in several cancers. However, its role in the pathogenesis and progression of PTC has not been investigated. Immunohistochemistry was performed to assess CHD4 protein expression in PTC using a tissue microarray. We also performed in vitro analysis to investigate the role of CHD4 in regulating cancer stemness and EMT in PTC cells. CHD4 overexpression was observed in 45.3% (650/1436) of PTCs, and was associated with aggressive clinico-pathological parameters and worse outcome. Functional analysis using PTC cell lines showed that forced expression of CHD4 promoted cell proliferation, spheroid growth, migration, invasion, and progression of epithelial to mesenchymal transition (EMT) in PTC cells whereas its knockdown reversed the effect. Methylation of E-cadherin was associated with loss of expression in CHD4 expressing cells, while CHD4 depletion reactivated E-cadherin expression. Most importantly, knockdown of mesenchymal transcriptional factors, Snail1 or Zeb1, attenuated the spheroid growth in CHD4 expressing PTC cells, showing a potential link between EMT activation and stemness maintenance in PTC. These findings suggest that CHD4 might be a promising therapeutic target in the treatment of patients with an aggressive subtype of PTC.

Citation Format: Pratheeshkumar Poyil, Abdul K. Siraj, Sasidharan Padmaja Divya, Sandeep Kumar Parvathareddy, Roxanne Diaz, Rafia Begum, Khadija Al-Obaisi, Saravanan Thangavel, Saif S. Al-Sobhi, Fouad Al-Dayel, Khawla S. Al-Kuraya. CHD4 predicts aggressiveness in PTC patients and promotes cancer stemness and EMT in PTC cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1176.

Abstract 2933: KLF5 and its association with HIF-1α promotes PTC progression and metastatic potential through AKT activation

Thyroid cancer is the second most common malignancy among females in Saudi Arabia, with Papillary thyroid carcinoma (PTC) accounting for 80-90%. Kruppel-like factor 5 (Klf5) is a transcription factor that plays a critical role in cell transformation, proliferation, and oncogenesis. Immunohistochemical analysis of KLF5 was performed in 1219 PTC cases. KLF5 over-expression was noted in 65.1% (793/1219) of PTCs, and was significantly associated with tall-cell variant (p <0.0001), extrathyroidal extension (p = 0.0003), lymph node metastasis (p < 0.0001) and stage IV tumors (p < 0.0001). A significant association was also noted with HIF-1α over-expression (p = 0.0492). Interestingly, KLF5 over-expressing tumors showed poor disease-free survival (p = 0.0066). Functional studies in PTC cell lines showed that KLF5 co-immunoprecipitated with HIF-1α. Knockdown of KLF5 decreased the expression of HIF-1α while KLF5 was not affected by HIF-1α inhibition, suggesting that KLF5 is a functional upstream of HIF-1α. Down-regulation of KLF5 using a specific inhibitor, ML264 or siRNA inhibited cell migration, invasion, and angiogenesis. Also, the treatment of PTC cell lines with ML264 resulted in inhibition of proliferation and induction of apoptosis in a dose-dependent manner. Furthermore, the silencing of KLF5 significantly decreased the self-renewal ability of spheroids generated from PTC cells. Our findings confer that KLF5 may be a potential therapeutic target for the treatment of papillary thyroid cancer.

Citation Format: Pratheeshkumar Poyil, Abdul K Siraj, Divya Padmaja, Sandeep Kumar Parvathareddy, Saravanan Thangavel, Roxanne Melosantos, Ingrid G. Victoria, Rafia Begum, Fouad Al-Dayel, Khawla S. Al-Kuraya. KLF5 and its association with HIF-1α promotes PTC progression and metastatic potential through AKT activation [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2933.

SUN-132 KLF5 Is a Poor Prognostic Marker and Therapeutic Target for Middle Eastern Papillary Thyroid Carcinoma

Thyroid cancer is the second most common malignancy among females in Saudi Arabia, with Papillary thyroid carcinoma (PTC) accounting for 80-90%. The Kruppel-like factor 5 (Klf5) is a transcription factor that play a critical role in cell transformation, proliferation and oncogenesis. Immunohistochemical analysis of KLF5 was performed in 1219 PTC cases. KLF5 over-expression was noted in 65.1% (793/1219) of PTCs, and was significantly associated with tall-cell variant (p <0.0001), extrathyroidal extension (p = 0.0003), lymph node metastasis (p < 0.0001) and stage IV tumors (p < 0.0001). Significant association was also noted with HIF-1α over-expression (p = 0.0492). Interestingly, KLF5 over-expressing tumors showed poor disease-free survival (p = 0.0066). Functional studies in PTC cell lines showed that KLF5 co-immunoprecipitated with HIF-1α. Knockdown of KLF5 decreased the expression of HIF-1α while KLF5 was not affected by HIF-1α inhibition, suggesting that KLF5 is a functional upstream of HIF-1α. Down-regulation of KLF5 using specific inhibitor, ML264 or siRNA inhibited cell invasion and migration. In addition, treatment of PTC cell lines with ML264 resulted in inhibition of proliferation and induction of apoptosis in a dose-dependent manner. Furthermore, silencing of KLF5 significantly decreased the self-renewal ability of spheroids generated from PTC cells. Our findings confer that KLF5 may be a potential therapeutic target for the treatment of papillary thyroid cancer.

Abstract 4286: TGFβ induced SMAD4 dependent apoptosis proceeded by EMT in colorectal cancer

Colorectal cancer (CRC) is one of the leading cause of cancer-related deaths Worldwide. In Saudi Arabia, CRC is more aggressive and presents at younger age, warranting new treatment strategies. Role of TGFβ/Smad4 signaling pathway in initiation and progression of CRC is well documented. Current study examined the role of TGFβ/Smad4 signaling pathway in a large cohort of Saudi CRC, followed by in vitro analysis to dissect the dual role of TGFβ on inducing epithelial to mesenchymal transition (EMT) and apoptosis. In this study, we investigated Smad4 alterations and their association with clinicopathological outcomes in a large cohort of CRC samples using targeted capture sequencing, Fluorescent in-situ hybridisation and immunohistochemistry. Our study demonstrated high frequency of Smad4 alterations with low expression of Smad4 protein identifying a sub-group of aggressive CRC to be an independent marker for poor prognosis. Functional studies using CRC cells show that TGFβ induces Smad4 dependent EMT followed by apoptosis. Induction of mesenchymal transcriptional factors, Snail1 and Zeb1 was essential for TGFβ-induced apoptosis. Our results indicate that KLF5 acts as an oncogene in CRC cells regardless of Smad4 expression and inhibition of KLF5 is requisite for TGFβ-induced apoptosis. Furthermore, TGFβ/Smad4 signal inhibits the transcription of KLF5 that in turn switches Sox4 from tumor promoter to suppressor. A high incidence of Smad4 alterations were found in the Saudi CRC patients. Functional study results indicate that TGFβ induces Smad4 dependent EMT followed by apoptosis in CRC cells.

Citation Format: Pratheeshkumar Poyil, Abdul K. Siraj, Divya Sasidharan Padmaja, Sandeep Kumar Parvathareddy, Rong Bu, Tariq Masoodi, Yan Kong, Saravanan Thangavel, Saeeda Omer Ahmed, Nasser Al-Sanea, Luai H. Ashari, Alaa Abduljabbar, Samar Alhomoud, Fouad Al-Dayel, Khawla S. Al-Kuraya. TGFβ induced SMAD4 dependent apoptosis proceeded by EMT in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4286.

Abstract 1329: Inhibition of papillary thyroid cancer cells progression by targeting skp2 via ros-erk-chop-dr5 pathways

S-phase kinase protein 2 (SKP2), is an F-box protein with proteasomal properties and has been found to be overexpressed in a variety of cancers. However its role in papillary thyroid cancer (PTC) has not been elucidated. Therefore, inactivation of SKP2 could be a viable strategy for the treatment of PTC. In the present study, we investigated the role of SKP2 and its ubiquitin-proteasome pathway in PTC using a tissue microarray cohort of 1022 PTC samples, PTC cell lines and Nude mouse model. Our immunohistochemistry data showed that SKP2 was over-expressed in 75.1% of PTC cases and was clinically, significantly associated with extra thyroidal extension (p=0.0331), Tall cell variant (p=0.0070), and presence in surgical margins (p=0.0347). Bortezomib as well as SKP2 specific siRNA caused downregulation of SKP2 leading to dose-dependent growth inhibition and induction of apoptosis via mitochondrial apoptotic pathway in PTC cell lines. Furthermore, we found that treatment of PTC cells with Bortezomib caused up-regulation of DR5 via generation of reactive oxygen species (ROS). Finally, Bortezomib treatment augmented TRAIL mediated anti-cancer effect on PTC xenograft tumor growth in nude mice. These data suggest that Bortezomib is a viable therapeutic option for the treatment of PTC either alone or in combination with other apoptotic agents such as TRAIL.

Note: This abstract was not presented at the meeting.

Citation Format: Pratheeshkumar Poyil, Rong Bu, Abdul K. Siraj, Sandeep Kumar P, Khawla S. Al-Kuraya. Inhibition of papillary thyroid cancer cells progression by targeting skp2 via ros-erk-chop-dr5 pathways [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1329. doi:10.1158/1538-7445.AM2017-1329

Sorafenib and FH535 in combination act synergistically on hepatocellular carcinoma by targeting cell bioenergetics and mitochondrial function

Treatment of advanced hepatocellular carcinoma (HCC) remains a challenge due to the high tumor heterogeneity. In the present study, we aim to evaluate the impact of the β-catenin inhibitor, FH535, alone or in combination with the Ras/Raf/MAPK inhibitor Sorafenib, on the bioenergetics profiles of the HCC cell lines Huh7 and PLC/PRF/5. Single low-dose treatments with FH535 or Sorafenib promoted different effects on mitochondrial respiration and glycolysis in a cell type specific manner. However, the combination of these drugs significantly reduced both mitochondrial respiration and glycolytic rates regardless of the HCC cells. The significant changes in mitochondrial respiration observed in cells treated with the Sorafenib-FH535 combination may correspond to differential targeting of ETC complexes and changes in substrate utilization mediated by each drug. Moreover, the bioenergetics changes and the loss of mitochondrial membrane potential that were evidenced by treatment of HCC cells with the combination of FH535 and Sorafenib, preceded the induction of cell apoptosis. Overall, our results demonstrated that Sorafenib-FH535 drug combination induce the disruption of the bioenergetics of HCC by the simultaneous targeting of mitochondrial respiration and glycolytic flux that leads the synergistic effect on inhibition of cell proliferation. These findings support the therapeutic potential of combinatory FH535-Sorafenib treatment of the HCC heterogeneity by the simultaneous targeting of different molecular pathways.

Downregulation of NEDD9 by apigenin suppresses migration, invasion, and metastasis of colorectal cancer cells

Apigenin is a natural flavonoid which possesses multiple anti-cancer properties such as anti-proliferation, anti-inflammation, and anti-metastasis in many types of cancers including colorectal cancer. Neural precursor cell expressed developmentally downregulated 9 (NEDD9) is a multi-domain scaffolding protein of the Cas family which has been shown to correlate with cancer metastasis and progression. The present study investigates the role of NEDD9 in apigenin-inhibited cell migration, invasion, and metastasis of colorectal adenocarcinoma DLD1 and SW480 cells. The results show that knockdown of NEDD9 inhibited cell migration, invasion, and metastasis and that overexpression of NEDD9 promoted cell migration and invasion of DLD1 cells and SW4890 cells. Apigenin treatment attenuated NEDD9 expression at protein level, resulting in reduced phosphorylations of FAK, Src, and Akt, leading to inhibition on cell migration, invasion, and metastasis of both DLD1 and SW480 cells. The present study has demonstrated that apigenin inhibits cell migration, invasion, and metastasis through NEDD9/Src/Akt cascade in colorectal cancer cells. NEDD9 may function as a biomarker for evaluation of cancer aggressiveness and for selection of therapeutic drugs against cancer progression.

Abstract 2798: Quercetin inhibits Cr(VI)-induced malignant transformation of human lung epithelial cells by targeting miR-21-Pdcd4 signaling pathway

Hexavalent chromium [Cr(VI)] is an important human carcinogen associated with pulmonary diseases and lung cancer. Cancer prevention using natural products has become an integral part of cancer control. Quercetin is one of the most abundant dietary flavonoids widely present in many fruits and vegetables, possesses potent antioxidant activity capable of protecting normal cells from various stimuli-induced oxidative stress and cell death. MicroRNA-21 (miR-21) is a key regulator of oncogenic processes. It is significantly elevated in the majority of human tumors and functionally linked to cellular proliferation, invasion and migration. Studies have shown that miR-21 exerts its oncogenic activity by targeting the tumor suppressor gene programmed cell death 4 (Pdcd4). The present study examined the effect of quercetin on the inhibition of Cr(VI) induced carcinogenesis and the role of miR-21-Pdcd4 signaling involved. Our results showed that quercetin decreased ROS generation induced by Cr(VI) exposure in Beas-2B cells. Chronic Cr(VI) exposure induced malignant cell transformation, increased miR-21 expression and caused inhibition of Pdcd4, which were significantly inhibited by the treatment of quercetin in a dose dependent manner. Stable knockdown of miR-21 or overexpression of pdcd4 in Beas-2B cells significantly reduced the Cr(VI) induced cell transformation. Furthermore, Quercetin also inhibited the Cr(VI) induced beta-catenin/TCF-dependent transcription. Taken together, these results demonstrate that quercetin is able to protect Beas-2B cells from Cr(VI)-induced carcinogenesis by targeting miR-21-Pdcd4 signaling.

Keywords: Hexavalent chromium, Quercetin, miR-21-Pdcd4 signaling

Citation Format: Pratheeshkumar Poyil. Quercetin inhibits Cr(VI)-induced malignant transformation of human lung epithelial cells by targeting miR-21-Pdcd4 signaling pathway. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2798. doi:10.1158/1538-7445.AM2015-2798

Abstract 5360: Ethanol enhances arsenic-induced mutagenesis in colon

Health effects due to environmental exposure to arsenic are a major health concern world-wide. Arsenic has been known to induce carcinogenesis and enhance tumor development via complex and unclear mechanism. As one of the common nutritional factors, ethanol is also a well-documented risk factor for many malignancies. However, little is known on the effects of co-exposure to arsenic and ethanol in mutagenesis and carcinogenesis. In this study, we investigate the mutagenic effect of co-exposure to arsenic and ethanol in vivo and in vitro. Results show that ethanol could markedly enhance arsenic-induced mutagenesis in colon in Big Blue Mice. This response related to intracellular reactive oxygen species (ROS) generation, NAPDH oxidase activation, and DNA damage/repair functional changes.

We conclude that ethanol enhances arsenic-induced mutagenesis in colon in vivo. These results indicated that alcohol consumption should be taken into consideration in the investigation on arsenic-induced carcinogenesis in arsenic-exposure population.

Citation Format: Lei Wang, Lisha Kuang, Young-Ok Son, John Andrew Hitron, Pratheeshkumar Poyil, Zhuo Zhang, Jia Luo, Zhigang Wang, Xianglin Shi. Ethanol enhances arsenic-induced mutagenesis in colon. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5360. doi:10.1158/1538-7445.AM2014-5360

Cadmium induces carcinogenesis in BEAS-2B cells through ROS-dependent activation of PI3K/AKT/GSK-3β/β-catenin signaling

Cadmium has been widely used in industry and is known to be carcinogenic to humans. Although it is widely accepted that chronic exposure to cadmium increases the incidence of cancer, the mechanisms underlying cadmium-induced carcinogenesis are unclear. The main aim of this study was to investigate the role of reactive oxygen species (ROS) in cadmium-induced carcinogenesis and the signal transduction pathways involved. Chronic exposure of human bronchial epithelial BEAS-2B cells to cadmium induced cell transformation, as evidenced by anchorage-independent growth in soft agar and clonogenic assays. Chronic cadmium treatment also increased the potential of these cells to invade and migrate. Injection of cadmium-stimulated cells into nude mice resulted in the formation of tumors. In contrast, the cadmium-mediated increases in colony formation, cell invasion and migration were prevented by transfection with catalase, superoxide dismutase-1 (SOD1), or SOD2. In particular, chronic cadmium exposure led to activation of signaling cascades involving PI3K, AKT, GSK-3β, and β-catenin and transfection with each of the above antioxidant enzymes markedly inhibited cadmium-mediated activation of these signaling proteins. Inhibitors specific for AKT or β-catenin almost completely suppressed the cadmium-mediated increase in total and active β-catenin proteins and colony formation. Moreover, there was a marked induction of AKT, GSK-3β, β-catenin, and carcinogenic markers in tumor tissues formed in mice after injection with cadmium-stimulated cells. Collectively, our findings suggest a direct involvement of ROS in cadmium-induced carcinogenesis and implicate a role of AKT/GSK-3β/β-catenin signaling in this process.

Ethanol enhances tumor angiogenesis in vitro induced by low-dose arsenic in colon cancer cells through hypoxia-inducible factor 1 alpha pathway

Health effects due to environmental exposure to arsenic are a major global health concern. Arsenic has been known to induce carcinogenesis and enhance tumor development via complex and unclear mechanism. Ethanol is also a well-established risk factor for many malignancies. However, little is known about the effects of coexposure to arsenic and ethanol in tumor development. In this study, we investigate the signaling and angiogenic effect of coexposure of arsenic and ethanol on different colon cancer cell lines. Results show that ethanol markedly enhanced arsenic-induced tumor angiogenesis in vitro. These responses are related to intracellular reactive oxygen species (ROS) generation, NADPH oxidase activation, and upregulation of PI3K/Akt and hypoxia-inducible factor 1 alpha (HIF-1α) signaling. We have also found that ethanol increases the arsenic-induced expression and secretion of angiogenic signaling molecules such as vascular endothelial growth factor, which further confirmed the above observation. Antioxidant enzymes inhibited arsenic/ethanol-induced tumor angiogenesis, demonstrating that the responsive signaling pathways of coexposure to arsenic and ethanol are related to ROS generation. We conclude that ethanol is able to enhance arsenic-induced tumor angiogenesis in colorectal cancer cells via the HIF-1α pathway. These results indicate that alcohol consumption should be taken into consideration in the investigation of arsenic-induced carcinogenesis in arsenic-exposed populations.