Abstract 5280: TERT promoter mutations are an independent predictor of distant metastasis in Middle Eastern papillary thyroid microcarcinoma

Background: Papillary thyroid microcarcinomas (PTMCs) have been attributed to the recent increased incidence of thyroid cancer. Although indolent, a subset of PTMC could potentially develop distant metastasis (DM). This study aimed to evaluate the clinico-pathological features and molecular characteristics of PTMC and identify the risk factors for DM in PTMC patients from Middle Eastern ethnicity.

Methods: We retrospectively analyzed 210 patients with histologically confirmed PTMC. Clinico-pathological associations for DM, BRAF mutation and TERT mutation were analyzed successfully in 184 patients. Multivariate analysis was performed using Cox proportional hazards model and logistic regression analysis.

Results: Among the PTMC patients included in this cohort, DM was noted in 6.0%(11/184), whereas tumor relapse occurred in 29/184 (15.8%). Of the 11 cases with DM, lung metastasis occurred in 8 cases, bone metastasis in 2 cases and brain metastasis in 1 case. Presence of extrathyroidal extension and older age were significantly associated with DM. Molecular analysis showed BRAF V600E mutations to be the most frequent, being detected in 45.7% (84/184). TERT promoter mutations were detected in 16 (8.7%) cases and were significantly associated with DM and shorter metastasis-free survival in multivariate analysis.

Conclusions: Our study indicates a surprisingly high frequency of TERT promoter mutation in Saudi patients with PTMC. Identifying TERT promoter mutations as an independent predictor of DM in patients with microcarcinoma could explain the inherent aggressive nature of PTMC from Middle Eastern ethnicity and magnify its role in patient risk stratification, which might help in improving therapeutic strategy for these patients.

Citation Format: Saeeda Omer Ahmed, Abdul K. Siraj, Sandeep K. Parvathareddy, Kaleem Iqbal, Zeeshan Qadri, Maha Al-Rasheed, Sarah Siraj, Saravanan Thangavel, Roxanne Diaz, Allianah Benito, Ingrid F. Victoria, Khawla S. AlKuraya. TERT promoter mutations are an independent predictor of distant metastasis in Middle Eastern papillary thyroid microcarcinoma [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 5280.

APC truncating mutations in Middle Eastern Population: Tankyrase inhibitor is an effective strategy to sensitize APC mutant CRC To 5-FU chemotherapy

Colorectal Cancer (CRC) is highly heterogeneous for which prognosis is dependent mainly on clinical staging. There is a need to stratify subpopulations of CRC on molecular basis to better predict outcome and therapy response. Truncating mutations in adenomatous polyposis coli (APC) are well-described events in CRC carcinogenesis. Clinical and genotypic characterization of Middle Eastern CRC based on presence and type of APC was determined in 412 CRC tumors using modern next generation sequencing. APC truncating mutations were identified in 58.2% (240/412) of CRCs. Overall, mutation was significant predictor of superior overall survival. Further, the type of APC mutations (short or long) did not have impact on clinical outcome. However, in vitro analysis showed difference between CRC cell lines carrying short truncating APC vs CRC cells that carry long truncating APC mutation in response to 5-flourouracil (5-FU). Importantly, we were able to overcome the resistance to 5-FU seen in CRC cells carrying short APC by tankyrase inhibitor, XAV939, thereby inhibiting Wnt/β-catenin signaling cascade. Overall, our results showed that APC mutation status plays an important role in predicting overall survival in Middle Eastern population. Furthermore, in vitro data showed that selective targeting of APC mutated CRC by tankyrase inhibitor can be an effective strategy to overcome 5-FU resistance in CRC cells.

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.

Introduction of vincristine mini-bags and an assessment of the subsequent risk of extravasation

INTRODUCTION

Numerous international organisations have advocated the preparation of vincristine in small volume intravenous bags in order to eliminate inadvertent intrathecal administration. However, the risk of extravasation is a significant deterrent, and adoption of this practice has been variable and only hesitantly accepted in the clinical setting.

PURPOSE

We carried out a study with the aims of establishing the incidence of reported extravasation of vincristine administration to paediatric and adult patients in mini-bags; here we describe motivating factors and barriers faced by clinical staff. The secondary aim was to support the need for change and implementation of the international recommendations.

METHODS

Chemotherapy-certified nurses completed a survey spanning August 2009 to August 2011, to ascertain the incidence of extravasation associated with the administration of vincristine in mini-bags.

RESULTS

This period captured 421 occasions of vincristine administration in 25-ml or 50-ml mini-bags (in 0.9% sodium chloride). The median age of patients was 13 years (range 2.5 months to 99 years). Vincristine was administered through peripheral lines (26.4%), portacath (52.0%), PICC line (15.9%) and Hickman line (5.7%). The majority of infusions were over at least 10 minutes (50.1%). There were no cases of extravasation reported.

CONCLUSIONS

The administration of vincristine in small volume intravenous bags was safe, practical, and feasible in all patient groups. The successful implementation of the international recommendations for vincristine administration in mini-bags to eliminate potential inadvertent intrathecal administration was dependent on stakeholder buy-in.

Apigenin induces apoptosis via downregulation of S-phase kinase-associated protein 2-mediated induction of p27Kip1 in primary effusion lymphoma cells

OBJECTIVE

The mechanisms that regulate mitogenic and antiapoptotic signals in primary effusion lymphoma (PEL) are not well known. In efforts to identify novel approaches to block the proliferation of PEL cells, we assessed the effect of apigenin (4',5,7-trihydroxyflavone), a flavonoid on a panel of PEL cell lines.

MATERIALS AND METHODS

We studied the effect of apigenin on four PEL cell lines. Apoptosis was measured by annexin V/PI dual staining and DNA laddering. Protein expression was measured by immunoblotting.

RESULTS

Apigenin induced apoptosis in PEL cell lines in a dose dependent manner. Such effects of apigenin appeared to result from suppression of constitutively active kinase AKT resulting in down-regulation of SKP2, hypo-phosphorylation of Rb and accumulation of p27Kip1. Apigenin treatment of PEL cells caused dephosphorylation of p-Bad protein leading to down regulation of the anti-apoptotic protein, Bcl-2 and an increase in Bax/Bcl2 ratio. Apigenin treatment also triggered Bax conformational change and subsequently translocation from cytosole to mitochondria causing loss of mitochondrial membrane potential with subsequent release of cytochrome c. Released cytochrome c onto the cytosole activated caspase-9 and caspase-3, followed by polyadenosin-5'-diphosphate-ribose polymerase (PARP) cleavage. Finally, treatment of PEL cells with apigenin down-regulated the expression of inhibitor of apoptosis protein (IAPs).

CONCLUSIONS

Altogether, these data suggest a novel function for apigenin, acting as a suppressor of AKT/PKB pathway in PEL cells, and raise the possibility that this agent may have a future therapeutic role in PEL and possibly other malignancies with constitutive activation of the AKT/PKB pathway.

Toxicity and IGR effect of two new neem products against Aedes aegypti (PCSIR strain)

Crude extract and isolated compounds from neem, Azadirachta indica and Melia azedarach (Meliaceae) are being tested in various countries. The present study deals with the effect of two new compounds and their parent fraction from the fresh winter neem leaves, isolated by Siddiqui et. al., 1986. The LC50 of NFD is 0.58 ppm, nimocinolide 0.625 ppm and isonimocinolide 0.47 ppm. Abnormal larvae, pupae and intermediates were also found.