Comparison of 10 and 14 days of triple therapy versus 10 days of sequential therapy for Helicobacter pylori eradication: A prospective randomized study

BACKGROUND/AIMS

The aim of the present study was to compare between the efficacy and tolerability of a sequential therapy (ST) as the first-line treatment for adults with Helicobacter pylori infection and that of standard triple therapy (TT).

MATERIALS AND METHODS

This was a prospective, randomized open-label, single-center study. We enrolled 206 patients who were divided into the following three treatment groups: Group A (pantoprazole 40 mg bid (twice daily), amoxicillin 1 g bid, and clarithromycin 500 mg bid for 10 d), Group B (the same TT as Group A for 14 d), and Group C (pantoprazole 40 mg bid and amoxicillin 1 g bid for 5 d, followed by pantoprazole 40 mg bid, clarithromycin 500 mg bid, and metronidazole 500 mg bid for additional 5 d).

RESULTS

Intention-to-treat (ITT) analysis revealed that 14 d of TT achieved a higher eradication rate than 10 d of ST (54.8% vs. 50.7%), but the difference was not statistically significant (p=0.623); further, 10 d of TT achieved 45% eradication rate. Per-protocol (PP) analysis revealed that the success rate for 10 d of ST was more than that for 10 d of TT (70.6% vs. 65%; p=0.571); however, the success rate for 10 d of TT was not statistically different from that for 14 d of TT. The eradication rates achieved in the ITT analysis were lower than those achieved in the PP analysis for 10 (45% vs. 65%) or 14 (54.7% vs. 69%) d of TT or for 10 d of ST (50.7% vs. 70.6%). No statistically significant difference was observed. Adverse effects and compliance were not significantly different among the three groups.

CONCLUSION

Neither 10 d of ST nor 14 d of TT achieved the optimum H. pylori eradication rate.

Evaluation of cationic channel TRPV2 as a novel biomarker and therapeutic target in Leukemia-Implications concerning the resolution of pulmonary inflammation

Patients treated during leukemia face the risk of complications including pulmonary dysfunction that may result from infiltration of leukemic blast cells (LBCs) into lung parenchyma and interstitium. In LBCs, we demonstrated that transient receptor potential vanilloid type 2 channel (TRPV2), reputed for its role in inflammatory processes, exhibited oncogenic activity associated with alteration of its molecular expression profile. TRPV2 was overexpressed in LBCs compared to normal human peripheral blood mononuclear cells (PBMCs). Additionally, functional full length isoform and nonfunctional short form pore-less variant of TRPV2 protein were up-regulated and down-regulated respectively in LBCs. However, the opposite was found in PBMCs. TRPV2 silencing or pharmacological targeting by Tranilast (TL) or SKF96365 (SKF) triggered caspace-mediated apoptosis and cell cycle arrest. TL and SKF inhibited chemotactic peptide fMLP-induced response linked to TRPV2 Ca²⁺ activity, and down-regulated expression of surface marker CD38 involved in leukemia and lung airway inflammation. Challenging lung airway epithelial cells (AECs) with LBCs decreased (by more than 50%) transepithelial resistance (TER) denoting barrier function alteration. Importantly, TL prevented such loss in TER. Therefore, TRPV2 merits further exploration as a pharmacodynamic biomarker for leukemia patients (with pulmonary inflammation) who might be suitable for a novel [adjuvant] therapeutic strategy based on TL.

Anticancer Activity of Camel Milk via Induction of Autophagic Death in Human Colorectal and Breast Cancer Cells

Background/Objective:

Camel milk is traditionally known for its human health benefits and believed to be a remedy for various human ailments including cancer. The study was aimed to evaluate the inhibitory effects of commercially available camel milk on cancer cells and its underlying mechanism(s).

Materials and Methods:

Two cell lines: colorectal cancer HCT 116 and breast cancer MCF-7 were cultured with different doses of camel milk. The effects of camel milk on cell death were determined by MTT assay, viability by trypan blue exclusion assay and migration by in vitro scratch assay. The mechanism was elucidated by western blotting and confocal microscopy was used to confirm autophagy.

Results:

Camel milk significantly reduced proliferation, viability as well as migration of both the cells. The accumulation of LC3-II protein along with reduction in expression of p62 and Atg 5-12, the autophagy proteins implied induction of autophagy. The (GFP)-LC3 puncta detected by confocal microscopy confirmed the autophagosome formation in response to camel milk treatment.

Conclusion:

Camel milk exerted antiproliferative effects on human colorectal HCT 116 and breast MCF-7 cancer cells by inducing autophagy.

Abstract 2491: Nuclear exporter protein XPO1 a novel prognostic and therapeutic target in gastric cancer

The high mortality rate associated with Gastric Cancer (GC) indicates the urgent need for actionable therapeutic targets. The nuclear exporter protein exportin 1 (XPO1/CRM1) is the exclusive exporter of many tumor suppressor proteins (TPSs) and growth regulators. XPO1 is often over-expressed in different malignancies leading to aberrant cytoplasmic localization of TSPs and subsequent inactivation. A detailed analysis on the correlation of XPO1 with inflammation-metaplasia-dysplasia-carcinoma sequence progression was performed using immunohistochemistry in 70 GC cases: (a) 10 cases from normal gastric mucosa, (b) 10 cases of stomach with intestinal metaplasia with and without inflammation, (c) 10 cases of mucosa with low-grade dysplasia (d) 10 cases of mucosa with high-grade dysplasia, (e) 10 cases of gastric adenocarcinoma and (f) 20 cases of metastatic gastric carcinoma. A correlation between XPO1 expression, the pathological and clinical features of the disease as well as survival were analyzed. Gastric cancer cell lines were exposed to the Selective Inhibitors of Nuclear Export (SINE) compounds (selinexor, KPT-8602, KPT-185, or the natural agent, leptomycin B (LMB), then analyzed using cytotoxicity and molecular assays. In addition, the activity of selinexor was evaluated in a sub-cutaneous xenograft of gastric cancer cell line NCI-N87. XPO1 served as a prognostic marker for poor outcome as positive staining of XPO1 in GC correlated with aggressive behavior of the disease. Targeting XPO1 using SINE compounds or LMB resulted in inhibition of GC cellular growth (IC50<200 nM), induction of apoptosis and suppression of colony formation (p<0.01). Molecular analysis revealed nuclear retention of several important TSPs, induction of pro-apoptotic proteins and suppression of pro-survival factor Bcl-2. Selinexor given orally at doses of 15 mg/kg twice a week for three weeks caused statistically significant reduction of NCI-N87 tumors in mice (p<0.05). Efficacy studies of SINE compounds in patient derived models of GC are ongoing. Our findings strongly demonstrate the potential of XPO1 to serve not only as a prognostic marker but also as a therapeutic marker in GC that warrants further clinical investigations.

Citation Format: Irfana Muqbil, Zaid Mahdi, Rahman Choudhary, Erkan Baloglu, William Senapedis, Yosef Landesman, Sharon Shacham, Michael Kauffman, Steve Kim, Rafic Beydoun, Richard N. Berri, Anthony Shields, Ramzi M. Mohammad, Asfar S. Azmi. Nuclear exporter protein XPO1 a novel prognostic and therapeutic target in gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2491.

Abstract 4368: PAK4-NAMPT dual inhibition as a feasible strategy for treatment of resistant pancreatic neuroendocrine tumors

Our studies in pancreatic neuroendocrine tumor (pNET) cell lines demonstrate hyper-activation of the Rho GTPase effector p21 activated kinase 4 (PAK4) and the nicotinamide adenine dinucleotide (NAD) salvage pathway rate limiting enzyme nicotinamide phosphoribosyltransferase (NAMPT). The PAK4 protein is known to regulate a myriad of signaling proteins in the mTOR pathway including mTORC1, mTORC2, PI3K, and IGF-1. Similarly, NAMPT is recognized to regulate mTOR through energy sensor protein, AMPK. In this study, pNET cell lines QGP-1 and Bon-1 were subjected to either PAK4 RNA interference (RNAi), PAK4-NAMPT dual inhibitors (the clinical compound KPT-9274 or an analog KPT-7523) or the PAK4 specific inhibitor, PF-3738309 and NAMPT specific inhibitor FK866 in the presence or absence of mTOR inhibitors (everolimus or INK128). Gene expression profiling and phospho-proteomic analyses were performed to capture molecular changes post single or combination treatments. The anti-tumor activity of KPT-9274-everolimus was evaluated in a subcutaneous xenograft mouse model derived from QGP-1 and Bon-1 cells. PAK4 RNAi suppressed proliferation and restored everolimus sensitivity in pNET cell lines. The dual inhibitors were effective in reducing proliferation and inducing apoptosis. KPT-9274 or KPT-7523 could synergistically enhance the anti-tumor activity of everolimus or INK128 in pNET cell lines [CI <1]. Molecular analysis of the combination treatment showed down-regulation of known everolimus resistance drivers such as mTORC1, mTORC2, PI3K, ERK, FAK, RICTOR, β-catenin and IGF-1. In addition, KPT-9274 and analogs suppressed the steady state level of NAD and ATP. Importantly, KPT-9274 given i.v. or orally at the maximum tolerated dose (140 mg/kg, once/day for 5 days/week for 4 weeks) dramatically inhibited the growth of QGP-1 and Bon-1 tumors. This is the first study demonstrating the role of PAK4 and NAMPT in pNETs. KPT-9274 is currently in a Phase I trial of patients with advance solid malignancies or NHL (NCT02702492). Our pre-clinical work establishes a solid rationale for a Phase II clinical study of KPT-9274 and an mTOR inhibitor combination for the treatment of difficult to treat pNETs.

Citation Format: Gabriel Mpilla, Irfana Muqbil, Amro Aboukameel, Philip A. Philip, William Senapedis, Erkan Baloglu, Yosef Landesman, Michael Kauffman, Sharon Shacham, Ramzi M. Mohammad, Asfar S. Azmi. PAK4-NAMPT dual inhibition as a feasible strategy for treatment of resistant pancreatic neuroendocrine tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4368.

Nuclear Export Inhibition for Pancreatic Cancer Therapy

Pancreatic cancer is a deadly disease that is resistant to most available therapeutics. Pancreatic cancer to date has no effective drugs that could enhance the survival of patients once their disease has metastasized. There is a need for the identification of novel actionable drug targets in this unusually recalcitrant cancer. Nuclear protein transport is an important mechanism that regulates the function of several tumor suppressor proteins (TSPs) in a compartmentalization-dependent manner. High expression of the nuclear exporter chromosome maintenance region 1 (CRM1) or exportin 1 (XPO1), a common feature of several cancers including pancreatic cancer, results in excessive export of critical TSPs to the incorrect cellular compartment, leading to their functional inactivation. Small molecule inhibitors of XPO1 can block this export, retaining very important and functional TSPs in the nucleus and leading to the effective killing of the cancer cells. This review highlights the current knowledge on the role of XPO1 in pancreatic cancer and how this serves as a unique and clinically viable target in this devastating and by far incurable cancer.

Vascular Endothelial Growth Factor (VEGF) Signaling in Tumour Vascularization: Potential and Challenges

Angiogenesis is defined as the physiological process by which new blood vessels develop from pre-existing vessels; either by sprouting or intussusception. Inhibition of angiogenesis is one of the most encouraging strategies to manage the growth and metastasis of cancers. The functional and proliferative status of blood vessels is regulated by the balance between various key molecules that either stimulate or inhibit angiogenesis. During quiescence, the "angiogenic switch" is "off". However, during tumour development pro-angiogenic factors such as vascular endothelial growth factor (VEGF), basic and acidic fibroblast growth factor, tumour necrosis factor-α and interleukin-1 are pathologically enhanced. Persistent growth of tumour directed capillary networks creates a favourable microenvironment, promoting cancer growth, progression and metastasis. VEGF, particularly VEGF-A, is a key angiogenic factor. Targeting VEGF, its receptors and the downstream signaling cascade, is a viable strategy to prevent tumour growth and metastasis. The present review discusses the role of VEGF in tumour angiogenesis and the current understanding of anti-VEGF therapies as well as refractoriness of anti-angiogenesis cancer therapy.

Targeting ERK enhances the cytotoxic effect of the novel PI3K and mTOR dual inhibitor VS-5584 in preclinical models of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease in urgent need of newer therapeutic modalities. Majority of patients with PDAC have mutations in KRAS, which unfortunately remains an ineffectual target. Our strategy here is to target KRAS downstream effectors PI3K and mTOR. In this study, we investigated the antitumor efficacy of the novel PI3K and mTOR dual inhibitor VS-5584 in PDAC. Our data shows that PI3K/mTOR dual inhibition causes ERK activation in all tested PDAC cell lines. Although the MEK inhibitor GSK1120212 could abrogate VS-5584-induced ERK activation, it did not substantially enhance cell death in all the cell lines tested. However, combination with ERK inhibitor SCH772984 not only mitigated VS-5584-induced ERK activation but also enhanced VS-5584-induced cell death. In a xenograft model of PDAC, we observed 28% and 44% tumor inhibition for individual treatment with VS-5584 and SCH772984, respectively, while the combined treatment showed superior tumor inhibition (80%) compared to vehicle control treatment. Our findings support the clinical development of VS-5584 and ERK inhibitor combination for PDAC treatment.

Dysregulated expression of SKP2 and its role in hematological malignancies

S-phase kinase-associated protein 2 (SKP2) is a well-studied F-box protein and a critical part of the Skp1-Cul1-Fbox (SCF) E3 ligase complex. It controls cell cycle by regulating the expression level of p27 and p21 through ubiquitination and proteasomal degradation. SKP2-mediated loss of p27Kip1 is associated with poor clinical outcome in various types of cancers including hematological malignancies. It is however well established that SKP2 is an oncogene, and its targeting may be an attractive therapeutic strategy for the management of hematological malignancies. In this article, we have highlighted the recent findings from our group and other investigators regarding the role of SKP2 in the pathogenesis of hematological malignancies.

Exportin 1 (XPO1) inhibition leads to restoration of tumor suppressor miR-145 and consequent suppression of pancreatic cancer cell proliferation and migration

Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer related deaths in the United States with a majority of these patients dying from aggressively invasive and metastatic disease. There is growing evidence that suggests an important role for microRNAs (miRNAs) in the pathobiology of aggressive PDAC. In this study, we found that the expression of miR-145 was significantly lower in PDAC cells when compared to normal pancreatic duct epithelial cells. Here we show that inhibition of the nuclear exporter protein exportin 1 (XPO1; also known as chromosome maintenance region 1 [CRM1]) by siRNA knockdown or by the Selective Inhibitor of Nuclear Export (SINE) compound (KPT-330; selinexor) increases miR-145 expression in PDAC cells resulting in the decreased cell proliferation and migration capacities. A similar result was obtained with forced expression of miR-145 in PDAC cells. To this end, SINE compound treatment mediated the down-regulation of known miR-145 targets genes including EGFR, MMP1, MT-MMP, c-Myc, Pak4 and Sox-2. In addition, selinexor induced the expression of two important tumor suppressive miRNAs miR-34c and let-7d leading to the up-regulation of p21^WAF1. These results are the first to report that targeted inhibition of the nuclear export machinery could restore tumor suppressive miRNAs in PDAC that warrants further clinical investigations.

Targeting of X-linked inhibitor of apoptosis protein and PI3-kinase/AKT signaling by embelin suppresses growth of leukemic cells

The X-linked inhibitor of apoptosis (XIAP) is a viable molecular target for anticancer drugs that overcome apoptosis-resistance of malignant cells. XIAP is an inhibitor of apoptosis, mediating through its association with BIR3 domain of caspase 9. Embelin, a quinone derivative isolated from the Embelia ribes plant, has been shown to exhibit chemopreventive, anti-inflammatory, and apoptotic activities via inhibiting XIAP activity. In this study, we found that embelin causes a dose-dependent suppression of proliferation in leukemic cell lines K562 and U937. Embelin mediated inhibition of proliferation correlates with induction of apoptosis. Furthermore, embelin treatment causes loss of mitochondrial membrane potential and release of cytochrome c, resulting in subsequent activation of caspase-3 followed by polyadenosin-5’-diphosphate-ribose polymerase (PARP) cleavage. In addition, embelin treatment of leukemic cells results in a decrease of constitutive phosphorylations/activation level of AKT and downregulation of XIAP. Gene silencing of XIAP and AKT expression showed a link between XIAP expression and activated AKT in leukemic cells. Interestingly, targeting of XIAP and PI3-kinase/AKT signaling augmented inhibition of proliferation and induction of apoptosis in leukemic cells. Altogether these findings raise the possibility that embelin alone or in combination with inhibitors of PI3-kinase/AKT pathway may have therapeutic usage in leukemia and possibly other malignancies with up-regulated XIAP pathway.

Abstract 1358: p21 activated kinase 4 (pak4) as a novel therapeutic target for non-hodgkin's lymphoma

Objective: The p21-activated kinase 4 (PAK4) is a key downstream effector of the Rho GTPase family and is over-expressed in many different cancer types. PAK4 protein, by virtue of its ability to engage multiple ligands, regulates a repertoire of signaling pathways. A survey of non-Hodgkin’s lymphoma (NHL) cell lines shows that there is increase in PAK4 mRNA and/or protein expression when compared to normal peripheral lymphocytes (PBL). Considering PAK4 RNA interference suppresses lymphoma cell proliferation, these findings point to a novel role for PAK4 in promoting NHL cell growth. To this end we examined the impact of the newly developed PAK4 allosteric modulators (PAMs) on NHL proliferation both in vitro and in vivo.

Methods: WSU-FSCCL (representing follicular small cell cleaved lymphoma) and WSU-DLCL2 (diffused large B-cell lymphoma) were exposed to increasing concentrations of different PAM analogs (KPT-7523, KPT-7189, KPT-9037, KPT-9274, or KPT-7010 [inactive]) or the Pan-PAK inhibitor, PF-3758309, in the presence or absence of CHOP (used at IC25) for 72 hrs. Following combination treatment viability was evaluated using Trypan Blue, apoptosis was analyzed using 7AAD, tetrachrome staining, Annexin V FITC and cell cycle arrest was accessed by flow cytometry. Protein and mRNA expression changes were evaluated using immunoblotting and RT-PCR. The toxicity and efficacy of PAMs were evaluated in sub-cutaneous and disseminated xenograft models of NHL.

Results: As single agents, PAMs show anti-proliferative activity in vitro against NHL cell lines (IC50s for: WSU-FSCCL = 50 nM and WSU-DLCL2 = 250 nM) while sparing normal PBL (IC50s in μM range). There was a statistically significant dose-dependent difference in apoptosis induction in NHL cell lines treated with PAMs when compared to vehicle control. PAMs reduced total p-PAK4 and downstream signaling proteins involved in proliferation and apoptosis. In R-CHOP combination studies we observed enhanced viability suppression, increased apoptosis, and concurrent down-regulation of PAK4 signaling pathway proteins when compared to any single agent alone. The clinical compound, KPT-9274, is well tolerated and showed remarkable anti-tumor activity in WSU-DLCL2 sub-cutaneous xenograft in mice (p < 0.01 at 140 mg/kg/bid for 4 weeks with no loss in body weight). Residual tumors analysis showed suppression of PAK4 signaling pathways. Single agent and R-CHOP combination efficacy is currently being evaluated in subcutaneous and systemic WSU-FSCCL and in primary patient derived xenografts in mice.

Conclusions: This is the first study demonstrating a role for PAK4 in diffused large B-cell and follicular small cell cleaved NHL. Our data shows that inhibition of PAK4 could become a viable therapy for NHL either alone or in combination with R-CHOP. Our data is directly applicable to the current Phase 1 trial of KPT-9274 in patients with advanced solid malignancies or NHL.

Citation Format: Asfar S. Azmi, Amro Aboukameel, Irfana Muqbil, Yiwei Li, William Senapedis, Erkan Baloglu, Yosef Landesman, Michael Kauffman, Sharon Shacham, Ayad Al-Katib, Ramzi M. Mohammad. p21 activated kinase 4 (pak4) as a novel therapeutic target for non-hodgkin's lymphoma [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 1358. doi:10.1158/1538-7445.AM2017-1358

Abstract 464: Novel role of xpo1 in regulating MicroRNAs related to pancreatic ductal adenocarcinoma invasion and metastasis

Objective: There are no known reports on the role of exportin 1 (XPO1; also known as chromosome maintenance region 1 [CRM1]) in microRNA biology. In this study, we for the first time demonstrate that interfering with XPO1 machinery can influence miRNA signaling leading to suppression of pancreatic ductal adenocarcinoma (PDAC) proliferation, invasion and metastasis.

Methods: miRNA arrays (LCSciences, Houston, TX) were performed on total RNA samples from PDAC cell lines (HPAC, MiaPaCa-2, AsPc-1 and L3.6pl) and normal human pancreatic ductal epithelial (HPDE) cells. PDAC cells were treated with XPO1 inhibitor (Selinexor) or transfected with control siRNA, XPO1 siRNA (Santa Cruz), miR-control or miR-145 mimic (Applied biosystems) all at a final concentration of 20 nM using DharmaFact Transfection Reagent (Dharmacon, Lafayette. CO). The total RNA and total protein from treated or transfected cells were subjected to real-time PCR or immunoblot analysis in order to measure expression level of miR-145, let-7d, miR-34c, miR-320, miR-205, and miR-145 target or downstream genes including EGFR, MMP1, MT-MMP, c-Myc, Sox-2, and PAK4. The impact of XPO1 inhibitor Selinexor on PDAC growth, proliferation, invasion and migrations was also evaluated using MTT and scratch assay.

Results: In this study, we show that PDAC cells have significantly reduced expression of miR-145 when compared to normal pancreatic duct epithelial cells. Similarly, forced expression of miR-145 in PDAC cells inhibited cell proliferation and migration. Conversely, we demonstrate that RNAi of XPO1 by siRNA knockdown or chemical inhibition of XPO1 by selective inhibitor of nuclear export compound (Selinexor) restores miR-145 expression in PDAC cells ultimately leading to inhibition of cell proliferation and migration. In addition, we show that the inhibition of cell proliferation and migration by Selinexor is mediated through the down-regulation of known miR-145 signals including EGFR, MMP1, MT-MMP, c-Myc, PAK4 and Sox-2. Selinexor also induced the expression of two important tumor suppressive miRNAs, miR-34c and let-7d, leading to the up-regulation of p21WAF1. We also observed the down-regulation of oncomir mir-205.

Conclusions: These results are the first to show that targeted inhibition of the nuclear exporter protein XPO1 by RNAi or Selinexor could restore tumor suppressive miRs in PDAC.

Citation Format: Asfar S. Azmi, Yiwei Li, Irfana Muqbil, Amro Aboukameel, William Senapedis, Erkan Baloglu, Yosef Landesman, Michael Kauffman, Sharon Shacham, Philip A. Philip, Ramzi M. Mohammad. Novel role of xpo1 in regulating MicroRNAs related to pancreatic ductal adenocarcinoma invasion and metastasis [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 464. doi:10.1158/1538-7445.AM2017-464

Anticancer potential of sanguinarine for various human malignancies

Sanguinarine (Sang) - a benzophenanthridine alkaloid extracted from Sanguinaria canadensis - exhibits antioxidant, anti-inflammatory, proapoptotic and growth inhibitory activities on tumor cells of various cancer types as established by in vivo and in vitro studies. Although the underlying mechanism of Sang antitumor activity is yet to be fully elucidated, Sang has displayed multiple biological effects, which remain to suggest its possible use in plant-derived treatments of human malignancies. This review covers the anticancer abilities of Sang including inhibition of aberrantly activated signal transduction pathways, induction of cell death and inhibition of cancer cell proliferation. It also highlights Sang-mediated inhibition of angiogenesis, inducing the expression of tumor suppressors, sensitization of cancer cells to standard chemotherapeutics to enhance their cytotoxic effects, while addressing the present need for further pharmacokinetic-based studies.

The Molecular Genetics of Autosomal Recessive Nonsyndromic Intellectual Disability: a Mutational Continuum and Future Recommendations

Intellectual disability (ID) is a clinical manifestation of the central nervous system without any major dysmorphologies of the brain. Biologically it affects learning capabilities, memory, and cognitive functioning. The basic defining features of ID are characterized by IQ<70, age of onset before 18 years, and impairment of at least two of the adaptive skills. Clinically it is classified in a syndromic (with additional abnormalities) and a nonsyndromic form (with only cognitive impairment). The study of nonsyndromic intellectual disability (NSID) can best explain the pathophysiology of cognition, intelligence and memory. Genetic analysis in autosomal recessive nonsyndrmic ID (ARNSID) has mapped 51 disease loci, 34 of which have revealed their defective genes. These genes play diverse physiological roles in various molecular processes, including methylation, proteolysis, glycosylation, signal transduction, transcription regulation, lipid metabolism, ion homeostasis, tRNA modification, ubiquitination and neuromorphogenesis. High-density SNP array and whole exome sequencing has increased the pace of gene discoveries and many new mutations are being published every month. The lack of uniform criteria has assigned multiple identifiers (or accession numbers) to the same MRT locus (e.g. MRT7 and MRT22). Here in this review we describe the molecular genetics of ARNSID, prioritize the candidate genes in uncharacterized loci, and propose a new nomenclature to reorganize the mutation data that will avoid the confusion of assigning duplicate accession numbers to the same ID locus and to make the data manageable in the future as well.

Potential therapeutic targets of Guggulsterone in cancer

Natural compounds capable of inducing apoptosis in cancer cells have always been of considerable interest as potential anti-cancer agents. Many such compounds are under screening and development with their potential evolution as a clinical drug benefiting many of the cancer patients. Guggulsterone (GS), a phytosterol isolated gum resin of the tree Commiphora mukul has been widely used in Indian traditional medicine as a remedy for various diseses. GS has been shown to possess cancer chemopreventive and therapeutic potential as established by in vitro and in vivo studies. GS has been shown to target constitutively activated survival pathways such as PI3-kinase/AKT, JAK/STAT, and NFκB signaling pathways that are involved in the regulation of growth and inflammatory responses via regulation of antiapoptotic and inflammatory genes. The current review focuses on the molecular targets of GS, cellular responses, and the animal model studies in various cancers. The mechanistic action of GS in different types of cancers also forms a part of this review. The perspective of translating this natural compound into a clinically approved drug with its pros and cons is also discussed.

Targeting acute myeloid leukemia stem cell signaling by natural products

Acute myeloid leukemia (AML) is the most commonly diagnosed leukemia in adults (25%) and comprises 15-20% in children. It is a genetically heterogeneous aggressive disease characterized by the accumulation of somatically acquired genetic changes, altering self-renewal, proliferation, and differentiation of hematopoietic progenitor cells, resulting in uncontrolled clonal proliferation of malignant progenitor myeloid cells in the bone marrow, peripheral blood, and occasionally in other body tissues. Treatment with modern chemotherapy regimen (cytarabine and daunorubicin) usually achieves high remission rates, still majority of patients are found to relapse, resulting in only 40-45% overall 5 year survival in young patients and less than 10% in the elderly AML patients. The leukemia stem cells (LSCs) are characterized by their unlimited self-renewal, repopulating potential and long residence in a quiescent state of G0/G1 phase. LSCs are considered to have a pivotal role in the relapse and refractory of AML. Therefore, new therapeutic strategies to target LSCs with limited toxicity towards the normal hematopoietic population is critical for the ultimate curing of AML. Ongoing research works with natural products like parthenolide (a natural plant extract derived compound) and its derivatives, that have the ability to target multiple pathways that regulate the self-renewal, growth and survival of LSCs point to ways for a possible complete remission in AML. In this review article, we will update and discuss various natural products that can target LSCs in AML.

Novel p21-Activated Kinase 4 (PAK4) Allosteric Modulators Overcome Drug Resistance and Stemness in Pancreatic Ductal Adenocarcinoma

The p21-activated kinase 4 (PAK4) is a key downstream effector of the Rho family GTPases and is found to be overexpressed in pancreatic ductal adenocarcinoma (PDAC) cells but not in normal human pancreatic ductal epithelia (HPDE). Gene copy number amplification studies in PDAC patient cohorts confirmed PAK4 amplification making it an attractive therapeutic target in PDAC. We investigated the antitumor activity of novel PAK4 allosteric modulators (PAM) on a panel of PDAC cell lines and chemotherapy-resistant flow-sorted PDAC cancer stem cells (CSC). The toxicity and efficacy of PAMs were evaluated in multiple subcutaneous mouse models of PDAC. PAMs (KPT-7523, KPT-7189, KPT-8752, KPT-9307, and KPT-9274) show antiproliferative activity in vitro against different PDAC cell lines while sparing normal HPDE. Cell growth inhibition was concurrent with apoptosis induction and suppression of colony formation in PDAC. PAMs inhibited proliferation and antiapoptotic signals downstream of PAK4. Co-immunoprecipitation experiments showed disruption of PAK4 complexes containing vimentin. PAMs disrupted CSC spheroid formation through suppression of PAK4. Moreover, PAMs synergize with gemcitabine and oxaliplatin in vitro KPT-9274, currently in a phase I clinical trial (clinicaltrials.gov; NCT02702492), possesses desirable pharmacokinetic properties and is well tolerated in mice with the absence of any signs of toxicity when 200 mg/kg daily is administered either intravenously or orally. KPT-9274 as a single agent showed remarkable antitumor activity in subcutaneous xenograft models of PDAC cell lines and CSCs. These proof-of-concept studies demonstrated the antiproliferative effects of novel PAMs in PDAC and warrant further clinical investigations. Mol Cancer Ther; 16(1); 76-87. ©2016 AACR.

Anti-tumor activity of selective inhibitor of nuclear export (SINE) compounds, is enhanced in non-Hodgkin lymphoma through combination with mTOR inhibitor and dexamethasone

In previous studies we demonstrated that targeting the nuclear exporter protein exportin-1 (CRM1/XPO1) by a selective inhibitor of nuclear export (SINE) compound is a viable therapeutic strategy against Non-Hodgkin Lymphoma (NHL). Our studies along with pre-clinical work from others led to the evaluation of the lead SINE compound, selinexor, in a phase 1 trial in patients with CLL or NHL (NCT02303392). Continuing our previous work, we studied combinations of selinexor-dexamethasone (DEX) and selinexor-everolimus (EVER) in NHL. Combination of selinexor with DEX or EVER resulted in enhanced cytotoxicity in WSU-DLCL2 and WSU-FSCCL cells which was consistent with enhanced apoptosis. Molecular analysis showed enhancement in the activation of apoptotic signaling and down-regulation of XPO1. This enhancement is consistent with the mechanism of action of these drugs in that both selinexor and DEX antagonize NF-κB (p65) and mTOR (EVER target) is an XPO1 cargo protein. SINE compounds, KPT-251 and KPT-276, showed activities similar to CHOP (cyclophosphamide-hydroxydaunorubicin-oncovin-prednisone) regimen in subcutaneous and disseminated NHL xenograft models in vivo. In both animal models the anti-lymphoma activity of selinexor is enhanced through combination with DEX or EVER. The in vivo activity of selinexor and related SINE compounds relative to 'standard of care' treatment is consistent with the objective responses observed in Phase I NHL patients treated with selinexor. Our pre-clinical data provide a rational basis for testing these combinations in Phase II NHL trials.

Abstract B38: Clinical translation of nuclear export inhibitor in metastatic pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) remains a deadly disease in urgent need of newer therapeutic modalities. PDAC tumors are very heterogeneous and carry alterations in many critical pathways rendering the design of therapy against a single pathway unrealistic. The disease requires a broad form of therapy that can target the activation of multiple tumor suppressor proteins (TSPs) simultaneously. We have shown that over-expression of the nuclear exporter protein CRM1 in PDAC leads to functional inactivation of TSPs (such as FOXO3a, p27, Par-4 and p53) through their mislocalization to the cytoplasmic compartment. We clearly demonstrated that targeted inhibition of CRM1 by CRISPR/Cas9 validated Specific Inhibitor of Nuclear Export (SINE) KPT-330/Selinexor can restore the function of multiple TSPs leading to PDAC cell death and tumor inhibition in orthotopic models. More significantly, our findings show that SINE synergize with gemcitabine (GEM) and nab-paclitaxel leading to enhanced PDAC growth inhibition, apoptosis, and spheroid disintegration of PDAC derived cancer stem cells (CSCs) that undergo epithelial-to-mesenchymal transition (EMT). The observed synergy was due in part to enhanced nuclear localization of TSPs and suppression of CSC markers alongside reversal of EMT markers. RNA from quadruplet combination treatment samples were subjected to Agilent HT12 microarrays and differentially expressed genes (p&lt;0.01) were subjected to pathway analysis. Our computational analysis demonstrated reversal of immune suppressive networks and suppression of CSC sustaining networks. Most importantly we observed activation of fibroblast specific cell death pathways highlighting an as of yet unexplored role of CRM1 in sustaining fibroblast growth that is recognized to support high desmoplastic reaction (DR) in PDAC. Our multi-model pre-clinical work has led to the approval of a Phase Ib/II clinical study involving GEM-nab-paclitaxel-Selinexor for metastatic PDAC (NCT02178436).

Citation Format: Asfar S. Azmi, Irfana Muqbil, Amro Aboukameel, Michael Kauffman, Sharon Shacham, Ramzi M. Mohammad, Philip A. Philip.{Authors}. Clinical translation of nuclear export inhibitor in metastatic pancreatic cancer. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr B38.