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PDF file, 71KB, The data are scaled by the positive control (1�M MG132) and the negative control (DMSO). The percentage of maximum activity (Amax) is represented in function of the crossing point (concentration in �M at 50% of MG132 activity). Each data point represents a cell line; the vertical and horizontal lines represent, respectively, the median of the crossing point values (1.33�M) and the median of the Amax values (-90.06%), of BKM120 across all cell lines. The populations of cell lines least responding to GDC-0941, among which some are sensitive to BKM120, are highlighted in green.

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PDF - 60K, Linear correlation observed between tumor growth inhibition (% T/C) or tumor regression and the fraction of time over the in vivo S473P-Akt IC80 in different cancer cell line-derived tumor xenografts implanted in nude mice (represented as dots) and nude rats (represented as triangles) following NVP-BYL719 treatment (R2=0.77, p

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Somatic PIK3CA mutations are frequently found in solid tumors, raising the hypothesis that selective inhibition of PI3Kα may have robust efficacy in PIK3CA-mutant cancers while sparing patients the side-effects associated with broader inhibition of the class I phosphoinositide 3-kinase (PI3K) family. Here, we report the biologic properties of the 2-aminothiazole derivative NVP-BYL719, a selective inhibitor of PI3Kα and its most common oncogenic mutant forms. The compound selectivity combined with excellent drug-like properties translates to dose- and time-dependent inhibition of PI3Kα signaling in vivo, resulting in robust therapeutic efficacy and tolerability in PIK3CA-dependent tumors. Novel targeted therapeutics such as NVP-BYL719, designed to modulate aberrant functions elicited by cancer-specific genetic alterations upon which the disease depends, require well-defined patient stratification strategies in order to maximize their therapeutic impact and benefit for the patients. Here, we also describe the application of the Cancer Cell Line Encyclopedia as a preclinical platform to refine the patient stratification strategy for NVP-BYL719 and found that PIK3CA mutation was the foremost positive predictor of sensitivity while revealing additional positive and negative associations such as PIK3CA amplification and PTEN mutation, respectively. These patient selection determinants are being assayed in the ongoing NVP-BYL719 clinical trials. Mol Cancer Ther; 13(5); 1117–29. ©2014 AACR.

PDF file, 300KB, A. Upon infection with viral particles obtained from the pBabe-puro-myr-Akt retroviral vectors, pools were selected upon addition of puromycin and maintained in culture for several weeks. Extracts from pools were generated for the indicated time of culture and analyzed by Western-blot for the expression of the exogenously expressed HA-tagged form of the dominant active myr-Akt protein. B. 2.5x106 MCF7-BP (upper panel) or MCF7-myr-Akt (bottom panel) were seeded in 10 cm dishes and exposed for 1 h to the indicated compounds at the indicated concentrations (in nM). Cells were then lyzed and cell extracts were analyzed by Western-blot for pathway inhibition as revealed by S473P-Akt levels.

The pan-phosphoinositide 3-kinase (PI3K) inhibitor BKM120 was found, at high concentrations, to cause cell death in various cellular systems, irrespective of their level of PI3K addiction. Transcriptional and biochemical profiling studies were used to identify the origin of these unexpected and apparently PI3K-independent effects. At 5- to 10-fold, the concentration needed to half-maximally inhibit PI3K signaling. BKM120 treatment caused changes in expression of mitotic genes and the induction of a robust G2–M arrest. Tubulin polymerization assays and nuclear magnetic resonance-binding studies revealed that BKM120 inhibited microtubule dynamics upon direct binding to tubulin. To assess the contribution of this off-target activity vis-à-vis the antitumor activity of BKM120 in PI3K-dependent tumors, we used a mechanistic PI3K-α–dependent model. We observed that, in vivo, daily treatment of mice with doses of BKM120 up to 40 mg/kg led to tumor regressions with no increase in the mitotic index. Thus, strong antitumor activity can be achieved in PI3K-dependent models at exposures that are below those necessary to engage the off-target activity. In comparison, the clinical data indicate that it is unlikely that BKM120 will achieve exposures sufficient to significantly engage the off-target activity at tolerated doses and schedules. However, in preclinical settings, the consequences of the off-target activity start to manifest themselves at concentrations above 1 μmol/L in vitro and doses above 50 mg/kg in efficacy studies using subcutaneous tumor–bearing mice. Hence, careful concentration and dose range selection is required to ensure that any observation can be correctly attributed to BKM120 inhibition of PI3K. Mol Cancer Ther; 11(8); 1747–57. ©2012 AACR.

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PDF file, 53KB, A and B. 5x105 A2058 cells were seeded in 10 cm dishes and incubated for 24 h either with increasing amounts of BKM120 (A) or with 5 �M of either GDC-0941 (B, top panel) or BEZ235 (B, bottom panel). Cells were then fixed, prepared as described for quantification of the population in the different phases of the cell cycle by fluorescence-activated cell sorting. G1, S and G2/M distribution for control untreated cells are described in the mean text and in Figure 4A. The activities of BKM120 on the cell cycle were plotted along to the inhibitory effects on pAkt levels (A).

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PDF - 129K, Legends for Supplementary Figures 1 through 4 and Supplementary Tables 1 through 7. Supplementary Table 1. Determination of NVP-BYL719 in vitro effects on human protein kinases. Supplementary Table 2. Activity profile of NVP-BYL719 in the Invitrogen Kinase panel. Supplementary Table 3. Activity profile of NVP-BYL719 in the Ambit Kinase panel. Supplementary Table 4. NVP-BYL719 Kd (nmol/L) determination in the Ambit Kinase panel for the hits found to be inhibited >90%. Supplementary Table 5. NVP-BYL719 anti-tumor effects in diverse cancer cell line-derived xenograft models. Supplementary Table 6. CCLE cell lines responsive to NVP-BYL719. Supplementary Table 7 Anti-tumor effect of NVP-BYL719 in patient-derived xenograft models carrying PIK3CA genetic alterations.

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PDF file, 107KB, A. 2.5x106 Rat1-myr-p110a (left) or U87MG cells were seeded in 10 cm dishes and exposed for 6h either to BKM120 (5 �M) or to the DMSO control. Cells were then lyzed and cell extracts were analyzed by Western-blot for PI3K pathway inhibition and G2/M markers as revealed by S473P-Akt (upper panel) and Ser10P-Histone H3 (bottom panel) levels, respectively. B. U87MG tumor bearing mice were treated orally, once per day for 6 days with BKM120 at the indicated doses. Tumor volumes were callipered and plotted. ns: not significant.

PDF file, 113KB, A. Effects of Paclitaxel and Nocodazole on Tubulin polymerization. Tubulin was mixed with either Paclitaxel (10 �M), Nocodazole (10 �M) or the DMSO control in the presence of GTP. The polymerization of monomeric tubulin into microtubule was started by transferring the reaction tubes from 4{degree sign}C to 37{degree sign}C, and monitored by the increase in absorbance (λ=340 nM) over a period of 60 min. B. Competition experiments of NVP-BKM120 with colchicine and podophyllotoxin by NMR spectroscopy. T1ρ relaxation of BKM120 in the presence of tubulin (50-fold excess of compound) remains unchanged after adding podophyllotoxin or colchicine, as emphasized by the drawn arrows. The spectra of the three compounds are shown in three colors at the bottom. C. Structures of GDC0941, BEZ235, Nocodazole and BKM120.

PDF - 71K, Rat1-myr-p110alpha (blue), beta (green) or delta (red) cells were treated with increasing concentrations of NVP-BYL719 for 30 minutes. Levels of S473P-Akt in cell extracts were quantified by Reverse Phase Protein Array as described in (18) and plotted as percentage of untreated control cells. The graph illustrates n=3 independent experiments. IC50s (plus/minus) SD and IC80s (plus/minus) SD of n=3 independent experiments are reported..

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PDF file, 653KB, MDA-MB231 (left) and U87MG (right) cells grown on coverslips were treated for 24 h either with BKM120 (5 μM) or Nocodazole (100 nM) and the effects of compound treatment on microtubule dynamics and G2/M arrest was monitored by immuno-fluorescence staining of alpha-tubulin (microtubules), gamma tubulin (centrosomes) and DAPI (DNA). Pictures were taken with a 100X objective.

PDF file, 2791KB. A2058 (upper panels), MDA-MB231 (lower panels) and U87MG cells grown on coverslips were treated for 6 h, 6 h with a subsequent 18 h washout period or 24 h with either 5 μM BKM120 or 100 nM Nocodazole and the effects of compound treatment on microtubule dynamics and G2/M arrest was monitored by immuno-fluorescence staining of alpha-tubulin. Pictures were taken with a 40X objective.

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PDF - 92K, NVP-BYL719 does not inhibit mTOR and PIKKs involved in DNA damage-repair processes. A. TSC1 -/- MEFs cells were grown in a 96-well format and treated for 1 h with increased concentrations of RAD001 or NVP-BYL719 (from 0.5 nmol/L to 10 ?mol/L in 1 third dilution steps) and immediately fixed. S235/236P-RPS6 levels were measured and IC50 determined with the Excel module XLfit. Background (no primary Ab incubated); BL, Baseline. B: TSC1 -/- MEFs cells were treated with increasing concentrations of NVP-BYL719 as indicated or RAD001 at 500 nmol/L or an equivalent DMSO concentration for 30 minutes. Levels of S235/236P-RPS6 and total RPS6 in protein- normalized lysates were detected by Western blot analyzis using an activation-state specific antibody, followed by incubation with species- specific HRP-labeled secondary antibody and signal development by ECL. C: 24 h post seeding, A549 cells were treated at the same time with Actinomycin D (Act D) at a concentration of 5 ?mol/L (an agent used to induce DNA damage), and with increasing concentrations of NVP-BYL719 as indicated or with the vehicle control (DMSO) for 1 h. Levels of S15P-p53 and tubulin in protein-normalized lysates were detected by Western blot analysis using an activation-state specific antibody, followed by incubation with species- specific HRP-labeled secondary antibody and signal development by ECL. D: 24 h post seeding, U2OS cells were pre-treated for 1 h with increased concentrations of NVP-BYL719 or KU55933 a specific small molecular mass inhibitor of ATM (Supplementary reference 1) at a concentration of 10 ?mol/L or with the vehicle control (DMSO). The cells were then irradiated with 15 Gy and re-incubated at 37 degrees C for 1 h and then lysed. Levels of S1981P-ATM in protein- normalized lysates were detected by Western blot analysis using an activation-state specific antibody, followed by incubation with species- specific HRP-labeled secondary antibody and signal development by ECL.

PDF - 37K, NVP-BYL719 was tested at 10 different concentrations (from 0.5 nmol/L to 10 μmol/L in 1 third dilution steps) against CLK2 (A) and LRRK2 (B). SelectScreenTM Kinase Profiling Service uses XLfit from IDBS to determine the IC50 values (IC50 CLK2=621 nmol/L; IC50 LRRK2=3'220 nmol/L). The dose response curve is curve fit to model number 205 (sigmoidal dose-response model).

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Purpose: PIM kinases have been shown to act as oncogenes in mice, with each family member being able to drive progression of hematologic cancers. Consistent with this, we found that PIMs are highly expressed in human hematologic cancers and show that each isoform has a distinct expression pattern among disease subtypes. This suggests that inhibitors of all three PIMs would be effective in treating multiple hematologic malignancies.Experimental Design: Pan-PIM inhibitors have proven difficult to develop because PIM2 has a low Km for ATP and, thus, requires a very potent inhibitor to effectively block the kinase activity at the ATP levels in cells. We developed a potent and specific pan-PIM inhibitor, LGB321, which is active on PIM2 in the cellular context.Results: LGB321 is active on PIM2-dependent multiple myeloma cell lines, where it inhibits proliferation, mTOR-C1 signaling and phosphorylation of BAD. Broad cancer cell line profiling of LGB321 demonstrates limited activity in cell lines derived from solid tumors. In contrast, significant activity in cell lines derived from diverse hematological lineages was observed, including acute lymphoblastic leukemia (ALL), acute myelogenous leukemia (AML), multiple myeloma and non-Hodgkin lymphoma (NHL). Furthermore, we demonstrate LGB321 activity in the KG-1 AML xenograft model, in which modulation of pharmacodynamics markers is predictive of efficacy. Finally, we demonstrate that LGB321 synergizes with cytarabine in this model.Conclusions: We have developed a potent and selective pan-PIM inhibitor with single-agent antiproliferative activity and show that it synergizes with cytarabine in an AML xenograft model. Our results strongly support the development of Pan-PIM inhibitors to treat hematologic malignancies. Clin Cancer Res; 20(7); 1834–45. ©2014 AACR.

PDF file - 346KB, Supplementary Figure 1. Normal vs. Tumor expression of PIM kinases mRNA across 17 tissue types. Supplementary Figure 2. Comparison of LGB321 on-target activity vs. Previously described pan-PIM inhibitor. Supplementary Figure 3. KINOMESCANTM of 1 mu M LGB321. Supplementary Figure 4. Biochemical and cellular selectivity of the LGB321 PIM inhibitor series towards GSK3 beta. Supplementary Figure 5. LGB321 does not inhibit EGFR signaling in HCC1954 cells. Supplementary Table 1. Sensitivity to LGB321 and Erlotinib of Lung Cells in the CCLE. Supplementary Table 2. Sensitivity to LGB321 of hematological malignacies cell lines.

Supplementary Fig from Identification and characterization of NVP-BEZ235, a new orally available dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor with potent in vivo antitumor activity

Supplementary Material from Identification and characterization of NVP-BEZ235, a new orally available dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor with potent in vivo antitumor activity

The phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin inhibitor (mTOR) pathway is often constitutively activated in human tumor cells, providing unique opportunities for anticancer therapeutic intervention. NVP-BEZ235 is an imidazo[4,5-c]quinoline derivative that inhibits PI3K and mTOR kinase activity by binding to the ATP-binding cleft of these enzymes. In cellular settings using human tumor cell lines, this molecule is able to effectively and specifically block the dysfunctional activation of the PI3K pathway, inducing G1 arrest. The cellular activity of NVP-BEZ235 translates well in in vivo models of human cancer. Thus, the compound was well tolerated, displayed disease stasis when administered orally, and enhanced the efficacy of other anticancer agents when used in in vivo combination studies. Ex vivo pharmacokinetic/pharmacodynamic analyses of tumor tissues showed a time-dependent correlation between compound concentration and PI3K/Akt pathway inhibition. Collectively, the preclinical data show that NVP-BEZ235 is a potent dual PI3K/mTOR modulator with favorable pharmaceutical properties. NVP-BEZ235 is currently in phase I clinical trials. [Mol Cancer Ther 2008;7(7):1–13 [Mol Cancer Ther 2008;7(7):1851–13]

Pan proviral insertion site of Moloney murine leukemia (PIM) 1, 2, and 3 kinase inhibitors have recently begun to be tested in humans to assess whether pan PIM kinase inhibition may provide benefit to cancer patients. Herein, the synthesis, in vitro activity, in vivo activity in an acute myeloid leukemia xenograft model, and preclinical profile of the potent and selective pan PIM kinase inhibitor compound 8 (PIM447) are described. Starting from the reported aminopiperidyl pan PIM kinase inhibitor compound 3, a strategy to improve the microsomal stability was pursued resulting in the identification of potent aminocyclohexyl pan PIM inhibitors with high metabolic stability. From this aminocyclohexyl series, compound 8 entered the clinic in 2012 in multiple myeloma patients and is currently in several phase 1 trials of cancer patients with hematological malignancies.

The genes encoding RAS family members are frequently mutated in juvenile myelomonocytic leukemia (JMML) and acute myeloid leukemia (AML). RAS proteins are difficult to target pharmacologically; therefore, targeting the downstream PI3K and RAF/MEK/ERK pathways represents a promising approach to treat RAS-addicted tumors. The p110α isoform of PI3K (encoded by Pik3ca) is an essential effector of oncogenic KRAS in murine lung tumors, but it is unknown whether p110α contributes to leukemia. To specifically examine the role of p110α in murine hematopoiesis and in leukemia, we conditionally deleted p110α in HSCs using the Cre-loxP system. Postnatal deletion of p110α resulted in mild anemia without affecting HSC self-renewal; however, deletion of p110α in mice with KRASG12D-associated JMML markedly delayed their death. Furthermore, the p110α-selective inhibitor BYL719 inhibited growth factor-independent KRASG12D BM colony formation and sensitized cells to a low dose of the MEK inhibitor MEK162. Furthermore, combined inhibition of p110α and MEK effectively reduced proliferation of RAS-mutated AML cell lines and disease in an AML murine xenograft model. Together, our data indicate that RAS-mutated myeloid leukemias are dependent on the PI3K isoform p110α, and combined pharmacologic inhibition of p110α and MEK could be an effective therapeutic strategy for JMML and AML.

A novel, previously undescribed 4H-thiazolo[5',4':4,5]pyrano[2,3-c]pyridine tricyclic scaffold has been discovered. The application of this novel chemotype leading to a potent and selective prototype PI3Kα inhibitor with favorable physicochemical and PK-properties is described.

Following the discovery of NVP-BEZ235, our first dual pan-PI3K/mTOR clinical compound, we sought to identify additional phosphoinositide 3-kinase (PI3K) inhibitors from different chemical classes with a different selectivity profile. The key to achieve these objectives was to couple a structure-based design approach with intensive pharmacologic evaluation of selected compounds during the medicinal chemistry optimization process. Here, we report on the biologic characterization of the 2-morpholino pyrimidine derivative pan-PI3K inhibitor NVP-BKM120. This compound inhibits all four class I PI3K isoforms in biochemical assays with at least 50-fold selectivity against other protein kinases. The compound is also active against the most common somatic PI3Kα mutations but does not significantly inhibit the related class III (Vps34) and class IV (mTOR, DNA-PK) PI3K kinases. Consistent with its mechanism of action, NVP-BKM120 decreases the cellular levels of p-Akt in mechanistic models and relevant tumor cell lines, as well as downstream effectors in a concentration-dependent and pathway-specific manner. Tested in a panel of 353 cell lines, NVP-BKM120 exhibited preferential inhibition of tumor cells bearing PIK3CA mutations, in contrast to either KRAS or PTEN mutant models. NVP-BKM120 shows dose-dependent in vivo pharmacodynamic activity as measured by significant inhibition of p-Akt and tumor growth inhibition in mechanistic xenograft models. NVP-BKM120 behaves synergistically when combined with either targeted agents such as MEK or HER2 inhibitors or with cytotoxic agents such as docetaxel or temozolomide. The pharmacological, biologic, and preclinical safety profile of NVP-BKM120 supports its clinical development and the compound is undergoing phase II clinical trials in patients with cancer. Mol Cancer Ther; 11(2); 317–28. ©2011 AACR.

Over the past years, a key focus has been on identifying inhibitors against components of pathways that drive tumor cell proliferation, survival, and metastasis such as the PI3K/mTOR pathway, known to be implicated in many human cancers through various mechanisms, such as, somatic PIK3CA missense mutations that occur at high frequency in a number of common solid tumors including ~40% of ER+ breast cancer patients. Based on these findings, cancer-specific mutants of PI3Kα appear to be ideal targets for PI3Kα selective inhibitors such as alpelisib which is unique in its relative selectivity for the α-isoform and previously reported to be efficacious in PIK3CA mutant cancer models. Recently, using the ER-negative/HER2-positive/PIK3CA mutant HCC1954 breast cancer cell line, the PI3K β-sparing inhibitor taselisib has been described to have a dual mechanism of action, both blocking PI3K signaling and inducing a decrease in p110α protein levels. Here, we investigated whether such dual mechanism of action could be associated with PI3Kα selective inhibition in ER+/PIK3CA mutant breast cancer pre-clinical models specifically. In vitro, using the T47D ER+/PIK3CA mutant breast cancer cell line, alpelisib displays dual MoA by inhibiting p-Akt and inducing a decrease of p110a protein levels in a dose-dependent manner. This effect is observed upon 24 hours of compound treatment and is maintained for at least 96 hours upon treatment. Interestingly, for both alpelisib and taselisib, p110α degradation becomes more pronounced at concentrations which produce strong PI3K pathway inhibition (>80% p-Akt inhibition). In contrast to T47D cells, we do not observe p110α degradation upon 24 hours treatment in 4 additional ER+/PIK3CA mutant breast cancer cell lines tested, despite a dose-dependent and robust inhibition of the PI3K pathway, suggesting the effect might be specific to certain cell lines or restricted to certain PIK3CA mutations or might require longer compound treatment periods. In the EFM19 cells, the PI3K inhibition-mediated p110α degradation occurs upon minimum 48 hours treatment for both alpelisib and taselisib. In vitro, when alpelisib and taselisib are then compared at concentrations that equally inhibit the PI3K pathway and equally degrade p110α, both compounds display similar inhibitory effects on T47D and EFM19 cell proliferation and survival. In vivo, in an ER+/ PIK3CA mutant breast cancer patient derived xenograft (PTX) model, alpelisib and taselisib show comparable anti-tumoral efficacy when administered at doses that are equally well tolerated and induced comparable PI3K pathway modulation. Overall, the data demonstrate that in ER+/ PIK3CA mutant breast cancer pre-clinical models, selective PI3Kα inhibition can induce a dual mechanism of action and produces robust efficacy. Citation Format: Christine Fritsch, Estelle Pfister, Nicolas Ebel, Daniel Guthy, Christian Schnell, Francesco Hofmann. Determination of the PI3Kα selective inhibitor alpelisib mechanism of action and efficacy in ER+/ PIK3CA mutant breast cancer preclinical models [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 3934.

The gene encoding for the catalytic subunit of the phosphatidylinositol-3-kinase (PI3K), p110a (PIK3CA) is the most frequently mutated kinase in cancer. This discovery triggered the development of small molecule anti-PI3K inhibitors, such as NVP-BYL719. However, the PI3K / Akt signaling pathway plays not only an important role in promoting cell growth, proliferation and survival but also in regulating glucose homeostasis by directly mediating insulin-stimulated glucose uptake into insulin sensitive tissues (adipocytes and muscles). NVP-BYL719 (a selective inhibitor of the class Ia PI3K isoform alpha) given in the morning is facing on-target tolerability challenge (hyperglycemia) in clinical trials limiting the dose being administered to patient (1). As glucose metabolism is highly impacted by circadian rhythms in patients and rodents, we have decided to adopt an integrative circadian-timing approach in our pre-clinical models to interrogate the benefit of morning vs evening dosing for BYL719. By using a newly developed radio-telemetry technology (2), we were able to record in real time and 'around-the-clock' blood glucose levels in stress-free, freely moving rats dosed with NVP-BYL719 at different regimens. The dynamic profile of hyperglycemia observed after active or inactive period dosing of NVP-BYL719 (50 mg/kg qd p.o.) were similar. Dosing before the inactive phase (10 a.m.) allowed blood glucose to normalize in between 2 doses, which could not be achieved when dosing before the active phase (5 p.m.). After treatment discontinuation a significant hyperglycemia remained for a period up to 12h in the group dosed before the active phase (5 p.m.). Circadian “evening” NVP-BYL719 dosing is associated with a better control of glycaemia. Clinically this could potentially translate to better compliance and longer time on treatment hence better efficacy for patient. Based on these findings we could recommend optimized treatment schedules for future combination experiments in the clinic with NVP-BYL719. 1) Juric et al, “Phase I study of the PI3Kα Inhibitor BYL719, as a Single Agent in Patients with Advanced Solid Tumors (AST)”, Annals of Oncology (2014), 25 (Supp. 4) 2) Brockway et al, “Fully Implantable Arterial Blood Glucose Device for Metabolic Research Applications in Rats for Two Months”, J Diabetes Sci Technol (2015), 9(4):771-81 Citation Format: Christian R. Schnell, Thomas Ferrat, Daniel Wyss, Walter Tinetto, Sonja Tobler, Christine Fritsch, Michael Jensen. Circadian timing regimen for alpelisib (NVP-BYL719), a selective inhibitor of the class Ia PI3K isoform alpha to maximize therapeutic index [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 3933.

Pan proviral insertion site of Moloney murine leukemia (PIM) 1, 2, and 3 kinase inhibitors have recently begun to be tested in humans to assess whether pan PIM kinase inhibition may provide benefit to cancer patients. Herein, the synthesis, in vitro activity, in vivo activity in an acute myeloid leukemia xenograft model, and preclinical profile of the potent and selective pan PIM kinase inhibitor compound 8 (PIM447) are described. Starting from the reported aminopiperidyl pan PIM kinase inhibitor compound 3, a strategy to improve the microsomal stability was pursued resulting in the identification of potent aminocyclohexyl pan PIM inhibitors with high metabolic stability. From this aminocyclohexyl series, compound 8 entered the clinic in 2012 in multiple myeloma patients and is currently in several phase 1 trials of cancer patients with hematological malignancies.

A cyclisation within a 4',5-bisthiazole (S)-proline-amide-urea series of selective PI3Kα inhibitors led to a novel 4,5-dihydrobenzo[1,2-d:3,4-d]bisthiazole tricyclic sub-series. The synthesis and optimisation of this 4,5-dihydrobenzo[1,2-d:3,4-d]bisthiazole sub-series and the expansion to a related tricyclic 4,5-dihydrothiazolo[4,5-h]quinazoline sub-series are described. From this work analogues including 11, 12, 19 and 23 were identified as potent and selective PI3Kα inhibitor in vivo tool compounds.

Exploring the affinity-pocket binding moiety of a 2-aminothiazole (S)-proline-amide-urea series of selective PI3Kα inhibitors using a parallel-synthesis approach led to the identification of a novel 4',5-bisthiazole sub-series. The synthesis and optimisation of both the affinity pocket and (S)-proline amide moieties within this 4',5-bisthiazole sub-series are described. From this work a number of analogues, including 14 (A66) and 24, were identified as potent and selective PI3Kα inhibitor in vitro tool compounds.

Good visual acuity requires that the axial length of the ocular globe is matched to the refractive power of the cornea and lens to focus the images of distant objects onto the retina. During the growth of the juvenile eye, this is achieved through the emmetropization process that adjusts the ocular axial length to compensate for the refractive changes that occur in the anterior segment. A failure of the emmetropization process can result in either excessive or insufficient axial growth, leading to myopia or hyperopia, respectively. Emmetropization is mainly regulated by the retina, which generates two opposite signals: “GO/GROW” signals to increase axial growth and “STOP” signals to block it. The presence of GO/GROW and STOP signals was investigated by a proteomics analysis of the retinas from chicken with experimental myopia and hyperopia. Of 18 differentially expressed proteins that were identified, five displayed an expression profile corresponding to GO/GROW signals, and two corresponded to STOP signals. Western blotting confirmed that apolipoprotein A-I (apoA-I) has the characteristics of a STOP signal both in the retina as well as in the fibrous sclera. In accordance with this, intraocular application of the peroxisome proliferator-activated receptor agonist GW7647 resulted in up-regulation of apoA-I levels and in a significant reduction of experimental myopia. In conclusion, using a comprehensive functional proteomics analysis of chicken ocular growth models we identified targets for ocular growth control. The correlation of elevated apoA-I levels with reduced ocular axial growth points toward a functional relationship with the observed morphological changes of the eye. Molecular & Cellular Proteomics 5:2158–2166, 2006.

Following loss of functional small bowel surface area due to surgical resection, the remnant gut undergoes an adaptive response characterized by increased crypt cell proliferation and enhanced villus height and crypt depth, resulting in augmented intestinal nutrient absorptive capacity. Previous studies showed that expression of the immediate early gene tis7 is markedly up-regulated in intestinal enterocytes during the adaptive response. To study its role in the enterocyte, transgenic mice were generated that specifically overexpress TIS7 in the gut. Nucleotides -596 to +21 of the rat liver fatty acid-binding protein promoter were used to direct abundant overexpression of TIS7 into small intestinal upper crypt and villus enterocytes. TIS7 transgenic mice had increased total body adiposity and decreased lean muscle mass compared with normal littermates. Oxygen consumption levels, body weight, surface area, and small bowel weight were decreased. On a high fat diet, transgenic mice exhibited a more rapid and proportionately greater gain in body weight with persistently elevated total body adiposity and increased hepatic fat accumulation. Bolus fat feeding resulted in a greater increase in serum triglyceride levels and an accelerated appearance of enterocytic, lamina propria, and hepatic fat. Changes in fat homeostasis were linked to increased expression of genes involved in enterocytic triglyceride metabolism and changes in growth with decreased insulin-like growth factor-1 expression. Thus, TIS7 overexpression in the intestine altered growth, metabolic rate, adiposity, and intestinal triglyceride absorption. These results suggest that TIS7 is a unique mediator of nutrient absorptive and metabolic adaptation following gut resection.

The formation of the crypt-villus axis during gut ontogeny requires continued reciprocal interactions between the endoderm and mesenchyme. Epimorphin/syntaxin 2 (epimorphin) is a mesenchymal protein expressed in the fetal gastrointestinal tract during villus morphogenesis. To elucidate its role in gut ontogeny, the epimorphin cDNA was transfected, in sense and antisense orientations, into a rat intestinal myofibroblast cell line, MIC 216. To determine the effects of epimorphin on the epithelium, myofibroblasts were cocultured with the Caco2 cell line. Caco2 cells spread in a simple monolayer over antisense-transfected cells lacking epimorphin. In contrast, sense-transfected myofibroblasts induced Caco2 cells to form compact, round clusters with small lumens. These morphologic differences were preserved in Transwell cocultures in which cell-cell contact was prevented, suggesting that epimorphin's effects were mediated by secreted factor(s). To determine the effects of epimorphin on crypt-villus axis formation in an in vivo model, rat gut endoderm was combined with epimorphin-transfected myofibroblasts and implanted into the chick intracoelomic cavity. The grafts in which epimorphin was overexpressed revealed multiple well-formed villi with crypt-like units, whereas those in which epimorphin expression was inhibited developed into round cystic structures without crypts or villi. Of several potential secreted morphogens, only the expression of bone morphogenetic protein 4 (Bmp4) was increased in the epimorphin-transfected cells. Incubation with noggin partially blocked the transfected myofibroblasts' effects on Caco2 colony morphology. These results indicate that mesenchymal epimorphin has profound effects on crypt-villus morphogenesis, mediated in part by secreted factor(s) including the Bmp's.

Somatic PIK3CA mutations are frequently found in solid tumors, raising the hypothesis that selective inhibition of PI3Kα may have robust efficacy in PIK3CA-mutant cancers while sparing patients the side-effects associated with broader inhibition of the class I phosphoinositide 3-kinase (PI3K) family. Here, we report the biologic properties of the 2-aminothiazole derivative NVP-BYL719, a selective inhibitor of PI3Kα and its most common oncogenic mutant forms. The compound selectivity combined with excellent drug-like properties translates to dose- and time-dependent inhibition of PI3Kα signaling in vivo, resulting in robust therapeutic efficacy and tolerability in PIK3CA-dependent tumors. Novel targeted therapeutics such as NVP-BYL719, designed to modulate aberrant functions elicited by cancer-specific genetic alterations upon which the disease depends, require well-defined patient stratification strategies in order to maximize their therapeutic impact and benefit for the patients. Here, we also describe the application of the Cancer Cell Line Encyclopedia as a preclinical platform to refine the patient stratification strategy for NVP-BYL719 and found that PIK3CA mutation was the foremost positive predictor of sensitivity while revealing additional positive and negative associations such as PIK3CA amplification and PTEN mutation, respectively. These patient selection determinants are being assayed in the ongoing NVP-BYL719 clinical trials. Mol Cancer Ther; 13(5); 1117–29. ©2014 AACR.

Purpose: PIM kinases have been shown to act as oncogenes in mice, with each family member being able to drive progression of hematologic cancers. Consistent with this, we found that PIMs are highly expressed in human hematologic cancers and show that each isoform has a distinct expression pattern among disease subtypes. This suggests that inhibitors of all three PIMs would be effective in treating multiple hematologic malignancies. Experimental Design: Pan-PIM inhibitors have proven difficult to develop because PIM2 has a low Km for ATP and, thus, requires a very potent inhibitor to effectively block the kinase activity at the ATP levels in cells. We developed a potent and specific pan-PIM inhibitor, LGB321, which is active on PIM2 in the cellular context. Results: LGB321 is active on PIM2-dependent multiple myeloma cell lines, where it inhibits proliferation, mTOR-C1 signaling and phosphorylation of BAD. Broad cancer cell line profiling of LGB321 demonstrates limited activity in cell lines derived from solid tumors. In contrast, significant activity in cell lines derived from diverse hematological lineages was observed, including acute lymphoblastic leukemia (ALL), acute myelogenous leukemia (AML), multiple myeloma and non-Hodgkin lymphoma (NHL). Furthermore, we demonstrate LGB321 activity in the KG-1 AML xenograft model, in which modulation of pharmacodynamics markers is predictive of efficacy. Finally, we demonstrate that LGB321 synergizes with cytarabine in this model. Conclusions: We have developed a potent and selective pan-PIM inhibitor with single-agent antiproliferative activity and show that it synergizes with cytarabine in an AML xenograft model. Our results strongly support the development of Pan-PIM inhibitors to treat hematologic malignancies. Clin Cancer Res; 20(7); 1834–45. ©2014 AACR.

Laminin-5 is a trimer of laminin α3, β3 and γ2 chains that is found in the intestinal basement membrane. Deposition of the laminin γ2 chain at the basement membrane is of great interest because it undergoes a developmental shift in its cellular expression. Here we study the regulatory elements that control basal and cytokine-activated transcriptional expression of the LAMC2 gene, which encodes the laminin γ2 chain. By using transient transfection experiments we demonstrated the presence of constitutive and cytokine-responsive cis-elements. Comparison of the transcriptional activity of the LAMC2 promoter in the epithelial HT29mtx cells with that in small-intestinal fibroblastic cells (C20 cells) led us to conclude that two regions with constitutive epithelium-specific activity are present between positions -1.2 and -0.12 kb. This was further validated by transfections of primary foetal intestinal endoderm and mesenchyme. A 2.5 kb portion of the LAMC2 5ʹ flanking region was equally responsive to PMA and hepatocyte growth factor (HGF), whereas it was less responsive to transforming growth factor β1. A minimal promoter limited to the initial 120 bp upstream of the transcriptional start site maintained inducibility by PMA and HGF. This short promoter fragment contains two activator protein 1 (AP-1) elements and the 5ʹ-most of these is a composite AP-1/Sp1 element. The 5ʹAP-1 element is crucial to the HGF-mediated activity of the promoter; analysis of interacting nuclear proteins demonstrated that AP-1 proteins containing JunD mediate the response to HGF.

Oncogene activation by amplification and/or overexpression has been implicated in the development and progression of a number of malignancies. To better define the role of oncogene activation in adenocarcinomas arising in the setting of Barrett esophagus, we examined 44 resected Barrett adenocarcinomas for c-erb B-2, epidermal growth factor receptor (EGFR), c-myc, and cyclin DI gene amplification as well as c-erb B-2 and EGFR expression. DNA was extracted from formalin-fixed paraffin-embedded tissue and analyzed by differential polymerase chain reaction, a technique that permits semiquantitative analysis of gene dosage on archival material. Formalinfixed paraffin-embedded sections were stained with monoclonal antibodies directed against either the internal domain of c-erb B-2 or the extracellular domain of EGFR with a labeled streptavidin biotin technique. C-erb B-2 amplification was identified in three (7%) cases. A plasma membrane pattern of c-erb B-2 immunoreactivity in >50% of tumor cells correlated highly with c-erb B-2 amplification ( P=.00008). EGFR amplification was noted in 18% of cases and correlated highly with the intensity of EGFR immunoreactivity ( P=.0004). C-myc amplification was present in 18% of cases. No tumors showed cyclin DI amplification. Follow-up was available regarding 29 patients and showed decreased mean survival ( P=.029) in patients with strong EGFR immunoreactivity (5.8 months) versus those with weak or absent EGFR labeling (11.8 months), and a trend toward decreased one-year survival (P=.069) for patients with (17%) versus those without (52%) c-myc amplification. Our results indicate one or more selected oncogenes are amplified/overexpressed in some Barrett adenocarcinomas and that EGFR and c-erb B-2 overexpression correlates with amplification. Additionally, strong EGFR expression in tumor cells indicates a poorer prognosis.

Mantle cell lymphoma (MCL) is an aggressive malignancy that is characterized by poor prognosis. Large-scale pharmacological profiling across more than 100 hematological cell line models identified a subset of MCL cell lines that are highly sensitive to the B cell receptor (BCR) signaling inhibitors ibrutinib and sotrastaurin. Sensitive MCL models exhibited chronic activation of the BCR-driven classical nuclear factor-κB (NF-κB) pathway, whereas insensitive cell lines displayed activation of the alternative NF-κB pathway. Transcriptome sequencing revealed genetic lesions in alternative NF-κB pathway signaling components in ibrutinib-insensitive cell lines, and sequencing of 165 samples from patients with MCL identified recurrent mutations in TRAF2 or BIRC3 in 15% of these individuals. Although they are associated with insensitivity to ibrutinib, lesions in the alternative NF-κB pathway conferred dependence on the protein kinase NIK (also called mitogen-activated protein 3 kinase 14 or MAP3K14) both in vitro and in vivo. Thus, NIK is a new therapeutic target for MCL treatment, particularly for lymphomas that are refractory to BCR pathway inhibitors. Our findings reveal a pattern of mutually exclusive activation of the BCR-NF-κB or NIK-NF-κB pathways in MCL and provide critical insights into patient stratification strategies for NF-κB pathway-targeted agents.

Phosphatidylinositol-3-kinase α (PI3Kα) is a therapeutic target of high interest in anticancer drug research. On the basis of a binding model rationalizing the high selectivity and potency of a particular series of 2-aminothiazole compounds in inhibiting PI3Kα, a medicinal chemistry program has led to the discovery of the clinical candidate NVP-BYL719.

The pan-phosphoinositide 3-kinase (PI3K) inhibitor BKM120 was found, at high concentrations, to cause cell death in various cellular systems, irrespective of their level of PI3K addiction. Transcriptional and biochemical profiling studies were used to identify the origin of these unexpected and apparently PI3K-independent effects. At 5- to 10-fold, the concentration needed to half-maximally inhibit PI3K signaling. BKM120 treatment caused changes in expression of mitotic genes and the induction of a robust G2–M arrest. Tubulin polymerization assays and nuclear magnetic resonance-binding studies revealed that BKM120 inhibited microtubule dynamics upon direct binding to tubulin. To assess the contribution of this off-target activity vis-a-vis the antitumor activity of BKM120 in PI3K-dependent tumors, we used a mechanistic PI3K-α–dependent model. We observed that, in vivo , daily treatment of mice with doses of BKM120 up to 40 mg/kg led to tumor regressions with no increase in the mitotic index. Thus, strong antitumor activity can be achieved in PI3K-dependent models at exposures that are below those necessary to engage the off-target activity. In comparison, the clinical data indicate that it is unlikely that BKM120 will achieve exposures sufficient to significantly engage the off-target activity at tolerated doses and schedules. However, in preclinical settings, the consequences of the off-target activity start to manifest themselves at concentrations above 1 μmol/L in vitro and doses above 50 mg/kg in efficacy studies using subcutaneous tumor–bearing mice. Hence, careful concentration and dose range selection is required to ensure that any observation can be correctly attributed to BKM120 inhibition of PI3K. Mol Cancer Ther; 11(8); 1747–57. ©2012 AACR . This article is featured in Highlights of This Issue, [p. 1619][1] [1]: /lookup/volpage/11/1619?iss=8

The cyclin Dl gene, located on chromosome llql3, is frequently rea%anged in parathyroid neoplasms and amplified in some carcinomas of other organs. Recent studies have detected amplification of cyclin Dl and other markers on chromosome 1 lql3 (evaluated by Southern or slot blot assays) in ∼25–50% of

NVP-BEZ235 is a dual PI3K/mTOR inhibitor currently in phase I clinical trials. We profiled this compound against a panel of breast tumor cell lines to identify the patient populations that would benefit from such treatment. In this setting, NVP-BEZ235 selectively induced cell death in cell lines presenting either HER2 amplification and/or PIK3CA mutation, but not in cell lines with PTEN loss of function or KRAS mutations, for which resistance could be attributed, in part to ERK pathway activity. An in depth analysis of death markers revealed that the cell death observed upon NVP-BEZ235 treatment could be recapitulated with other PI3K inhibitors and that this event is linked to active PARP cleavage indicative of an apoptotic process. Moreover, the effect seemed to be partly independent of the caspase-9 executioner and mitochondrial activated caspases, suggesting an alternate route for apoptosis induction by PI3K inhibitors. Overall, this study will provide guidance for patient stratification for forthcoming breast cancer phase II trials for NVP-BEZ235.