Marked Tumor Research Articles

Ellagic Acid Enhances Apoptotic Sensitivity of Breast Cancer Cells to γ-Radiation

ABSTRACTHerbal polyphenols have gained increased significance because of the promises they hold in the prevention and treatment of cancer. There exists an enormous opportunity for the screening and valuation of natural dietary compounds in the development of an effective chemopreventive drug and radiosensitizer that may be of practical use for patients undergoing cancer therapy. This study describes the effect of the flavonoid ellagic acid (EA) on gamma-irradiated human breast cancer MCF-7 cells in vitro when administered alone or in combination with radiation. It was interesting to find the radioprotective effect of EA on NIH3T3, which is a normal cell line. Irradiation of breast tumor cells in the presence of EA (10 μM) to doses of 2 and 4-Gy gamma radiation produced a marked synergistic tumor cytotoxicity while it was found to aid recovery from the radiation damage to NIH3T3 cells. When cells were given a combined treatment of EA and radiation, the cell death increased to 21.7% and 20.7% in the 2 and 4-Gy-treated cells respectively, significantly (P < 0.05) reducing the capacity of MCF-7 cells to form colonies. Even at 24 h, 38 foci/cell were observed in samples that were given the combined treatment, suggesting the cells' inability in repairing the damage. Also, increased apoptosis in EA+ 2Gy (50%) and EA+ 4 Gy (62%)-treated cells was observed in the the sub-G1 phase of the cell cycle. A 6.2-fold decrease in the mitochondrial membrane potential was observed in the combined treatment of EA and IR that facilitated the upregulation of pro-apopttotic Bax and downregulation of Bcl-2, pushing the MCF-7 cells to undergo an apoptotic cell death. It is suggested that EA may be a potential drug adjuvant for improving cancer radiotherapy by increasing tumor toxicity and reducing the normal cell damage caused by irradiation.

TKI-addicted ROS1-rearranged cells are destined to survival or death by the intensity of ROS1 kinase activity

ROS1 rearrangement is observed in 1–2% of non-small cell lung cancers (NSCLC). The ROS1 tyrosine kinase inhibitor (TKI) crizotinib has induced marked tumour shrinkage in ROS1-rearranged cancers. However, emergence of acquired resistance to TKI is inevitable within a few years. Previous findings indicate that cabozantinib overcomes secondary mutation–mediated crizotinib-resistance in ROS1-fusion-positive cells. Here we attempted to establish cabozantinib-resistant cells by N-ethyl-N-nitrosourea mutagenesis screening using CD74-ROS1–expressing Ba/F3 cells. Two resistant cell lines with CD74-ROS1 F2004V or F2075C mutations, which are homologous to ALK F1174 or F1245 mutations, survived in the presence of a low dose of ROS1-TKI. Removal of ROS1-TKI from these TKI-addicted cells induced excessive activation of ROS1 tyrosine kinase followed by apoptosis. We succeeded in recapturing the TKI-addicted phenotype using doxycycline-inducible CD74-ROS1 mutant over-expression in Ba/F3 cells, suggesting that excessive ROS1 oncogenic signaling itself induced apoptosis instead of cell growth. Phosphoproteomic analysis and high-throughput inhibitor screening revealed that excessive ROS1 signaling in the TKI-addicted cells phosphorylated or activated apoptosis-related molecules such as FAF1 or p38. Collectively, our findings partly clarify molecular mechanisms of excessive ROS1 oncogenic signaling that mediates paradoxical induction of apoptosis.

Abstract 2938: Tumour-associated macrophage polarisation and re-education with oncolytic viruses

Abstract Tumor-associated macrophages (TAMs) promote key processes in tumour progression through their plasticity and capacity to become polarised by tumours to have an immunosuppressive phenotype. However, the plasticity of these cells provides an opportunity for therapeutic ‘reprogramming’ towards a classically activated inflammatory phenotype thus preventing tumour-associated immunosuppression and inducing anti-tumour immunity. Oncolytic viruses (OV) represent a new class of anti-cancer therapeutics that promote anti-tumour responses through selective tumour cell killing and the induction of systemic anti-tumour immunity. We propose that TAMs can be targeted using an OV, leading to altered macrophage polarization and a reduction in tumour growth and metastasis. Experimental Design: In-vitro, cytotoxicity, viral replication and cytokine expression was assessed in a panel of primary human and murine macrophages following exposure to Sephrevir, an ICP34.5-deleted oncolytic herpes-simplex virus currently in Phase 1/2a trials. In-vivo, murine TS1-PyMT cells were implanted into the mammary fat pads of female FVB mice to establish a syngeneic immunocompetent mouse model of breast cancer. Tumour growth and overall survival were assessed following administration of Sephrevir given either by intratumoural (I.T) or intravenous injection (I.V). Immune cell enumeration and protective immunity were assessed post-mortem by immunofluorescence and flow cytometry. Results: Both primary human and mouse macrophages served as a host for oncolytic viral replication. Sephrevir was also found to attenuate TAM phenotypes as evidenced by increased “M1” receptor signatures (e.g. CD40, CD80, CD86, MHC II), increased pro-inflammatory gene expression (e.g. IL-1, IL-6, IL-8, CXCL10, TNF-a) and increased nitric oxide production. I.T and I.V administration of Sephrevir led to marked tumour shrinkage as well as the recruitment of cytotoxic T cells. Moreover, TAM polarisation was evident based on a change in signature with TAMs becoming skewed to IL-12hi/IL-10lo and a change in the iNOS/arginase1 ratio. Conclusions: Our results demonstrate that Sephrevir is associated with in vivo anti-tumour effects and importantly can be used for manipulating the phenotype of the abundant macrophage population located within the tumour microenvironment. Citation Format: Munitta Muthana, Emer Murphy, Amy Kwan, Natalie Winder, Joe Conner. Tumour-associated macrophage polarisation and re-education with oncolytic viruses [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 2938. doi:10.1158/1538-7445.AM2017-2938

Abstract 2570: Induction of mild oxidative stress as a strategy for reactivation of mutant p53 proteins: KSS72, a small molecule derived from ethacrynic acid restores the biological functions of R248W/Q mutant

Abstract p53 gene mutations in 50% of human cancers drive the emergence of oncogenic genomes and confer resistance to anticancer drugs &amp; apoptosis. Therefore, a pharmacological reactivation of p53 mutant proteins to their wild-type forms has emerged as an intense research area. We have shown that induction of oxidative protein modifications primarily underlie the mechanistic conversion of mutant to wt or wt-like p53 forms (Eur J Medchem 107:233, 2016; Int J Oncol 48:1426, 2016). R248W/Q DNA contact mutations in the p53 core are highly frequent and cause functional inactivation. No small molecules reactivating this p53 mutation are available. Here, we describe the design and synthesis of a small molecule KSS72 using a cell-based screening and its potency in reactivating the R248 p53 mutants. KSS72 is a non-diuretic hydrophobic analog [1-(2,3-dichloro-4-methoxyphenyl)-2-methylenebutan-1-one] of ethacrynic acid (Edecrin) obtained by removing the carboxylate side chain. KSS-72 retained the ability to bind with GSH, inhibit GSTs and induce marked redox-imbalance in tumor cells. KSS72 displayed preferential cytotoxicity (3-4 fold more cell killing) against cancer cells expressing the allele specific R248W mutation (MiaPaca-2) in comparison with the wt p53 or p53-null cancer cell lines. Further, we developed isogenic cell lines expressing the R248W and R248Q mutants in the p53-null H1299 lung cancer cells and evaluated their sensitivity towards KSS72; these models again verified the greater drug efficacy. To prove the hypothesis the higher efficacy of KSS72 stems from the reactivation of mutant p53, the conformation-specific antibodies (Pab1620 for wt and Pab420 for mutant) were employed. Immunoprecipitation and immunostaining using confocal microscopy showed that KSS72 treatment of R248W or R248Q p53-cells results in a marked reciprocal loss of mutant protein and gradual increase of wt-like protein. EMSA revealed a time-dependent restoration of DNA-binding of the mutant p53, which was accompanied by a distinct upregulation of pro-apoptotic signaling pathways mediated by PUMA, Bax, p21cip1 and MDM2 proteins. A strong G2/M arrest and significant apoptosis were observed. Other data showed that KSS72 restores the wt structure and function by covalently binding the p53R248 protein. Pharmacokinetics showed that KSS72 has excellent oral bioavailability with a half-life of 3.5 h. In MiaPaca-2 xenografts developed in nude mice, there was a marked tumor growth suppression with KSS72 as a single drug. In conclusion, KSS72 is an attractive lead compound for further development because p53 reactivation occurred without discernible organ toxicities after oral doses and a wide therapeutic window. The redox-sensitive cysteines involved in the p53 reactivation are being identified by mass spectrometry (supported by CPRIT grants RP130266 &amp; RP170207 to KSS). Citation Format: Surendra R. Punganuru, Hanumantha Rao Madala, Kalkunte S. Srivenugopal. Induction of mild oxidative stress as a strategy for reactivation of mutant p53 proteins: KSS72, a small molecule derived from ethacrynic acid restores the biological functions of R248W/Q mutant [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 2570. doi:10.1158/1538-7445.AM2017-2570

Abstract 2666: Using “omics” to select immunotherapy and conventional therapy combinations

Abstract Background: As only a subset of patients respond to immunotherapies, therapeutic biomarkers are needed to predict which patients will benefit and which should be spared from potentially toxic treatment. Proteins expressed by tumor cells and by the immune microenvironment may predict response to immune checkpoint inhibitors. In non-inflamed tumors, chemotherapy and targeted therapy may stimulate an immune response thereby affecting the relationship between tumor and immune system. Combinations of immunotherapies and conventional therapies are the subject of ongoing clinical trials. We hypothesized that genomic and proteomic evaluation of multiple immune biomarkers in tumor tissue and in lymphocytes would identify a signature that could (a) differentiate between responders and non-responders to checkpoint inhibitors and (b) identify candidates for combination therapy. Methods: A pathologist marked areas of tumor and tumor-associated lymphocytes on archived tissue sections (N=2) of non-small cell lung cancer (NSCLC) and melanoma. The marked areas were microdissected and solubilized to tryptic peptides. In each liquefied tumor sample, 110 protein biomarkers, including 60 immunomarkers were quantified with a mass spectrometry-based proteomic assay. The genomic material was analyzed by whole genome sequencing (WGS) and RNA-seq. Results: Tumor and lymphocytes expressed several immunomarker proteins (eg, PDL1, IDO1, B7H3, B7-2, STAT1, GBP1). The melanoma patient’s tumor and lymphocytes expressed protein markers for response to immunotherapy (PDL1 and IDO1), and the tumor had high mutational burden as identified by WGS. Furthermore, biomarker analysis suggested sensitivity to BRAF inhibitors and resistance to platinum and taxane. The NSCLC patient’s tumor and lymphocytes expressed IDO1 protein, but genomic analysis suggested a non-inflamed tumor. Based on expression levels of ERCC1 and hENT1, one possible regimen for this patient is platinum plus gemcitabine followed by immunotherapy. In one patient, comparison of protein expression in tumor-associated lymphocytes versus distal lymphocytes (&amp;gt;1 mm from marked tumor areas) showed variation &amp;lt; 10% for 11 proteins and &amp;lt; 30% for 14 proteins. Conclusions: Both lymphocytes and tumor expressed immunoproteins that may be used to select patients for approved immunotherapies or clinical trials. Proteomic and genomic profiling also characterized biomarkers that inform selection of targeted therapies and chemotherapies. Ongoing clinical trials of immunotherapy and combination therapies could benefit from precise, quantitative molecular stratification of patients. Protein level cutoffs that correlate with response to immunotherapy are in development. Citation Format: Sarit Schwartz, Robert Heaton, Yuan Tian, Zack Sanborn, Shankar Sellappan, Kerry Scott, Fabiola Cecchi, Steve Benz, Todd Hembrough. Using “omics” to select immunotherapy and conventional therapy combinations [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 2666. doi:10.1158/1538-7445.AM2017-2666

Abstract 2916: The clonal evolution of glioblastoma

Abstract Background: Glioblastoma (GBM) is an aggressive cancer that often recurs despite multimodal therapy. Median survival is 12-15 months. Genomic profiling studies have shown marked tumor heterogeneity with distinct mutations among treated and untreated samples. The Cancer Genome Atlas (TCGA), revealed that mutations in TP53, CDKN2A, PTEN, EGFR and NF1 are predominant in untreated tumors. Of 19 patients who progressed on therapy, seven samples were hypermutated with mutations in mismatch repair proteins, mainly MSH6. We proposed to use the Cellecta Lentiviral-based tagging library, a novel model system to assess the role of intratumor heterogeneity (ITH) in the presumptive tumor-initiating fraction of primary GBM and in the development of resistance to temozolomide (TMZ). From a pool of 30,000,000 barcodes, the system enables the genetic integration of a unique barcode sequence into each cell. Each barcode can be quantitatively tracked via next-generation sequencing, allowing for dynamic monitoring of the subclonal architecture. Methods: GSC 272 and 627 (sensitive and resistant to TMZ) were derived from core biopsies of GBM patients. Cells were transduced with a lentiviral vector containing luciferase. Cells were expanded and infected with the Cellecta Lentiviral library. Multiplicity of infection was determined. Transduced cells were injected into B6.Cg-Foxn1nu/J mice brains using a guide screw system. Half of the mice were treated with TMZ via gavage at two weeks. Brain tumors were removed and total DNA was extracted. Barcode inserts were amplified and the Illumina Sequencing platform was used for barcode quantification. Additionally, whole exome sequencing was performed to assess mutation status. Results: Confirmation of luciferase signal has been performed using a Luciferase Reporter Assay. Multiplicity of infection was found to be 0.15 and 1 for GSC 6-27 and 272 respectively. Initial methylation studies showed GSC 272 to have methylation of MGMT while GSC 627 did not. There was no difference in OS in the TMZ Resistant (GSC 627) untreated vs. treated cohort (with a median OS of 55 days in both groups (N= 23 vs 25 respectively, P= 0.563). TMZ Sensitive (GSC 272) untreated mice did not survive as long as the treated cohort (N= 24 vs. 25, Median OS 43 vs. 206 days, P= 4.61e-09). Barcode and whole exome sequencing results is currently being analyzed. Conclusions: The Cellecta lentiviral tagging system is an innovative way to track ITH and clonal evolution in glioblastoma orthotopic models. We hope to discover novel insights into TMZ treatment response and resistance. Citation Format: Jennifer Brooke Goldstein, Ravesanker Ezhilarasan, Mona Jaffari, Alessandro Carugo, Giulio Draetta, Roeland Verhaak, Sahil Seth, Erik Sulman, Phillip Andrew Futreal. The clonal evolution of glioblastoma [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 2916. doi:10.1158/1538-7445.AM2017-2916

Abstract 1604: NKTR-214 synergizes with radiotherapy to drive tumor regression

Abstract The purpose of this study was to investigate therapeutic and mechanistic synergies between single-dose radiotherapy and systemic administration of NKTR-214. NKTR-214 is a CD122-biased cytokine agonist conjugated with multiple releasable chains of polyethylene glycol. NKTR-214 is designed to provide sustained signaling through the heterodimeric IL-2 receptor pathway (IL-2Rβγ) to preferentially activate and expand effector CD8+ T and NK cells over Regulatory CD4 T cells. Preclinical models demonstrated NKTR-214 preferentially expands effector CD8+ T cells and NK cells within the tumor resulting in marked tumor growth suppression as a single-agent and in combination with checkpoint inhibitors. A phase I/II trial is in progress to evaluate NKTR-214 safety and efficacy in an outpatient setting. Radiation therapy can induce antigen-release and epitope spreading, while NKTR-214 can active and expand antigen-specific effector populations. We hypothesized that the combination of systemic NKTR-214 and local radiotherapy would generate better therapeutic responses than either treatment alone. In this study, we evaluated the combination of systemic NKTR-214 treatment with single fraction high-dose radiotherapy (20 Gy) in multiple murine models. We used flow cytometry, multi-spectral histology, and whole tumor mRNA profiling to investigate local, systemic and potential abscopal immune responses. We used Nur77-GFP reporter mice to enable detection of T cell receptor ligation in vivo and to evaluate the effects of NKTR-214+RT on tumor-reactive T cells. The results from these studies indicate that the combination of NKTR-214 and radiotherapy is synergistic, providing significantly better anti-tumor responses than either monotherapy. Consistent with previous observations, NKTR-214 alone induces expression of a wide range of activation markers expressed by CD4 and CD8 T cells as well as NK cells in the blood, lymph nodes and tumor. The combination of radiotherapy and NKTR-214 was found to have several unique effects including a significant increase (&amp;gt;75%) in the absolute numbers of lymphocytes in the peripheral blood, increased expression of activation markers (CD25, PD-1) by CD8 T cells in the blood and tumor, and increased density of tumor-infiltrating NK cells. Evaluation of tumor infiltrating lymphocytes (TIL) in Nur77-GFP reporter mice revealed that the combination of NKTR-214+RT resulted in a higher frequency of recently activated (Nur77-GFP+) CD8 T cells in treated (irradiated) and abscopal (non-irradiated) tumors. Whole tumor mRNA profiling and multi-spectral histology of these tumors is being assessed to identify key differences in the tumor-microenvironment that may help to define the underlying mechanism of action. Taken together, these data provide evidence of synergy between localized radiotherapy and systemic NKTR-214 treatment via an expansion of activated, tumor-specific CD8 T cells. Citation Format: Michael J. Mcnamara, Melissa Kasiewicz, Ian Hilgart-Martiszus, Ute Hoch, Deborah H. Charych, William L. Redmond. NKTR-214 synergizes with radiotherapy to drive tumor regression [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 1604. doi:10.1158/1538-7445.AM2017-1604

Near infrared-assisted Fenton reaction for tumor-specific and mitochondrial DNA-targeted photochemotherapy.

The strong dependence on oxygen level, low ultraviolet/visible (UV/vis) light penetration depth and the extremely short lifetime of reactive oxygen species (ROS) are the major challenges of photodynamic therapy (PDT) for tumors. Fenton reaction can produce abundant ROS such as reactive hydroxyl radicals (OH) with significantly higher oxidation performance than singlet oxygen (1O2), which, however, has been rarely used in biomedical fields due to strict reaction conditions (favorably in pH range of 3-4, mostly under UV/vis light catalysis). Herein we propose and demonstrate a photochemotherapy (PCT) strategy of cancer therapy using near-infrared (NIR)-assisted tumor-specific Fenton reactions. NIR light-upconverted UV/vis light by upconversion nanoparticles (UCNPs) catalyze the intra-mitochondrial Fenton reaction between the delivered Fe2+ and H2O2 species over-expressed in cancer cell's mitochondria to in-situ kill the cancer cells. The intra-mitochondrial ROS generation of enabled by directly targeting the mitochondrial DNA (mtDNA) helix minimized the distance between the ROS and mtDNA molecules, thus the present PCT strategy showed much enhanced and tumor-specific therapeutic efficacy, as demonstrated by the intratumoral-accelerated OH burst and elevated cytotoxicity. Following the direct intratumoral injection, the PCT revealed marked tumor regression effect invivo. This constructed PCT-agent is the first paradigm of NIR-upconversion catalyzed intra-mitochondrial Fenton reaction in response to tumoral microenvironment, establishing a novel photochemotherapy strategy for efficient cancer therapy.

Renal cell carcinoma histological subtype distribution differs by age, gender, and tumor size in coastal Chinese patients.

The distribution pattern of renal cell carcinoma (RCC) histological subtypes according to age, gender and tumor size has not been well illustrated in RCC patients living in fast-developing regions of China. We recruited 2941 patients with clear cell renal cell carcinoma (ccRCC), papillary renal cell carcinoma (PCC) or chromophobe from two hospitals in coastal China (2004−2012) consecutively and draw 538 American Chinese RCC patients’ data with time matched from the Surveillance, Epidemiology, and End Results database. We found that compared with ccRCC patients, chromophobe patients were more likely to be female (OR: 2.538, 95% CI: 1.923−3.350), younger (OR for 51−60 years old: 0.686; OR for over 60 years old: 0.478; reference: age < 50) and to have a larger maximal diameter (Dmax) (OR for Dmax > 7 cm: 1.883; reference: Dmax ≤ 4 cm). Besides, in comparison with coastal Chinese patients, American Chinese individuals had lower Fuhrman grades (P < 0.001) and had an onset age 10 years delay. In conclusion, we were the first to observe marked gender, age and tumor size differences in the proportional subtype distribution of RCCs in coastal Chinese patients, and also the first to compare coastal Chinese with American Chinese data.

EXCI-CEST: Exploiting pharmaceutical excipients as MRI-CEST contrast agents for tumor imaging

Chemical Exchange Saturation Transfer (CEST) approach is a novel tool within magnetic resonance imaging (MRI) that allows visualization of molecules possessing exchangeable protons with water. Many molecules, employed as excipients for the formulation of finished drug products, are endowed with hydroxyl, amine or amide protons, thus can be exploitable as MRI-CEST contrast agents. Their high safety profiles allow them to be injected at very high doses. Here we investigated the MRI-CEST properties of several excipients (ascorbic acid, sucrose, N-acetyl-d-glucosamine, meglumine and 2-pyrrolidone) and tested them as tumor-detecting agents in two different murine tumor models (breast and melanoma cancers). All the investigated molecules showed remarkable CEST contrast upon i.v. administration in the range 1–3ppm according to the type of mobile proton groups. A marked increase of CEST contrast was observed in tumor regions up to 30min post injection. The combination of marked tumor contrast enhancement and lack of toxicity make these molecules potential candidates for the diagnosis of tumors within the MRI-CEST approach.

Multimodality Imaging of Bone Marrow–Derived Dendritic Cell Migration and Antitumor Immunity

Here, we sought to monitor bone marrow–derived dendritic cell (BMDC) migration and antitumor effects using a multimodal reporter imaging strategy in living mice. BMDCs were transduced with retroviral vector harboring human sodium iodide symporter (hNIS, nuclear imaging reporter), firefly luc2 (optical imaging reporter), and thy1.1 (surrogate marker of NIS and luc2) genes (BMDC/NF cells). No significant differences in biological functions, including cell proliferation, antigen uptake, phenotype expression, and migration ability, were observed between BMDC and BMDC/NF cells. Combined bioluminescence imaging and I-124 positron emission tomography/computed tomography clearly revealed the migration of BMDC/NF cells to draining popliteal lymph nodes at day 7 postinjection. Interestingly, marked tumor protection was observed in mice immunized with TC-1 lysate-pulsed BMDC/NF cells. Our findings suggested that multimodal reporter gene imaging of NIS and luciferase could provide insights into the biological behaviors of dendritic cells in living organisms and could be a useful tool for the optimization of DC-based immunotherapy protocols.

Therapeutic strategies and mechanisms of drug resistance in anaplastic lymphoma kinase (ALK)-rearranged lung cancer.

Anaplastic lymphoma kinase (ALK) gene encoding the receptor tyrosine kinase ALK is expressed as a fusion gene in a variety of carcinomas. The expression of ALK is nearly undetectable in adults, and its activation is normally regulated by its ligands, FAM150A/B. However, ALK gene rearrangements result in constitutive ALK fusion proteins expression via the active promoter of fusion partner genes. ALK fusion proteins dimerize in a ligand-independent manner and lead to the dysregulation of cell proliferation via abnormal constitutive activation of ALK tyrosine kinase. Many ALK tyrosine kinase inhibitors (TKIs) have been developed to date, three of which are currently in clinical use for the treatment of ALK-rearranged non-small cell lung cancer (NSCLC). ALK TKIs often achieve marked tumor regression in NSCLC patients with ALK rearrangements; however, ALK TKI-resistant tumors inevitably emerge within a few years in most cases. In this review, we summarize diverse ALK TKI resistance mechanisms identified in NSCLC with ALK rearrangements, and review potential therapeutic strategies to overcome ALK TKI resistance in these patients.

PLK1 inhibition enhances temozolomide efficacy in IDH1 mutant gliomas.

Despite multimodal therapy with radiation and the DNA alkylating agent temozolomide (TMZ), malignant gliomas remain incurable. Up to 90% of grades II-III gliomas contain a single mutant isocitrate dehydrogenase 1 (IDH1) allele. IDH1 mutant-mediated transformation is associated with TMZ resistance; however, there is no clinically available means of sensitizing IDH1 mutant tumors to TMZ. In this study we sought to identify a targetable mechanism of TMZ resistance in IDH1 mutant tumors to enhance TMZ efficacy. IDH1 mutant astrocytes rapidly bypassed the G2 checkpoint with unrepaired DNA damage following TMZ treatment. Checkpoint adaptation was accompanied by PLK1 activation and IDH1 mutant astrocytes were more sensitive to treatment with BI2536 and TMZ in combination (<20% clonogenic survival) than either TMZ (~60%) or BI2536 (~75%) as single agents. In vivo, TMZ or BI2536 alone had little effect on tumor size. Combination treatment caused marked tumor shrinkage in all mice and complete tumor regression in 5 of 8 mice. Mutant IDH1 promotes checkpoint adaptation which can be exploited therapeutically with the combination of TMZ and a PLK1 inhibitor, indicating PLK1 inhibitors may be clinically valuable in the treatment of IDH1 mutant gliomas.

Evaluation and response of mucin pools in primary rectal cancer tissue during chemoradiotherapy (CRT).

798 Background: Mucinous carcinoma (MC) has been defined as carcinoma with &gt; 50% of tumor volume showing mucin pool (MP). The incidence of MC had been reported to be 4 to 12% of colorectal cancer and to be less effective for chemotherapy and CRT. The incidence of MC was 3 to 8% in rectal cancer treated with surgery alone and 13 to 24% in patients treated with CRT. These findings suggest that MP may be induced by CRT in some patients. We therefore compared the degree of MP in MRI findings before CRT, after CRT and in resected specimens. Methods: The study group comprised 205 patients with rectal cancer who received CRT (40 to 45 Gy) from 2006 through 2014. MPs on MRI were evaluated using T2-weighted fast-spin echo images, and the MP area ratios on maximum cross-section of the primary tumor were calculated. An MP area ratio of 0% was designated as class 0, 1 to 9% as class I, 10 to 29% as class II, 30 to 50% as class III, and 50% or higher as class IV. Results: On MRI before CRT, the MP area ratio was class 0 in 181 patients (88%), class I in 11 (5%), and class II or higher in 13 (6%). On MRI after CRT, the MP area ratio was class 0 in 186 patients (91%), class I in 4 (2%), and class II or higher in 15 (7%). The prevalence of MP classes did not change appreciably. The MP class evaluated on MRI before and after CRT changed by 2 or more levels in only 2 patients, both of whom had marked tumor shrinkage. Among 175 patients with an MP area ratio of class 0 or I in the resected specimens, the MRI findings after CRT were consistent with the findings of the resected specimens. However, the MP area ratio was underestimated by 2 or more levels on MRI in 14 (47%) of 30 patients who had an MP area ratio of class II or higher. A pathological complete response (pCR) was obtained in 24 patients (12%), all of whom had an MP area ratio of class 0 or I on MRI before CRT. No patient with an MP area ratio of class II or higher before CRT had a pCR. Conclusions: The degree of MP evaluated on MRI did not change during CRT. In patients who had an MP area ratio of &gt; 10% in their resected specimens, the evaluation of MP on MRI was often underestimated. Patients with an MP area ratio of &gt; 10% before CRT had a poor response to CRT, with no pCR.

Dendritic Cell Vaccination Combined with Lenalidomide and Programmed Death-1 (PD-1) Blockade has Synergistically Induced a Marked Tumor Regression in a Murine Myeloma Model

Dendritic Cell Vaccination Combined with Lenalidomide and Programmed Death-1 (PD-1) Blockade has Synergistically Induced a Marked Tumor Regression in a Murine Myeloma Model

In Vitro and In Vivo Activity of Lucitanib in FGFR1/2 Amplified or Mutated Cancer Models

The fibroblast growth factor receptor (FGFR) pathway has been implicated both as an escape mechanism from anti-angiogenic therapy and as a driver oncogene in different tumor types. Lucitanib is a small molecule inhibitor of vascular endothelial growth factor (VEGF) receptors 1 to 3 (VEGFR1 to 3), platelet derived growth factor α/β (PDGFRα/β) and FGFR1–3 tyrosine kinases and has demonstrated activity in a phase I/II clinical study, with objective RECIST responses in breast cancer patients with FGFR1 or FGF3/4/19 gene amplification, as well as in patients anticipated to benefit from anti-angiogenic agents. We report here the in vitro and in vivo antitumor activity of lucitanib in experimental models with or without FGFR1/2 amplification or mutations. In cell assays, lucitanib potently inhibited the growth of tumor cell lines with amplified FGFR1 or mutated/amplified FGFR2. In all xenograft models studied, lucitanib demonstrated marked tumor growth inhibition due to potent inhibition of angiogenesis. Notably, in two lung cancer models with FGFR1 amplification, the antitumor efficacy was higher, suggesting that the simultaneous inhibition of VEGF and FGF receptors in FGFR1 dependent tumors can be therapeutically advantageous. Similar antitumor activity was observed in FGFR2 wild-type and amplified or mutated xenograft models. Pharmacokinetic studies showed lucitanib plasma concentrations in the micro/sub-micromolar range demonstrated drug accumulation following repeated lucitanib administration.

A case report of curative distal gastrectomy for stage IV gastric cancer after chemoradiotherapy in a patient with a gastrojejunal gastric bypass.

BackgroundAdvanced gastric cancer in the lower third of the stomach often results in stricture of the gastric cavity and digestive symptoms. Gastrojejunostomy has been suggested to improve such symptoms, and the advent of new anticancer agents for gastric cancer has improved the response rate of the disease, which makes it possible to perform R0 gastrectomy in part of patients with stage IV gastric cancer. We experienced a rare case in which a patient with stage IV gastric cancer and cancerous pyloric stenosis was treated with R0 surgery after undergoing a gastrojejunal bypass procedure and multidisciplinary treatment. There have not been any previous reports about cases in which a previous gastrojejunostomy was utilized as a reconstruction route during distal gastrectomy in a patient with gastric cancer that had been treated with chemotherapy and/or CRT.Case presentationAn 80-year-old female with advanced gastric cancer and pyloric stenosis was admitted to Kagoshima University Hospital. As peritoneal washing cytology produced a positive result, laparoscopic gastrojejunostomy (modified Devine procedure) was performed to improve food passage, and S-1 (100 mg/body, days 1–14) plus paclitaxel (120 mg/body, days 1 and 15) was administered. Although the tumor was temporarily reduced in size, an abdominal computed tomography scan obtained after four courses of chemotherapy showed progressive disease. Thus, chemoradiotherapy (56 Gy, S-1: 60 mg/body, CDDP: 5 mg/body, days 1–5) was indicated. Marked tumor shrinkage and negative peritoneal washing cytological results were achieved. Curative gastrectomy with D2 lymphadenectomy was performed. We carried out distal gastrectomy and lymph node dissection, and the gastrojejunostomy produced as a gastric bypass in the previous operation was preserved. The patient has not suffered a tumor relapse in 4 years since the surgery.ConclusionsWe surgeons increase a chance to perform R0 gastrectomy for stage IV gastric cancer following intensive chemotherapy and/or CRT. We should choose proper position of gastrojejunostomy in producing alimentary bypass for stage IV gastric cancer patients to facilitate curative surgery.

Enhanced anti-tumour activity of the combination of the novel MEK inhibitor WX-554 and the novel PI3K inhibitor WX-037

PurposeTumours frequently have defects in multiple oncogenic pathways, e.g. MAPK and PI3K signalling pathways, and combinations of targeted therapies may be required for optimal activity. This study evaluated the novel MEK inhibitor WX-554 and the novel PI3K inhibitor WX-037, as single agents and in combination, in colorectal carcinoma cell lines and tumour xenograft-bearing mice.MethodsIn vitro growth inhibition, survival and signal transduction were measured using the Sulforhodamine B, clonogenic and Western blotting assays, respectively, in HCT116 and HT29 cell lines. In vivo anti-tumour efficacy and pharmacokinetic properties were assessed in HCT116 and HT29 human colorectal cancer xenograft tumour-bearing mice.ResultsThe combination of WX-554 and WX-037 exhibited marked synergistic growth inhibition in vitro, which was associated with increased cytotoxicity and enhanced inhibition of ERK and S6 phosphorylation, compared to either agent alone. Pharmacokinetic analyses indicated that there was no PK interaction between the two drugs at low doses, but that at higher doses, WX-037 may delay the tumour uptake of WX-554. In vivo efficacy studies revealed that the combination of WX-037 and WX-554 was non-toxic and exhibited marked tumour growth inhibition greater than observed with either agent alone.ConclusionThese studies show for the first time that combination treatment with the novel MEK inhibitor WX-554 and the novel PI3K inhibitor WX-037 can induce synergistic growth inhibition in vitro, which translates into enhanced anti-tumour efficacy in vivo.Electronic supplementary materialThe online version of this article (doi:10.1007/s00280-016-3186-4) contains supplementary material, which is available to authorized users.

MiR-9 and miR-200 Regulate PDGFRβ-Mediated Endothelial Differentiation of Tumor Cells in Triple-Negative Breast Cancer.

Organization of cancer cells into endothelial-like cell-lined structures to support neovascularization and to fuel solid tumors is a hallmark of progression and poor outcome. In triple-negative breast cancer (TNBC), PDGFRβ has been identified as a key player of this process and is considered a promising target for breast cancer therapy. Thus, we aimed at investigating the role of miRNAs as a therapeutic approach to inhibit PDGFRβ-mediated vasculogenic properties of TNBC, focusing on miR-9 and miR-200. In MDA-MB-231 and MDA-MB-157 TNBC cell lines, miR-9 and miR-200 promoted and inhibited, respectively, the formation of vascular-like structures in vitro Induction of endogenous miR-9 expression, upon ligand-dependent stimulation of PDGFRβ signaling, promoted significant vascular sprouting of TNBC cells, in part, by direct repression of STARD13. Conversely, ectopic expression of miR-200 inhibited this sprouting by indirectly reducing the protein levels of PDGFRβ through the direct suppression of ZEB1. Notably, in vivo miR-9 inhibition or miR-200c restoration, through either the generation of MDA-MB-231-stable clones or peritumoral delivery in MDA-MB-231 xenografted mice, strongly decreased the number of vascular lacunae. Finally, IHC and immunofluorescence analyses in TNBC specimens indicated that PDGFRβ expression marked tumor cells engaged in vascular lacunae. In conclusion, our results demonstrate that miR-9 and miR-200 play opposite roles in the regulation of the vasculogenic ability of TNBC, acting as facilitator and suppressor of PDGFRβ, respectively. Moreover, our data support the possibility to therapeutically exploit miR-9 and miR-200 to inhibit the process of vascular lacunae formation in TNBC. Cancer Res; 76(18); 5562-72. ©2016 AACR.

Echocardiographic study of cardiac rhabdomyomas from fetuses to children: about a tunisian hospital experience

Aim was to report our experience with regard to patients with cardiac rhabdmyomas , focusing on echocardigraphic finding ,cardiac outcome and management Methods Patients with cardiac rhabdomyomas diagnosis were retrospectively analyzed. during the period betwen 2000 and 2017 . Results A total of 17 rhabdomyomas were diagnosed .seven patients were detected prenatally, six patients in the neonatal period and four patient in early infancy. , Tumors were mostly localized in the left ventricle (15/17) , their size ranged from 13*10mm to 55*40mm and it was obstructive in 7 cases. . The tumors were singular in 8 patients and multiple in 9 . We diagnosed tuberous sclerosis (TSC) in 9 babies. we reported 4 deaths , three patients required surgery because of hemodynamic obstruction in two cases and resistant arrythmias in one baby . after a follow up of 45 months , . 5 patients had marked tumor regression and 9 had complete tumor regression ConCLUSION Cardiac rhabdomyoma may have different presentations and clinical course.it thought to be a benign tumor which tend to a spontaneous regression Surgery is only necessary when hemodynamically significant obstruction is present or resistant arrythmia . As these tumors are associated with long-term development of TSC a follow-up was mandatory .