Tumor Growth In Animal Models Research Articles

Consumption of whole grain/bran rye instead of refined wheat decrease concentrations of TNF-R2, e-selectin, and endostatin in an exploratory study in men with prostate cancer

Rye consumption has shown beneficial effects on prostate cancer tumors, as indicated by slower initial tumor growth in animal models and lowering of prostate-specific antigen (PSA) in humans. This study evaluated the effects of whole grain/bran rye consumption on low-grade inflammation and endothelial function biomarkers in men with prostate cancer. Seventeen men with untreated, low-grade prostate cancer consumed 485g rye whole grain and bran products (RP) per day or refined wheat products with added cellulose (WP) in a randomized crossover design. Fasting blood samples were taken before and after 2, 4, and 6 weeks of treatment. Concentrations of tumor nuclear factor-receptor 2 (TNF-R2), e-selectin, and endostatin were significantly lower after consumption of the RP diet compared with WP (p<0.05). Cathepsin S concentration was positively correlated to TNF-R2 and endostatin concentrations across all occasions. Strong correlations were consistently found between intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and between interleukin-6 (IL-6) and interleukin-1 receptor antagonist (IL-1RA). No effect of intervention was found in 92 inflammation-related protein biomarkers measured in a proximity extension assay. RP diet lowered TNF-R2, e-selectin, and endostatin, compared with WP in men with prostate cancer. These effects were accompanied by a reduction in PSA.

Columbamine suppresses hepatocellular carcinoma cells through down-regulation of PI3K/AKT, p38 and ERK1/2 MAPK signaling pathways

Hepatocellular carcinoma (HCC) as primary liver cancer in adults is the most common cause led to internal cirrhosis responsible for patients' death, which resulted in nearly a million deaths worldwide on both males and females in the developing and developed countries. Unfortunately, up to date, there are no highly effective treatment of medicine on HCC as lack of comprehensive cellular and molecular mechanism. According to the sources of human ancient history of medicine, traditional medicine could provide unique treatment to discontinue the challenging HCC. In this study, we inspected the effect of Columbamine (Col; C20H21NO5), an alkaloid isolated from calumba, on HCC utilizing three HCC cell-lines i.e. SMMC7721, HepG2 and Hep3B. Our data collected from these cell-lines exhibit strong Col suppression on the cell growth accompanying the dosage-dependent suppression, and we further confirmed the suppression on the tumor-growth in animal model. Rational of the Col suppression presents cellular mechanism by limiting the proliferation and colony formation of the cells marked with decreased expression of PCNA. Meanwhile decreases of migration indicated with increasing expression of E-cadherin and decreasing expression of N-cadherin, and of invasion labelled with decreasing expressions of MMP2 and MMP9, are accompanying the Col suppression along with the Col promoted apoptosis of the tumor cells. This programmed cell death marketed with cleaved Caspase 3 plus PAPR proteins, up-regulation of BAD and down-regulation of BCL2 is linked the Col suppression to unique calcium-related pathways. Our results unveiled that the Columbamine suppression on HCC based on the traditional medicine are clearly associated with PI3K/AKT, p38 and ERK1/2 MAPKs signaling pathways and guide further research orientation for developing the Col medicine against hepatocellular carcinoma.

Integrin CD11b activation drives anti-tumor innate immunity

Myeloid cells are recruited to damaged tissues where they can resolve infections and tumor growth or stimulate wound healing and tumor progression. Recruitment of these cells is regulated by integrins, a family of adhesion receptors that includes integrin CD11b. Here we report that, unexpectedly, integrin CD11b does not regulate myeloid cell recruitment to tumors but instead controls myeloid cell polarization and tumor growth. CD11b activation promotes pro-inflammatory macrophage polarization by stimulating expression of microRNA Let7a. In contrast, inhibition of CD11b prevents Let7a expression and induces cMyc expression, leading to immune suppressive macrophage polarization, vascular maturation, and accelerated tumor growth. Pharmacological activation of CD11b with a small molecule agonist, Leukadherin 1 (LA1), promotes pro-inflammatory macrophage polarization and suppresses tumor growth in animal models of murine and human cancer. These studies identify CD11b as negative regulator of immune suppression and a target for cancer immune therapy.

P-332 - Intravenous antioxidants, laetrile and artesunate as integrative treatment in oncology

Since 1970, Linus Pauling established that the C-Vitamin could potentially and selectively kill tumors by the induction of the hydrogen peroxide in the malignant cells, but not in the healthy cells. Increased levels of reactive oxygen species (ROS) including H2O2 are thought to play an important role in the initiation and progression of cancer. Previous reports showed that vitamin C treatment induced cytotoxicity by adenosine triphosphate (ATP) depletion in some cancer cells. High-dose vitamin C suppressed tumor growth in animal models and tissue culture and, therefore, may indeed have applications as a novel treatment for various cancers. ALA, a member of the B vitamin family is a coenzyme in the multienzyme complexes of dehydrogenase and aminocaproic acid decarboxylase and can inhibit cancer cell proliferation in cervical cancer and colon cancer. Hydrogen cyanide is thought to be the main anticancer compound formed from laetrile via in situ release. Artemisinins have demonstrated cytotoxic effects against a variety of cancer cells by inducing cell cycle arrest, promoting apoptosis, preventing angiogenesis, and abrogating cancer invasion and metastasis. The aim is to show the integrative intravenous oncology protocols and the possible anticancer mechanisms behind.

Therapeutic efficacy of a synthetic epsin mimetic peptide in glioma tumor model: uncovering multiple mechanisms beyond the VEGF-associated tumor angiogenesis.

Binding of epsin ubiquitin-interacting motif (UIM) with ubiquitylated VEGFR2 is a critical mechanism for epsin-dependent VEGFR2 endocytosis and physiological angiogenesis. Deletion of epsins in vessel endothelium produces uncontrolled tumor angiogenesis and retards tumor growth in animal models. The aim of this study is to test the therapeutic efficacy and targeting specificity of a chemically-synthesized peptide, UPI, which compete for epsin binding sites in VEGFR2 and potentially inhibits Epsin-VEGFR2 interaction in vivo, in an attempt to reproduce an epsin-deficient phenotype in tumor angiogenesis. Our data show that UPI treatment significantly inhibits and shrinks tumor growth in GL261 glioma tumor model. UPI peptide specifically targets VEGFR2 signaling pathway revealed by genetic and biochemical approaches. Furthermore, we demonstrated that UPI peptide treatment caused serious thrombosis in tumor vessels and damages tumor cells after a long-term UPI peptide administration. Besides, we revealed that UPI peptides were unexpectedly targeted cancer cells and induced apoptosis. We conclude that UPI peptide is a potent inhibitor to glioma tumor growth through specific targeting of VEGFR2 signaling in the tumor vasculature and cancer cells, which may offer a potentially novel treatment for cancer patients who are resistant to current anti-VEGF therapies.

Biomarker identification for statin sensitivity of cancer cell lines

Statins are potent cholesterol reducing drugs that have been shown to reduce tumor cell proliferation in vitro and tumor growth in animal models. Moreover, retrospective human cohort studies demonstrated decreased cancer-specific mortality in patients taking statins. We previously implicated membrane E-cadherin expression as both a marker and mechanism for resistance to atorvastatin-mediated growth suppression of cancer cells; however, a transcriptome-profile-based biomarker signature for statin sensitivity has not yet been reported. Here, we utilized transcriptome data from fourteen NCI-60 cancer cell lines and their statin dose-response data to produce gene expression signatures that identify statin sensitive and resistant cell lines. We experimentally confirmed the validity of the identified biomarker signature in an independent set of cell lines and extended this signature to generate a proposed statin-sensitive subset of tumors listed in the TCGA database. Finally, we predicted drugs that would synergize with statins and found several predicted combination therapies to be experimentally confirmed. The combined bioinformatics-experimental approach described here can be used to generate an initial biomarker signature for anticancer drug therapy.

In a randomized trial in prostate cancer patients, dietary protein restriction modifies markers of leptin and insulin signaling in plasma extracellular vesicles.

SummaryObesity, metabolic syndrome, and hyperleptinemia are associated with aging and age‐associated diseases including prostate cancer. One experimental approach to inhibit tumor growth is to reduce dietary protein intake and hence levels of circulating amino acids. Dietary protein restriction (PR) increases insulin sensitivity and suppresses prostate cancer cell tumor growth in animal models, providing a rationale for clinical trials. We sought to demonstrate that biomarkers derived from plasma extracellular vesicles (EVs) reflect systemic leptin and insulin signaling and respond to dietary interventions. We studied plasma samples from men with prostate cancer awaiting prostatectomy who participated in a randomized trial of one month of PR or control diet. We found increased levels of leptin receptor in the PR group in total plasma EVs and in a subpopulation of plasma EVs expressing the neuronal marker L1CAM. Protein restriction also shifted the phosphorylation status of the insulin receptor signal transducer protein IRS1 in L1CAM+ EVs in a manner suggestive of improved insulin sensitivity. Dietary PR modifies indicators of leptin and insulin signaling in circulating EVs. These findings are consistent with improved insulin and leptin sensitivity in response to PR and open a new window for following physiologic responses to dietary interventions in humans.

Combination cisplatin and sulforaphane treatment reduces proliferation, invasion, and tumor formation in epidermal squamous cell carcinoma.

Epidermal squamous cell carcinoma is an extremely common type of cancer. Early tumors can be successfully treated by surgery, but recurrent disease is aggressive and resistant to therapy. Cisplatin is often used as a treatment, but the outcome is rarely satisfactory. For this reason new strategies are required. Sulforaphane is a diet-derived cancer prevention agent that is effective in suppressing tumor growth in animal models of skin cancer. We monitored the efficacy of sulforaphane and cisplatin as a combined therapy for squamous cell carcinoma. Both agents suppress cell proliferation, growth of cancer stem cell spheroids, matrigel invasion and migration of SCC-13 and HaCaT cells, and combination treatment is more efficient. In addition, SCC-13 cell derived cancer stem cells are more responsive to these agents than non-stem cancer cells. Both agents suppress tumor formation, but enhanced suppression is observed with combined treatment. Moreover, both agents reduce the number of tumor-resident cancer stem cells. SFN treatment of cultured cells or tumors increases apoptosis and p21Cip1 level, and both agents increase tumor apoptosis. We suggest that combined therapy with sulforaphane and cisplatin is efficient in suppressing tumor formation and may be a treatment option for advanced epidermal squamous cell carcinoma.

Blocking IL-10 signalling at the time of immunization does not increase unwanted side effects in mice

BackgroundCancer therapeutic vaccine induced cytotoxic T cell (CTL) responses are pivotal for the killing of tumour cells. Blocking interleukin 10 (IL-10) signalling at the time of immunization increases vaccine induced CTL responses and improves prevention of tumour growth in animal models compared to immunization without an IL-10 signalling blockade. Therefore, this immunization strategy may have potential to curtail cancer in a clinical setting. However, IL-10 deficiency leads to autoimmune disease in the gut. Blocking IL-10 at the time of immunization may result in unwanted side effects, especially immune-pathological diseases in the intestine.MethodsWe investigated whether blocking IL-10 at the time of immunization results in intestinal inflammation responses in a mouse TC-1 tumour model and in a NOD autoimmune disease prone mouse model.ResultsWe now show that blocking IL-10 at the time of immunization increases IL-10 production by CD4+ T cells in the spleen and draining lymph nodes, and does not result in blood cell infiltration to the intestines leading to intestinal pathological changes. Moreover, immunization with papillomavirus like particles combined with simultaneously blocking IL-10 signalling does not increase the incidence of autoimmune disease in Non-obese diabetic (NOD) mice.ConclusionsOur results indicate that immunization with an IL-10 inhibitor may facilitate the generation of safe, effective therapeutic vaccines against chronic viral infection and cancer.

A Purified Serine Protease from Nereis virens and Its Impaction of Apoptosis on Human Lung Cancer Cells

Nereis active protease (NAP) is a novel fibrinolytic active serine protease from the polychaete Nereis virens. In this study, NAP was purified from Nereis virens and the effects of NAP on human lung cancer cells were investigated. Our results indicated that NAP inhibited the proliferation and induced apoptosis of H1299 cells in a time- and dose-dependent manner. The loss of mitochondrial membrane potential, the activation of Bax and cleaved-caspase 3/9, the release of cytochrome C, and the suppression of Bcl-2 and poly-ADP ribose polymerase were observed in NAP-treated H1299 cells by flow cytometry and Western blotting. Moreover, the expression levels of Bax and Bcl-2 mRNA were determined by real-time quantitative polymerase chain reaction and the Bax/Bcl-2 expression ratio was increased in the NAP-treated cell lines. The results indicated that NAP-induced apoptosis may be related to mitochondria mediated apoptosis and occurs through caspase-dependent pathways. Then, the effects of NAP on tumor growth in animal models were observed, where 5 or 10 mg/kg of NAP noticeably reduced tumor volume and weight and increased apoptosis as determined by Western blotting when compared to the negative control group. Therefore, our findings suggest that NAP could be a hopeful anticancer medicine for its propensity to inhibit growth and induce of apoptosis in human lung cancer cells.

Abstract 5641: Effects of G1T48, a novel orally bioavailable selective estrogen receptor degrader (SERD), and the CDK4/6 inhibitor, G1T38, on tumor growth in animal models of endocrine resistant breast cancer

Abstract Background: The combination of targeting the CDK4/6 and ER signaling pathways with palbociclib and fulvestrant is a proven therapeutic strategy for the treatment of ER positive breast cancer. However, the poor physicochemical properties of fulvestrant require monthly intramuscular injections to patients, which limit the pharmacokinetic and pharmacodynamic activity of the compound. Therefore, an orally available compound that more rapidly reaches steady state may lead to a better clinical response in patients. Here we report the preclinical characterization of G1T48, a novel, orally bioavailable, non-steroidal small molecule inhibitor of ERα, which is a potent, selective antagonist that down regulates ERα in vitro and in vivo in ER-positive models of breast cancer. Methods: Breast cancer cells expressing clinically relevant ESR1 mutations (ER-Y537S, ER-D538G) were threated with G1T38, G1T48, and mechanistically distinct SERMs/SERDs and cellular proliferation was assessed by measuring DNA content (Hoechst dye). Ovariectomized nu/nu mice bearing xenograft tumors of clinically relevant tamoxifen (TamR) and aromatase (long term estrogen deprived) resistant ER+ breast cancer were treated with G1T38 and G1T48, alone or in combination, with clinically relevant comparators. Time to progression and tumor volume were assessed over a 4 week dosing period. Results: G1T38 and G1T48 significantly inhibited cellular proliferation of MCF7 breast cancer cells bearing endocrine resistant ER mutations, ER-Y537S and ER-D538G. G1T48 treatment led to dramatic reductions in ER protein levels. Importantly, tumor growth inhibition was observed in mouse models of sensitive and resistant human breast cancer when G1T48 was dosed as a single agent or in combination with G1T38, a potent, selective CDK4/6 inhibitor. Conclusions: G1T38, a novel CDK4/6 inhibitor, and G1T48, a novel SERD, either alone or in combination, demonstrated highly potent inhibition of tumor growth in animal models of tamoxifen and aromatase resistance. G1T48 also demonstrated activity in models of endocrine resistance mediated by ER mutation. G1T48 is currently completing IND enabling studies. Citation Format: Suzanne E. Wardell, Alexander P. Yllanes, Jennifer G. Baker, Robert M. Baldi, Taylor K. Krebs, Jessica Sorrentino, John Bisi, Jay Strum, John D. Norris. Effects of G1T48, a novel orally bioavailable selective estrogen receptor degrader (SERD), and the CDK4/6 inhibitor, G1T38, on tumor growth in animal models of endocrine resistant breast cancer [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 5641. doi:10.1158/1538-7445.AM2017-5641

Targeting Smoothened Sensitizes Gastric Cancer to Chemotherapy in Experimental Models

BackgroundThe Hedgehog pathway receptor smoothened (SMO) has critical roles in tumor progression. However, whether SMO is a key factor regulating gastric cancer chemotherapy resistance is unknown.Material/MethodsWe investigated the potential functions of SMO in inducing gastric cancer paclitaxel resistance in clinical samples, gastric cancer cell lines (424GC and AGS), and subcutaneous syngeneic mouse models.ResultsWe found high SMO expression in paclitaxel-resistant gastric cancer clinical samples. Paclitaxel gastric cancer cells had higher SMO expression than in drug-sensitive cells. Upregulating SMO expression induced paclitaxel resistance in gastric cells lines via enhancing cell proliferation and inhibiting apoptosis. The combination of IPI-926, an inhibitor of SMO, with paclitaxel decreased cell viability of paclitaxel-resistant gastric cancer cells in vitro and controlled tumor growth in animal models.ConclusionsThe Hedgehog pathway receptor SMO is an important regulator of gastric cancer paclitaxel resistance and could be a target for sensitizing paclitaxel-resistant tumors.

Reduced Klotho expression contributes to poor survival rates in human patients with ovarian cancer, and overexpression of Klotho inhibits the progression of ovarian cancer partly via the inhibition of systemic inflammation in nude mice.

Klotho is a recently discovered anti‑aging gene, which has been reported as a tumor suppressor in numerous human malignancies; however, the role of Klotho in human ovarian cancer remains to be elucidated. The aim of the present study was to detect the expression of Klotho and evaluate its association with the progression of human ovarian cancer. A clinical follow‑up study of 120patients with ovarian cancer and 78normal controls was conducted. The expression levels of Klotho were determined by western blotting and immunohistochemistry. The results demonstrated that high Klotho expression levels were detected in all normal controls, whereas the positive rate of Klotho was 61.6% in the ovarian cancer group, which was significantly decreased compared with in the control group (P<0.01). Furthermore, reduced Klotho expression was significantly correlated with decreased survival rates in patients with ovarian cancer (P=0.025). Subsequently, Klotho levels were detected in seven human ovarian cancer cell lines by western blotting. The results demonstrated that the highest levels of Klotho were detected in CaOV3 cells, medium levels of Klotho were detected in CaOV4 and SKOV‑3 cells, and almost no Klotho was detected in the other four cell lines: OVCA432, OVCAR‑5, OVCAR‑8 and A2780 cells. The association between Klotho levels and cell proliferation was determined by MTT assay, and the results indicated that higher levels of Klotho inhibited the proliferation of A2780 and OVCAR‑5 cells, whereas reduced Klotho expression promoted cell growth of CaOV3 and SKOV‑3 cells. In addition, the plasma levels of inflammatory cytokines in tumor‑bearing mice and normal control mice were detected by enzyme‑linked immunosorbent assay, and plasma interleukin (IL)‑6 and IL‑1β levels were elevated in all tumor‑bearing mice. Notably, the mRNA expression levels of IL‑6 were significantly higher in the liver, ovaries and kidneys of Klotho‑/‑ mice compared with in wild type mice (P<0.01), thus indicating that aberrant Klotho expression may contribute to systemic inflammation in Klotho‑/‑ mice. Finally, the invivo antitumor role of aberrant Klotho expression was determined in a nude mice model. A2780 cells were transfected with pCMV6‑Klotho and the stably transfected cells were screened; the mice were injected with the stably transfected cells. The results indicated that tumor volume and tumor weight were significantly decreased in the pCMV6‑Klotho group compared with in the pCMV6 vector group (P<0.01). These findings suggest that overexpression of Klotho may suppress tumor growth in animal models. In conclusion, Klotho was demonstrated to act as a potent tumor suppressor in human ovarian cancer cells. Reduced Klotho expression was detected in the specimens of patients with ovarian cancer, and overexpression of Klotho significantly inhibited cell proliferation of human ovarian cancer cells. Therefore, Klotho may be considered a useful key target for the molecular therapy of human ovarian cancer.

Phase I study of defactinib combined with pembrolizumab and gemcitabine in advanced cancer.

TPS505 Background: Focal adhesion kinase (FAK) is consistently hyperactivated in pancreatic ductal adenocarcinoma (PDAC), and FAK signaling is a key driver in forming its fibrotic and proinflammatory tumor microenvironment. Inhibition of FAK signaling leads to significant reduction of pancreatic tumor growth in animal models. Indeed, tumors treated with FAK inhibitors displayed markedly reduced tumor fibrosis and decreased immunosuppressive myeloid cells. Furthermore, our preclinical work has demonstrated that FAK- and PD-1 inhibitors elicit significant tumor regression, and the maximal response was achieved by combining FAK- and PD-1 inhibitors with gemcitabine, suggesting the need for a cytotoxic agent to bolster antigen presentation (Jiang H et al, Nature Medicine 2016). Defactinib is an orally available, potent ATP-competitive, FAK inhibitor with a recommended phase II dose (RP2D) of 400 mg twice daily. Methods: Eligible patients will be treated according to the dose escalation schema. A 3+3 design is used until the first occurrence of dose-limiting toxicity, and then switches to a continuous assessment design. The study has an expansion portion (group A and B) at the RP2D. Group A includes metastatic PDAC patients who are stable at least 4 months on front-line nab-paclitaxel/gemcitabine, and group B includes metastatic PDAC patients progressed on ≥ 1 chemotherapy line. Key eligibility criteria include patients with advanced solid tumors (dose escalation portion) or advanced PDAC (expansion cohort); age ≥18 years; ECOG score ≤1; normal organ function; and no history autoimmunity. The primary endpoint is to determine the RP2D. Secondary endpoints include objective response rate, progression-free survival and overall survival. The exploratory endpoints include developing a molecular and immune signature for treatment response. This trial is actively enrolling and funded by Precision Medicine Research Associate and Barnes Jewish Foundation. Clinical trial information: NCT02546531. [Table: see text]

Phase II Study of the Combination of Interleukin-2 with Zoledronic Acid As Maintenance Therapy Following Autologous Stem Cell Transplant in Patients with Multiple Myeloma

Background:Multiple myeloma is still today an incurable disease. The many therapeutic techniques and new therapies proposed in recent years have extended survival but did not allow for healing. Further study allowed to demonstrate that a maintenance could be useful to control the progression of disease. However, there is no clear indication for which maintenance has to be used after a first line of induction therapy. The technique of allograft, used in patients at highest risk, demonstrates that the immune response to the residual disease plays a key role in the success of this technique. Among the major players in response to myeloma, in allogeneic stem cell transplantation, gamma delta lymphocytes play a significant action: complete response after allogeneic few months later (also the molecular level) happen in parallel with the presence in the bone marrow of a significant proportion of lymphocytes with gamma delta oligoclonal expression of TCR rearrangements.Zoledronic acid induces proliferation of these cells by the production of several cytokines, in particular interleukin-2 (IL-2). Furthermore, T lymphocytes Vdelta2 are proved to be crucial antineoplastic mediators and, after expansion in vitro, capable of controlling tumor growth in animal models. These data confirm the hypothesis that gammadelta lymphocytes have a role in controlling the growth of myeloma plasma cells and can be active on the residual disease after autologous stem cell transplant. We planned to evaluate the role of the association of Zoledronate and IL-2 in vivo as post ASCT maintenance therapy in patients with newly diagnosed multiple myeloma (NDMM).Methods:This is a single arm phase II multicenter ongoing study of the combination of IL-2 with zoledronic acid as maintenance therapy for NDMM patients post ASCT. The primary objective was to establish safety and efficacy of IL-2 as maintenance therapy. The secondary objective was to evaluate the immunological expansion of gamma delta lymphocytes. Eligible patients had undergone ASCT, with melphalan as a preparative regimen. At July 2016, forty two patients in very good partial remission (VGPR) have been enrolled in the study (total planned enrollment: 43 pts) and started maintenance therapy 90-180 days post ASCT.Maintenance schedule included IL2 and zoledronic acid. IL2 was administered at a fixed dose of 2 x 106UI from day 1 to day 7 for the first cycle and with the maximum tolerated dose (up to a max of 8 x 106UI) from day 1 to day 7 for subsequent cycles (dose escalation of 25% in each cycle in the absence of toxicity). Zoledronic acid was infused 4 mg iv on day 2. This dosing regimen is repeated every 28 days until disease progression. Adverse events were graded by NCI-CTCAE v4. Response was assessed by the modified International Uniform Response Criteria.Results and toxicity:42 patients (pts) have been enrolled with a median age of 59 (range 42-72); 50% were male and 50% female. All the 42 pts have received a median of 11 cycles (range 1-23). Of the 42 pts 21 remain on therapy (data at July 2016), 21 pts are off study: 9 due to progressive disease (PD) and 12 due to consent withdrawal. Among the 9 pts with PD, the median PFS post ASCT was 12 months (2-18 months). Of the 42 pts, 33 (79%) not progressed after a median of 13 months (range 1-33) and the median PFS has not been reached. 7/42 patients (17%) reached complete remission. Peripheral and bone marrow analysis of gamma delta lymphocytes expansion to evaluate the level of immune response is still under examination.Grade 1/2 hematologic adverse events (AEs) included: grade 1 (G1) anemia (3 pts), G1 neutropenia (3). Grade 1/2 drug-related non-hematologic AEs included: G1 fever (25) G2 fever (8); G2 constitutional symptoms (joint pains) (20); G2 constipation (4); G1/2 nausea (10); G1 fatigue (15), G1/2 cutaneous rash (2).Conclusions:Long term administration of combination of IL-2/zoledronate as maintenance therapy post ASCT is feasible. The incidence of non hematologic adverse events (in particular fever) were manageable with no dose escalation of IL-2 over 5 x 106UI. This immunological approach, without any chemotherapeutic drug, seems to be able to control the disease and to obtain the complete remission in a subgroup of myeloma patients. DisclosuresNo relevant conflicts of interest to declare.

Inhibitory mechanism of peptides with a repeating hydrophobic and hydrophilic residue pattern on interleukin-10

ABSTRACTInterleukin 10 (IL-10) is a cytokine that is able to downregulate inflammation. Its overexpression is directly associated with the difficulty in the clearance of chronic viral infections, such as chronic hepatitis B, hepatitis C and HIV infection, and infection-related cancer. IL-10 signaling blockade has been proposed as a promising way of clearing chronic viral infection and preventing tumor growth in animal models. Recently, we have reported that peptides with a helical repeating pattern of hydrophobic and hydrophilic residues are able to inhibit IL-10 significantly both in vitro and in vivo.1 In this work, we seek to further study the inhibiting mechanism of these peptides using sequence-modified peptides. As evidenced by both experimental and molecular dynamics simulation in concert the N-terminal hydrophobic peptide constructed with repeating hydrophobic and hydrophilic pattern of residues is more likely to inhibit IL10. In addition, the sequence length and the ability of protonation are also important for inhibition activity.

Abstract 4870: A novel potential target for cancer immunotherapy

Abstract Suppression of the host's immune system plays a major role in cancer progression. The tumor microenvironment (TME) not only plays a pivotal role during cancer progression and metastasis but also has profound effects on therapeutic efficacy. Immune checkpoint therapy, which targets regulatory pathways in T cells to enhance antitumor immune responses, has led to important clinical advances and provided a new weapon against cancer. This therapy has elicited durable clinical responses and, in a fraction of patients, long-term remissions. Several immune checkpoint inhibitors have been approved by the Food and Drug Administration (FDA), whose therapeutic effect is due to blocking the activity of proteins expressed in T lymphocytes (CTLA4, PD-1) and the interaction with surface protein expressed on tumor cells (PD-L1 and PD-L2). In our recent research activities we have identified 89 tumor-associated proteins by systematic immunohistochemistry analysis of tissue microarray (TMA) representing breast, colon, lung ovary and prostate cancer by using a large collection of polyclonal antibodies (approximately 1600) raised against membrane-associated and secreted proteins only marginally characterized. Among them, an interesting protein, which decorated the plasma membrane of breast cancer cells, was selected. This protein has been described to interact with the CD270/BTLA/CD160 pathway that regulates T-cell activation. It has also the capability to interfere with T-cell mediated allo-responses. Our characterization data showed that the protein is localized on the surface of several cancer cell lines. Moreover, it has the ability to stimulate cytokine production and secretion in PBMC from healthy donors. Several monoclonal antibodies have been generated in our lab against this protein and selected for the ability to bind the surface of cancer cells. Moreover, the ability of these monoclonal antibodies to interfere with the immune cells activity and to interfere with tumor growth in animal models is under evaluation. Results will be provided during the meeting. The currently approved therapeutic targets regimens for triple negative breast cancer and ovarian cancer have limited efficacy. Therefore, the identification of other tumor-associated proteins targetable by specific mAbs is essential to improve patient survival. Citation Format: Susanna Campagnoli, Matteo Parri, Alberto Grandi, Elisa De Camilli, Giuseppe Viale, Renata Maria Grifantini, Piero Pileri. A novel potential target for cancer immunotherapy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4870.

Effects of Gas1 on gliomas: a review on current preclinical studies

Effects of Gas1 on gliomas: a review on current preclinical studies Jose Segovia, Elizabeth Bautista, Manuel Lara-Lozano Departamento de Fisiologia, Biofisica y Neurociencias, Centro de Investigacion y de Estudios Avanzados del IPN, 07360 Distrito Federal, Mexico. Correspondence to: Dr. Jose Segovia, Departamento de Fisiologia, Biofisica y Neurociencias, Centro de Investigacion y de Estudios Avanzados del IPN, 07360 Distrito Federal, Mexico. E-mail: jsegovia@fisio.cinvestav.mx Glioblastoma multiforme (GBM) is the most common and lethal brain tumor. Its prognosis remains very poor, despite the use of combined treatments such as surgical resection, radiation and chemotherapy. The major limitations for the treatment of GBM are its high invasiveness, tumor recurrence and resistance to treatments. Therefore, gene therapy appears as a relevant strategy for its treatment. Thus, we have investigated the use of growth-arrest-specific 1 (Gas1) for the treatment of GBM. Gas1 is a tumor suppressor protein that inhibits glioma growth by inducing arrest and apoptosis of tumor cells. Moreover, we have shown that a soluble form of Gas1 acting in both autocrine and paracrine manners is also effective inhibiting tumor growth in animal models, indicating its potential as an adjuvant for the treatment of GBM.

Anticancer mechanisms of cannabinoids.

In addition to the well-known palliative effects of cannabinoids on some cancer-associated symptoms, a large body of evidence shows that these molecules can decrease tumour growth in animal models of cancer. They do so by modulating key cell signalling pathways involved in the control of cancer cell proliferation and survival. In addition, cannabinoids inhibit angiogenesis and decrease metastasis in various tumour types in laboratory animals. In this review, we discuss the current understanding of cannabinoids as antitumour agents, focusing on recent discoveries about their molecular mechanisms of action, including resistance mechanisms and opportunities for their use in combination therapy. Those observations have already contributed to the foundation for the development of the first clinical studies that will analyze the safety and potential clinical benefit of cannabinoids as anticancer agents.

Abstract A33: Expression of BRCA2 and Mir-21 in sporadic and BRCA2 mutated breast cancer in Iceland

Abstract The BRCA2 protein plays an important role in the repair of double-stranded DNA breaks (DSBs) by homologous recombination. An inherited founder mutation in the BRCA2 gene accounts for 6-7 % of all breast cancers in Iceland. Breast cancer in BRCA2 mutation carriers is associated with poor long-term prognosis. It has been reported that &amp;gt; 20% of sporadic breast cancers display a BRCA-like phenotype (BRCA‘ness), suggesting a defect in the DSB repair pathway. Little is known about the role of miRNAs in BRCA2 related breast cancer. Analysis of array CGH data from BRCA2 breast tumors shows that the mir-21 locus on chromosome 17 is amplified in &amp;gt; 70% of BRCA2 breast tumors. Mir-21 is a known oncomir with known target genes involved in tumor suppression, amongst others. High expression of mir-21 has been associated with poor-prognosis in other breast cancer populations. The aim of the study is to investigate the level and variation of BRCA2 and mir-21 expression in breast tumors from BRCA2 mutation carriers and breast tumors from non-carriers. Furthermore we want to see if there is association between BRCA2 and mir-21 expression. Expression analysis was performed by qPCR on RNA extracted from fresh frozen tumor tissue from BRCA2 mutation carriers and sporadic breast tumors. Expression of mir-21 was analyzed using specific mir-21 Taqman probes, with RNU48 as an endogenous control. Expression of BRCA2 was analyzed using gene specific primers detected by SYBR® Green, with HPRT1 as an endogenous control. To examine clinical relevance, we examine clinicopathological parameters including grade, nodal status, time to relapse and overall survival. Results from the BRCA2 expression analysis reveal significantly lower expression in the BRCA2 group compared to the sporadic group (as expected). However, BRCA2 expression shows a large degree of variation within both groups, with a greater than 20 fold difference between the highest and the lowest expression values. Results from the mir-21 expression analysis reveal a tendency towards a higher mir-21 expression in the BRCA2 group, although not statistically significant. When analyzing the BRCA2 and mir-21 expression data together we see a definite trend towards a negative correlation, where lower BRCA2 expression tends to associate with higher mir-21 expression. Our preliminary data thus show variability in BRCA2 expression, both among BRCA2 mutation carriers and non-carriers, as well as strong indications of negative association between BRCA2 and mir-21 expression. This information could be useful with respect to therapeutic strategies, e.g. making use of PARP inhibitors. Inhibitors targeting mir-21 have been shown to reduce tumor growth in animal models of multiple myelomas. The BRCA2 group shows high expression of mir-21 raising the possibility of using mir-21 inhibitors in patients with BRCA2 deficiency. Our results also indicate that mir-21 has an important role in BRCA2 carrier tumors as well as in sporadic cases. Note: This abstract was not presented at the conference. Citation Format: Sigridur Thora Reyisdottir, Sigridur Thora Reynisdottir, Olafur Andri Stefansson, Sigridur Klara Bödvarsdottir, Arnar Palsson, Jorunn Erla Eyfjörd. Expression of BRCA2 and Mir-21 in sporadic and BRCA2 mutated breast cancer in Iceland. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr A33.