Favor Tumor Growth Research Articles

Surgical peritoneal stress creates a pro-metastatic niche promoting resistance to apoptosis via IL-8

BackgroundThe mainstay of treatment of advanced ovarian cancer (AOC) involves chemotherapy, and debulking surgery. However, despite optimal surgical procedure and adjuvant chemotherapy, 60% of patients with AOC will relapse within 5 years. Most recurrences occur in the peritoneal cavity, suggesting the existence of occult sanctuaries where ovarian cancer cells (OCC) are protected. In murine models, surgical stress favors tumor growth; however, it has never been established that surgery may affect OCC sensitivity to subsequent chemotherapy. In this study, we investigated how the surgical stress could affect the chemosensitivity of OCC.MethodsTo avoid bias due to tumor burden in peritoneal cavity and duration of surgery, we used peritoneal biopsies from patients without a malignancy at precise time points. During laparotomies, peritoneal biopsies at the incision site were performed at the time of incision (H0 sample) and 1 h after initiation of surgery (H1 sample). We evaluated the chemoresistance to Taxol (0–20 µM) induced by H0 or H1 incubation (24 h) in two ovarian cancer cell lines OVCAR3 and SKOV3 and a primary cancer cell lines derived in our laboratory.ResultsOur results indicate that stressed peritoneum overexpressed cytokines, resulting in OCC increased resistance to therapy. Among these cytokines, IL8 was responsible for the resistance to apoptosis through the AKT pathway activation. Chemoresistance in OCC persists through the establishment of an autocrine IL8 loop. Finally, in a cohort of 32 patients, we showed an impact of IL8 tumoral overexpression on chemosensitivity and survival outcomes with a significant association to earlier recurrence.ConclusionsOur study demonstrated that precision surgery where targeted treatment would be used in combination with surgery is essential to obtain better tumor control.

Lactate dehydrogenase is correlated with clinical stage and grade and is downregulated by si‑STAB1 in ovarian cancer

Lactate, which is regulated by gene expression, is largely believed to favor tumor growth and survival. Elevated lactate dehydrogenase (LDH) is a negative prognostic biomarker because it is a key enzyme involved in cancer metabolism. Our previous study revealed that special AT‑rich‑binding protein1 (SATB1), a genome‑organizing protein, was strongly associated with high metastasis rates in ovarian cancer. However, its underlying molecular mechanisms in ovarian cancer are unclear. In the present study, we investigated whether SATB1 modulated LDH expression and examined the relationship between SATB1 and LDH in ovarian cancer. We employed transient siRNA‑mediated knockdown of SATB1 in ovarian cancer and explored the effects of this knockdown on the expression levels of key glucose metabolism‑related enzyme genes (G6PD, LDH, MDH1, PFK1 and TGM1) and the glucose metabolism‑related protein monocarboxylate transporter1 (MCT1). We comprehensively analyzed the cellular and molecular role of LDH in ovarian cancer to determine whether it could be a conventional clinicopathological parameter. SATB1 knockdown significantly downregulated both LDH and MCT1 levels and markedly upregulated BRCA1 and BRCA2 levels in ovarian cancer cells (P<0.05). Serum LDH levels in ovarian cancer patients were significantly higher than those in patients with benign ovarian tumors (P<0.05). LDH levels at different stages and grades differed significantly in ovarian cancer. Survival curves revealed that higher LDH expression was correlated with shorter survival (P<0.05). SATB1 may reprogram energy metabolism in ovarian cancer by regulating LDH and MCT1 levels to promote metastasis. Serum LDH levels presented diagnostic accuracy with high specificity and may have potential as a conventional clinicopathological parameter for ovarian cancer.

TRPS1 shapes YAP/TEAD-dependent transcription in breast cancer cells

Yes-associated protein (YAP), the downstream transducer of the Hippo pathway, is a key regulator of organ size, differentiation and tumorigenesis. To uncover Hippo-independent YAP regulators, we performed a genome-wide CRISPR screen that identifies the transcriptional repressor protein Trichorhinophalangeal Syndrome 1 (TRPS1) as a potent repressor of YAP-dependent transactivation. We show that TRPS1 globally regulates YAP-dependent transcription by binding to a large set of joint genomic sites, mainly enhancers. TRPS1 represses YAP-dependent function by recruiting a spectrum of corepressor complexes to joint sites. Loss of TRPS1 leads to activation of enhancers due to increased H3K27 acetylation and an altered promoter–enhancer interaction landscape. TRPS1 is commonly amplified in breast cancer, which suggests that restrained YAP activity favours tumour growth. High TRPS1 activity is associated with decreased YAP activity and leads to decreased frequency of tumour-infiltrating immune cells. Our study uncovers TRPS1 as an epigenetic regulator of YAP activity in breast cancer.

Abstract 1108: M2-polarized macrophages increase invasiveness of EBV-associated nasopharyngeal carcinoma by inducing invadopodia formation

Abstract Cancer metastasis is a major cause of mortality, accounting for approximately 90% of cancer related deaths. Emerging evidences suggest that tumour microenvironment plays an indispensable role in cancer metastasis. Recruitment of innate and adaptive immune cells to the tumour results in chronic inflammation which favours tumour growth and progression. Particularly, tumour associated macrophages (TAMs) are found to promote the initiation, growth, and metastasis in several types of cancers. Nasopharyngeal carcinoma (NPC) is one of the highly invasive and metastatic cancers and is closely associated with EBV infection. We postulate that TAMs may increase the invasiveness of NPC by enhancing the formation of invadopodia, which are membranous actin-rich protrusions with digestive ability of extra-cellular matrix. In this study, monocyte THP-1 cells were polarized to M2-macrophages, and co-cultured with nasopharyngeal cells in a contained chamber-insert. The stimulated nasopharyngeal cells then formed massive numbers of invadopodia and digested larger area of gelatin compared with the unstimulated counterparts. A cytokine antibody array was used to identify the upregulated cytokines in the co-culture medium of the M2-macrohphages and the NPC cells. Tumour necrosis factor alpha (TNFα) was revealed to be the responsible cytokine to induce the formation of invadopodia and digestion of gelatin. Besides, western blot analysis identified that several actin-associated proteins such as Src, Erk, and cortactin were involved in the TNFα-mediated invadopodia formation. We also found that the expression of latent membrane protein 1 (LMP1), an EBV protein that has similar structure to TNF receptor was elevated in NPC cells after co-culturing with the M2-polarized macrophages. Through transient transfection and stable expression of LMP1 in the NPC cells, LMP1 could also promote the formation of invadopodia through cdc42 activation. Taken together, these data indicate macrophages can promote the invasiveness of EBV-infected NPC cells by enhancing their ability in forming invadopodia through an activated TNFα signaling axis and LMP1 upregulation. Citation Format: Wilson Wing Chung Tang, Chan Ping You, Gareth E. Jones, George Sai-Wah Tsao, Anna Chi Man Tsang. M2-polarized macrophages increase invasiveness of EBV-associated nasopharyngeal carcinoma by inducing invadopodia formation [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 1108.

Targeting Oxidatively Induced DNA Damage Response in Cancer: Opportunities for Novel Cancer Therapies

Cancer is a death cause in economically developed countries that results growing also in developing countries. Improved outcome through targeted interventions faces the scarce selectivity of the therapies and the development of resistance to them that compromise the therapeutic effects. Genomic instability is a typical cancer hallmark due to DNA damage by genetic mutations, reactive oxygen and nitrogen species, ionizing radiation, and chemotherapeutic agents. DNA lesions can induce and/or support various diseases, including cancer. The DNA damage response (DDR) is a crucial signaling-transduction network that promotes cell cycle arrest or cell death to repair DNA lesions. DDR dysregulation favors tumor growth as downregulated or defective DDR generates genomic instability, while upregulated DDR may confer treatment resistance. Redox homeostasis deeply and capillary affects DDR as ROS activate/inhibit proteins and enzymes integral to DDR both in healthy and cancer cells, although by different routes. DDR regulation through modulating ROS homeostasis is under investigation as anticancer opportunity, also in combination with other treatments since ROS affect DDR differently in the patients during cancer development and treatment. Here, we highlight ROS-sensitive proteins whose regulation in oxidatively induced DDR might allow for selective strategies against cancer that are better tailored to the patients.

Co-chaperon p23 inhibitors: Identification of anticancer compounds from traditional Chinese medicine database

The heat shock protein 90 (Hsp90) is a molecular chaperon, which plays a vital action to favor tumor growth and metastasis among different types of cancers due to its significant role in stimulating the over-expression of anti-apoptotic proteins Hsp70 and Hsp27, which assist in the sustainable development of cancer cells. For the activation of the chaperoning activity, Hsp90 requires a small protein called co-chaperon p23. Recently, it has been reported that the binding of gedunin, a natural compound, with co-chaperon p23, inhibits p23 co-chaperoning activity through blocking its molecular interaction with Hsp90 and leads to cancer cell death by apoptosis. Hence, the above facts support the strong position of co-chaperon p23 as a potential therapeutic target for cancer treatment. In this study, we employed the virtual screening technique to explore the potent inhibitors of co-chaperon p23 from Traditional Chinese Medicine (TCM) database. Total 200 inhibitors from TCM against co-chaperon p23 were screened and only four TCM compounds like dihydro-n-caffeoyltyramine, lithospermic acid, oleuropein and salvianolic acid were selected for further analysis, which showed binding energies, −6.0, −6.6, −6.2 and −6.7kcal/mol, respectively. The findings of this study suggest that these TCM compounds can be considered as potent inhibitors of co-chaperon p23 for further in vitro and in vivo validation for designing new potential drugs for cancer treatment.

Lysyl oxidase-like 3 is required for melanoma cell survival by maintaining genomic stability

Lysyl oxidase-like 3 (LOXL3) is a member of the lysyl oxidase family comprising multifunctional enzymes with depicted roles in extracellular matrix maturation, tumorigenesis, and metastasis. In silico expression analyses followed by experimental validation in a comprehensive cohort of human cell lines revealed a significant upregulation of LOXL3 in human melanoma. We show that LOXL3 silencing impairs cell proliferation and triggers apoptosis in various melanoma cell lines. Further supporting a pro-oncogenic role in melanoma, LOXL3 favors tumor growth in vivo and cooperates with oncogenic BRAF in melanocyte transformation. Upon LOXL3 depletion, melanoma cells display a faulty DNA damage response (DDR), characterized by ATM checkpoint activation and inefficient ATR activation leading to the accumulation of double-strand breaks (DSBs) and aberrant mitosis. Consistent with these findings, LOXL3 binds to proteins involved in the maintenance of genome integrity, in particular BRCA2 and MSH2, whose levels dramatically decrease upon LOXL3 depletion. Moreover, LOXL3 is required for efficient DSB repair in melanoma cells. Our results reveal an unexpected role for LOXL3 in the control of genome stability and melanoma progression, exposing its potential as a novel therapeutic target in malignant melanoma, a very aggressive condition yet in need for more effective treatment options.

Neutrophils and Snail Orchestrate the Establishment of a Pro-tumor Microenvironment in Lung Cancer

Understanding the immune compartment of tumors facilitates the development of revolutionary new therapies. We used a Kras(G12D)-driven mouse model of lung cancer to establish an immune signature and identified a contribution of Gr1+ neutrophils to disease progression. Depletion experiments showed that Gr1+ cells (1) favor tumor growth, (2) reduce Tcell homing and prevent successful anti-PD1 immunotherapy, and (3) alter angiogenesis, leading to hypoxia and sustained Snail expression in lung cancer cells. In turn, Snail accelerated disease progression and increased intratumoral Cxcl2 secretion and neutrophil infiltration. Cxcl2 was produced mainly by neutrophils themselves in response to a factor secreted by Snail-expressing tumor cells. We therefore propose a vicious cycle encompassing neutrophils and Snail to maintain a deleterious tumor microenvironment.

BMP4 Induces M2 Macrophage Polarization and Favors Tumor Progression in Bladder Cancer.

Purpose: Bladder cancer is a current clinical and social problem. At diagnosis, most patients present with nonmuscle-invasive tumors, characterized by a high recurrence rate, which could progress to muscle-invasive disease and metastasis. Bone morphogenetic protein (BMP)-dependent signaling arising from stromal bladder tissue mediates urothelial homeostasis by promoting urothelial cell differentiation. However, the possible role of BMP ligands in bladder cancer is still unclear.Experimental Design: Tumor and normal tissue from 68 patients with urothelial cancer were prospectively collected and analyzed for expression of BMP and macrophage markers. The mechanism of action was assessed in vitro by experiments with bladder cancer cell lines and peripheral blood monocyte-derived macrophages.Results: We observed BMP4 expression is associated and favored type II macrophage differentiation. In vitro experiments showed that both recombinant BMP4 and BMP4-containing conditioned media from bladder cancer cell lines favored monocyte/macrophage polarization toward M2 phenotype macrophages, as shown by the expression and secretion of IL10. Using a series of human bladder cancer patient samples, we also observed increased expression of BMP4 in advanced and undifferentiated tumors in close correlation with epithelial-mesenchymal transition (EMT). However, the p-Smad 1,5,8 staining in tumors showing EMT signs was reduced, due to the increased miR-21 expression leading to reduced BMPR2 expression.Conclusions: These findings suggest that BMP4 secretion by bladder cancer cells provides the M2 signal necessary for a protumoral immune environment. In addition, the repression of BMPR2 by miR-21 makes the tumor cells refractory to the prodifferentiating actions mediated by BMP ligands, favoring tumor growth. Clin Cancer Res; 23(23); 7388-99. ©2017 AACR.

Proton beam irradiation inhibits the migration of melanoma cells.

PurposeIn recent years experimental data have indicated that low-energy proton beam radiation might induce a difference in cellular migration in comparison to photons. We therefore set out to compare the effect of proton beam irradiation and X-rays on the survival and long-term migratory properties of two cell lines: uveal melanoma Mel270 and skin melanoma BLM.Materials and methodsCells treated with either proton beam or X-rays were analyzed for their survival using clonogenic assay and MTT test. Long-term migratory properties were assessed with time-lapse monitoring of individual cell movements, wound test and transpore migration, while the expression of the related proteins was measured with western blot.ResultsExposure to proton beam and X-rays led to similar survival but the quality of the cell colonies was markedly different. More paraclones with a low proliferative activity and fewer highly-proliferative holoclones were found after proton beam irradiation in comparison to X-rays. At 20 or 40 days post-irradiation, migratory capacity was decreased more by proton beam than by X-rays. The beta-1-integrin level was decreased in Mel270 cells after both types of radiation, while vimentin, a marker of EMT, was increased in BLM cells only.ConclusionsWe conclude that proton beam irradiation induced long-term inhibition of cellular motility, as well as changes in the level of beta-1 integrin and vimentin. If confirmed, the change in the quality, but not in the number of colonies after proton beam irradiation might favor tumor growth inhibition after fractionated proton therapy.

Abstract 1092: PF562271, a Pyk2 inhibitor, reduces glioma tumor growth and invasion in C57Bl6-Gl261 mouse glioma model

Abstract Glioblastoma is an extraordinarily aggressive type of brain cancer due to its invasive and proliferative nature. The tumor microenvironment, with microglia as a critical player, has an important role in tumor progression. Microglia infiltrate majority of gliomas and release factors, which favor tumor growth and invasion. Previously we demonstrated that microglia residing within the tumor stimulate glioma cell invasion through the proline rich tyrosine kinase 2 (Pyk2) signaling cascade. We hypothesize that the use of pharmacological inhibitors of Pyk2 together with currently applied chemotherapy can significantly reduce invasiveness of glioblastoma tumor and improve the outcome of the treatment. Using C57Bl/6-Gl261 mouse glioma implantation model we investigated the effect of the combined treatment for glioblastoma with temozolomide (TMZ, 50 mg/kg, once/day, orally) together with a Pyk2 inhibitor PF562271 (twice/daily, 25 mg/kg, orally) vs. TMZ monotherapy. Treatment was provided during 14 days, beginning the 5th day after glioma implantation. For the assessment of the effectiveness of treatment animals’ survival, tumor size, and invasion area were evaluated. Western blot were used for the evaluation of the level of Pyk2 phosphorylation in tumor cells. For the purification of glioma cells from total tumor tissue Percol gradients were used. The study revealed that treatment with PF562271 reduced invasion of glioma cells at the tumor edge, while TMZ reduced the tumor growth. Combined treatment showed significantly more prominent effect on reduction of tumors growth compared to TMZ monotherapy and additionally reduced invasiveness of tumors similar to PF562271 monotherapy. In both PF562271 monotherapy and combined treatments the downregulation of Pyk2 phosphorylation in glioma cells has been recorded. Survival analysis demonstrated a significance increase of survival of animals received combined treatment compare to TMZ monotherapy. In conclusion, we can state that combined treatment with TMZ together with PF562271 reduced Pyk2-related tumor growth and invasiveness and increased animal survival. This research was made possible by NIH grant numbers: 1SC2GM102040, G12MD007583, R25GM110513, Puerto Rico Science, Technology, and Research Trust grant number 2016-00157, and US Department of Education Grant number P031S130068. Citation Format: Jescelica Ortiz-Rivera, Kimberleve Rolón-Reyes, Alejandro Albors, Luis Cubano, Lilia Kucheryavykh. PF562271, a Pyk2 inhibitor, reduces glioma tumor growth and invasion in C57Bl6-Gl261 mouse glioma model [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 1092. doi:10.1158/1538-7445.AM2017-1092

Abstract 1387: Target RNA sequencing revealed the expression profile of cancer genes in response to deacetylase inhibitor in primary culture of prostate cancer cells

Abstract Histone acetylation is a dynamic event to optimize cell functions through the control of RNA transcription and gene expression. In cancer, the histone deacetylation is a therapeutic target. Suppression of histone deacetylase increased the growth arrest, apoptosis, and senescence in cancer cells. Several histone deacetylase inhibitors (HDACis) have been developed and applied as a target therapy of various types of cancer, including the prostate cancer. However, the altered gene expression in HDACis treated prostate cancer cells is less reported. Little is known about the gene expression profiles of primary cultures of prostate cancer. In this study, we examined the cancer gene expression profile in primary cultures of human prostate cancer. Cells were isolated from two patient’s prostate cancer samples. Isolated cells were cultured in prostate epithelium culture medium CnT-52. After 24 hours of exposure to 400nM of Trichostatin A (TSA), an inhibitor of histone deacetylase I and II. RNA was extracted and quantified. The library was prepared with Illumina’s TruSight RNA Pan-Cancer Panel. The sequencing was performed on NextSeq 500 platform with NextSeq 500/550 mid output v2 kit (150cycles). FastQ files were generated by BaseSpace Onsite and analyzed further by TopHat alignment (Illumina) and Partek Flow (Partek). The Trusight RNA Pan-Cancer panel targets 1385 cancer genes and covers 21043 exonic regions with 57010 probes. The results showed that 59 of the 1385 cancer genes were significantly changed (FDR p-value&amp;lt;0.05, fold change &amp;gt;4 fold) in TAS treated cells. In the treated cells 49 genes were unregulated and 10 genes were down-regulated. The altered expression of 59 genes is involved in multiple cell functions. Genes that were upregulated included apoptosis associated genes (MAP2K6 and BIRC3), tumor suppression genes (DIRAS3, PEG3, PTPRO, and DNM3), and P53-target gene (CYFIP2). The genes that were down-regulated included cell cycle regulation genes (CDK1 and CCNA2), DNA damage response genes (BRCA1 and BRIP1), as well as cell proliferation marker Ki67 gene (MKI67). However, the gene expression response to TSA is complicated. Some altered gene expression favors tumor growth and progression while other gene expression changes inhibit tumor growth and promote apoptosis. In conclusion, we identified the gene profile in primary culture of prostate tumor in response to a histone deacetylase inhibitor, TSA. The therapeutic effects of HDACis could be influenced by the summation of contradicting tumor promoting and suppression gene expression profile changes. Citation Format: Hong Yin, Adam H. Greer, Glenn Mills. Target RNA sequencing revealed the expression profile of cancer genes in response to deacetylase inhibitor in primary culture of prostate cancer cells [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 1387. doi:10.1158/1538-7445.AM2017-1387

Increased incidence of liver cancer after successful DAA treatment of chronic hepatitis C: Fact or fiction?

Therapy of hepatitis C has been revolutionized by Direct Antiviral Agents. These drugs are safe and efficacious in all infected patients, including those with advanced, or decompensated cirrhosis, and are currently largely used in such cases in clinical practice worldwide. It was therefore cause of great concern the publication of two reports suggesting that treatment with DAAs could increase the risk of hepatocellular carcinoma in cirrhotic patients, particularly in those receiving antiviral therapy after having been cured for an HCC. These reports have generated a great and controversial debate and have been followed by a series of other publications not confirming such increased risk. This article summarizes published studies assessing the relation between DAA therapy and HCC in two different clinical setting: HCC recurrence in patients with an history of cured HCC and "de novo" HCC occurrence in patients without previous HCC. Rates of HCC recurrence after DAAs were extremely variable in different studies, reflecting great heterogeneity of this clinical setting. Data on "de novo" HCC incidence were more homogeneous and suggest that treatment with DAAs is not modifying the risk of developing HCC in the first 6-12months. The possibility that treatment with DAAs may favour tumour growth and spread in individual patients with active HCC foci is suggested by some observations but remains unproven. There is clearly a need for prospective studies designed to better define these issues.

Prevention of tumour cell apoptosis associated with sustained protein kinase B phosphorylation is more sensitive to regulation by insulin signalling than stimulation of proliferation and extracellular signal-regulated kinase

Insulin controls blood glucose while insulin-like growth factor (IGF) 1 is an important growth factor. Interestingly, both hormones have overlapping bioactivities and can activate the same intracellular signal transduction cascades. Growth control (mainly by IGF1) and metabolic function (predominantly by insulin) are believed to depend on activation of extracellular signal-regulated kinases (ERKs) 1/2 and protein kinase B (Akt/PKB), respectively. Therefore, insulin analogues that are used to normalize blood glucose are tested for their ability to preferentially activate Akt/PKB but not ERK1/2 and mitogenesis. Growth hormone, IGF1, and hyperinsulinemia are associated with increased risk of growth progression of some cancer types. To test if continuous exposure to insulin can favour tumour growth, we studied insulin/IGF1-dependent activation of ERK1/2 and Akt/PKB by Western blotting, inhibition of apoptosis by ELISA, and induction of proliferation by [3H]-thymidine incorporation in Saos-2/B10 osteosarcoma cells. IGF1 and insulin both induced proliferation and prevented apoptosis effectively. Regulation of apoptosis was far more sensitive than regulation of proliferation. IGF1 and insulin activated PKB (Akt/PKB) rapidly and consistently maintained its phosphorylation. Activation of ERK1/2 was only observed in response to IGF1. Loss of p-Akt/PKB (but not of p-ERK1/2) was associated with increased apoptosis, and protection from apoptosis was lost when activation of Akt/PKB was inhibited. These findings in Saos-2/B10 cells were also replicated in the A549 cell line, originally derived from a human lung carcinoma. Therefore, IGF1 and insulin more likely (at lower concentrations) enhance tumour cell survival than proliferation, via activation and maintenance of phosphatidylinositol 3-kinase activity and p-Akt/PKB.

Human breast adipose tissue: characterization of factors that change during tumor progression in human breast cancer

BackgroundAdipose microenvironment is involved in signaling pathways that influence breast cancer. We aim to characterize factors that are modified: 1) in tumor and non tumor human breast epithelial cell lines when incubated with conditioned media (CMs) from human breast cancer adipose tissue explants (hATT) or normal breast adipose tissue explants (hATN); 2) in hATN-CMs vs hATT-CMs; 3) in the tumor associated adipocytes vs. non tumor associated adipocytes.MethodsWe used hATN or hATT- CMs on tumor and non-tumor breast cancer cell lines. We evaluated changes in versican, CD44, ADAMTS1 and Adipo R1 expression on cell lines or in the different CMs. In addition we evaluated changes in the morphology and expression of these factors in slices of the different adipose tissues. The statistical significance between different experimental conditions was evaluated by one-way ANOVA. Tukey’s post-hoc tests were performed within each individual treatment.ResultshATT-CMs increase versican, CD44, ADAMTS1 and Adipo R1 expression in breast cancer epithelial cells. Furthermore, hATT-CMs present higher levels of versican expression compared to hATN-CMs. In addition, we observed a loss of effect in cellular migration when we pre-incubated hATT-CMs with chondroitinase ABC, which cleaves GAGs chains bound to the versican core protein, thus losing the ability to bind to CD44. Adipocytes associated with the invasive front are reduced in size compared to adipocytes that are farther away. Also, hATT adipocytes express significantly higher amounts of versican, CD44 and Adipo R1, and significantly lower amounts of adiponectin and perilipin, unlike hATN adipocytes.ConclusionsWe conclude that hATT secrete a different set of proteins compared to hATN. Furthermore, versican, a proteoglycan that is overexpressed in hATT-CMs compared to hATN-CMs, might be involved in the tumorogenic behavior observed in both cell lines employed. In addition, we may conclude that adipocytes from the tumor microenvironment show a less differentiated state than adipocytes from normal microenvironment. This would indicate a loss of normal functions in mature adipocytes (such as energy storage), in support of others that might favor tumor growth.

Exploiting Microglial Functions for the Treatment of Glioblastoma.

Glioblastoma multiforme (GBM) is the most common brain tumor in adults and is associated with a very low survival rate. The heterogeneity of the tumor microenvironment, its resistance to drug and radiation therapy, and its robust invasiveness all contribute to the poor outcome. Large numbers of glioma associated microglia and macrophages (GAMs) can accumulate within the tumor where they appear to have an important role in prognosis. An extensive revision of current available literature on this topic has been carried out, using the PubMed database. Articles exploring the contribution of GAMs to GBM biology as well as evidence that GAMs can be pharmacologically modulated to inhibit tumor growth are critically discussed in this review article. GAMs constitute the largest portion of tumor infiltrating cells contributing up to 30% of the entire glioma mass. Upon interaction with neoplastic cells, GAMs acquire a unique phenotype of activation including both M1 and M2 specific markers. Different profiles of activation usually co-exist in the same tumor that is dependent upon GAM location or stage of disease. In addition to regulating immune responses which may control or favor astrocyte malignant transformation, GAMs are directly involved in the degradation of the extracellular matrix (ECM), a crucial mechanism that allows the expansion of tumors and parenchyma invasion. Several pharmacological strategies have been developed which interfere with GAM recruitment at the tumor site, cell polarization and immune function, and ECM remodeling by GAM-secreted factors. The most promising therapeutic approaches appear to target both GBM cells and GAM biological properties. GAMs significantly contribute to GBM biology (favoring tumor growth and invasiveness). Data reviewed in the present article suggest that these cells represent a valuable alternative/ additional target for the development of more effective treatments for GBM.

Caveolin 1 expression favors tumor growth and is associated with poor survival in primary lung adenocarcinomas.

Despite the consolidated clinico-pathological correlates of Caveolin 1 expression in non-small cell lung cancer, the available data on the role of Caveolin 1 in relation to proliferation, migration, and metastasis in lung adenocarcinoma cells is still scant. Here, we aimed to confirm whether Caveolin 1 may act as a promoter of cell growth in human lung adenocarcinoma using in vitro and in vivo models, supported by a survival analysis of Caveolin 1 expression in a series of 116 primary lung adenocarcinomas. The silencing of endogenous Caveolin 1 expression in H522 lung adenocarcinoma cells through stable shRNA transfection significantly inhibited cellular proliferation in vitro and in vivo, in a lung adenocarcinoma xenograft mouse model. The bioluminescence imaging analysis revealed that tumors derived from Caveolin 1 shRNA-transfected cells grew slower than control xenografts. However, this difference progressively diminished over time and was definitively lost after 21 days. This was consistent with a progressive Caveolin 1 re-expression, which started at day 7. The association between the restored expression of Caveolin 1 and the restart of tumor growth in vivo supports the booster role of Caveolin 1 in lung adenocarcinoma progression. To further confirm this role, Caveolin 1 expression was assessed by immunohistochemistry in a series of 116 human lung adenocarcinomas. Positive Caveolin 1 tumors accounted for 20% of cases and were associated with a significantly worse overall survival compared to Caveolin 1-negative cancers. Taken together, these data highlight that Caveolin 1 expression confers a proliferative advantage in lung adenocarcinoma cells, thus fostering increased tumor aggressiveness.

Mesenchymal Stem Cell-Derived Extracellular Vesicles: Roles in Tumor Growth, Progression, and Drug Resistance.

Mesenchymal stem cells (MSCs) are ubiquitously present in many tissues. Due to their unique advantages, MSCs have been widely employed in clinical studies. Emerging evidences indicate that MSCs can also migrate to the tumor surrounding stroma and exert complex effects on tumor growth and progression. However, the effect of MSCs on tumor growth is still a matter of debate. Several studies have shown that MSCs could favor tumor growth. On the contrary, other groups have demonstrated that MSCs suppressed tumor progression. Extracellular vesicles have emerged as a new mechanism of cell-to-cell communication in the development of tumor diseases. MSCs-derived extracellular vesicles (MSC-EVs) could mimic the effects of the mesenchymal stem cells from which they originate. Different studies have reported that MSC-EVs may exert various effects on the growth, metastasis, and drug response of different tumor cells by transferring proteins, messenger RNA, and microRNA to recipient cells. In the present review, we summarize the components of MSC-EVs and discuss the roles of MSC-EVs in different malignant diseases, including the related mechanisms that may account for their therapeutic potential. MSC-EVs open up a promising opportunity in the treatment of cancer with increased efficacy.

Immunotherapy in NSCLC: A Promising and Revolutionary Weapon.

Lung cancer is the leader malignancy worldwide accounting 1.5 millions of deaths every year. In the United States the 5 year-overall survival is less than 20% for all the newly diagnosed patients. Cisplatin-based cytotoxic chemotherapy for unresectable or metastatic NSCLC patients in the first line of treatment, and docetaxel in the second line, have achieved positive results but with limited benefit in overall survival. Targeted therapies for EGFR and ALK mutant patients have showed better results when compared with chemotherapy, nevertheless most of patients will fail and need to be treated with chemotherapy if they still have a good performance status.Immunotherapy recently has become the most revolutionary treatment in solid tumors patients. First results in unresectable and metastatic melanoma patients treated with an anti CTLA-4 monoclonal antibody showed an unexpected 3-year overall survival of at least 25%.Lung cancer cells have multiple immunosuppressive mechanisms that allow to escape of the immune system and survive, however blocking CTLA-4 pathway with antibodies as monotherapy treatment have not achieved same results than in melanoma patients. PD-1 expression has been demonstrated in different tumor types, suggesting than PD-1 / PD-L1 pathway is a common mechanism used by tumors to avoid immune surveillance and favoring tumor growth. Anti PD-1 and anti PD-L1 antibodies have showed activity in non-small cell lung cancer patients with significant benefit in overall survival, long lasting responses and good safety profile, including naïve and pretreated patients regardless of the histological subtype. Even more, PD-1 negative expression patients achieve similar results in overall survival when compared with patients treated with chemotherapy. In the other side high PD-1 expression patients that undergo immunotherapy treatment achieve better results in terms of survival with lesser toxicity. Combining different immunotherapy treatments, combination of immunotherapy with chemotherapy or with targeted treatment are under research with some promising PRELIMINARY results in non-small cell lung cancer patients.This chapter attempts to summarize the development of immunotherapy treatment in non-small cell lung cancer patients and explain the results that have leaded immunotherapy as a new standard of treatment in selected NSCLC patients.

Vascular mimicry in glioblastoma following anti-angiogenic and anti-20-HETE therapies

Glioblastoma (GBM) is one hypervascular and hypoxic tumor known among solid tumors. Antiangiogenic therapeutics (AATs) have been tested as an adjuvant to normalize blood vessels and control abnormal vasculature. Evidence of relapse exemplified in the progressive tumor growth following AAT reflects development of resistance to AATs. Here, we identified that GBM following AAT (Vatalanib) acquired an alternate mechanism to support tumor growth, called vascular mimicry (VM). We observed that Vatalanib induced VM vessels are positive for periodic acid-Schiff (PAS) matrix but devoid of any endothelium on the inner side and lined by tumor cells on the outer-side. The PAS+ matrix is positive for basal laminae (laminin) indicating vascular structures. Vatalanib treated GBM displayed various stages of VM such as initiation (mosaic), sustenance, and full-blown VM. Mature VM structures contain red blood cells (RBC) and bear semblance to the functional blood vessel-like structures, which provide all growth factors to favor tumor growth. Vatalanib treatment significantly increased VM especially in the core of the tumor, where HIF-1α was highly expressed in tumor cells. VM vessels correlate with hypoxia and are characterized by co-localized MHC-1+ tumor and HIF-1α expression. Interestingly, 20-HETE synthesis inhibitor HET0016 significantly decreased GBM tumors through decreasing VM structures both at the core and at periphery of the tumors. In summary, AAT induced resistance characterized by VM is an alternative mechanism adopted by tumors to make functional vessels by transdifferentiation of tumor cells into endothelial-like cells to supply nutrients in the event of hypoxia. AAT induced VM is a potential therapeutic target of the novel formulation of HET0016. Our present study suggests that HET0016 has a potential to target therapeutic resistance and can be combined with other antitumor agents in preclinical and clinical trials.