Tumor Proliferation Rate Research Articles

Abstract B31: Characterization of a novel model of prostate cancer metastasis resulting from androgen receptor suppression

Abstract Background: Prostate cancer (PC) is the second leading cause of male cancer-related mortality: 30,000 men die each year from metastatic disease. The Androgen Receptor (AR) may be the earliest known example of a lineage oncogene – a master regulator of prostate cancer cell survival and growth. The AR protein is detectable at all stages of prostate cancer progression and is the primary target of pharmacological agents capable of suppressing AR signaling to extend survival in men with metastatic prostate cancer (mPC). The CYP17 inhibitor Abiraterone, and the 3rd generation AR antagonist, MDV3100 prolong the survival of men with mPC, though cures remain exceeding rare using these agents individually. In order to develop additional therapies to be used in combination with current AR inhibitors, preclinical models that mimic PC progression need to be established. Tissue microarray studies from hormone-naïve, nodal positive, prostate cancer patients revealed a significant down-regulation of AR protein level in matched nodal metastases versus primary tumors. These results suggest that loss of AR or AR activity could play a role in the progression to metastatic disease. Methods: We used a short-hairpin RNA targeting exon 1 of the AR to reduce AR protein in vivo using a doxycycline-inducible system in the non-metastatic AR-positive human prostate cancer cell line 22Rv1. This cell line model, derived from a primary tumor, is castration-resistant and enzalutamide/MDV3100-resistant. We generated xenografts using 22Rv1shARex1 and evaluated tumor growth and propensity for metastatic spread. We profiled transcriptional changes in the context of AR suppression and compared gene expression changes between grafted tumors and sites of metastatic spread. Results: Xenograft studies in NOD-SCID mice revealed that reduction of the AR protein decreased tumor proliferation rates and promoted cancer metastasis. Tumor-bearing mice exposed to continual reduction of the AR developed large liver metastases and had significantly increased disseminated tumor cells in their bone marrow. Furthermore, intratibial and intracardiac injection of 22Rv1shARex1 followed by AR reduction, resulted in an increased formation of metastases. Transcriptional analysis revealed unique signatures between untreated parental 22Rv1 xenografts, tumors with AR reduction, and liver metastases. Genes up-regulated in xenografts following AR reduction, were also up-regulated in patient metastases versus primary tumors including transcripts encoding EGF, HGF, and ZEB2. Discussion: The AR is the primary therapeutic target for mPC. However, a cure for advanced cancer and metastatic disease remains elusive. Reduction of the AR in the 22Rv1 in vivo model mimics disease progression seen in patients. Molecular changes observed during the transformation of localized cancer to metastatic disease in this model may identify new targets to be used in combination with current therapies intent on ablating AR signaling. Citation Format: Clinton K. Matson, Peter S. Nelson. Characterization of a novel model of prostate cancer metastasis resulting from androgen receptor suppression. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Metastasis; 2015 Nov 30-Dec 3; Austin, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(7 Suppl):Abstract nr B31.

Synergistic and attenuated effect of HSS in combination treatment with docetaxel plus cisplatin in human non-small-cell lung SPC-A-1 tumor xenograft.

Platinum based combination regimens are first-line treatment option in treatment of non-small cell lung cancer (NSCLC) but the clinical utility has been limited because of their toxicities. Many reports indicated that patients with tumors can benefit from adjuvant chemotherapy drugs. The aim of this study was to confirm adjuvant chemotherapy of HSS with docetaxel plus cisplatin (DP) against NSCLC by evaluating antitumor activity and attenuated effect. In vivo SPC-A-1 xenograft model was established to evaluate antitumor activity and toxicity of HSS along or combination with DP. Evaluation indexes include the relative tumor proliferation rate, tumor growth inhibition rate, body weight, food consumption, hematological and biochemical analysis. HSS treatment showed inhibited tumor growth and increased tumor inhibition of DP treatment at doses of 250 mg/kg and 500 mg/kg. No significant toxicity was found in HSS-treated mice, but significant toxicity was found in DP-treated mice. HSS combination with DP could reduce toxicity of DP treatment by improving body weight and food consumption, and increasing the number of WBC and PLT, decreasing the level of ALT, AST and BUN. HSS combined with DP treatment has additive effect which contributes to enhance tumor growth inhibition of DP treatment and attenuated effect which contributes to reduce toxicity of DP treatment. These findings indicate potential benefit for use of HSS adjuvant chemotherapy for NSCLC treatment.

Quercetin-loaded nanomicelles to circumvent human castration-resistant prostate cancer in vitro and in vivo.

Prostate cancer is highly prevalent and has become the second leading cause of cancer-related death in men. Its treatment remains a challenge in the clinic, particularly in patients who have advanced to "castration-resistant prostate cancer" (CRPC). Thus, more effective therapeutic strategies are required. Quercetin (QCT) is a natural flavonoid compound that has attracted increasing interest due to its anticancer activity. However, the clinical application of quercetin is largely hampered by its poor water solubility and low bioavailability. The objective of this study was to evaluate the therapeutic potential of novel QCT-loaded nanomicelles (M-QCTs) assembled from DSPE-PEG2000 for prostate cancer treatment. Our results indicated that QCT was efficiently encapsulated into micelles up to 1 mg mL(-1), which corresponds to a 450-fold increase of its water solubility. In vitro studies showed that the half-maximal inhibitory concentration (IC50) value (20.2 μM) of M-QCTs was much lower than free QCT (>200 μM). Thus, M-QCTs were considerably more effective than free QCT in proliferation inhibition and apoptosis induction of human androgen-independent PC-3 cells. Furthermore, M-QCTs showed superior antitumor efficacy and the tumor proliferation rate reduced by 52.03% compared to the control group in the PC-3 xenograft mouse model, possibly due to increased accumulation of M-QCTs at the tumor site by the enhanced permeability and retention (EPR) effect. Collectively, our studies demonstrated that M-QCTs significantly increase drug accumulation at the tumor site and exhibit superior anticancer activity in prostate cancer. Thus, our nanomicelle-based drug delivery system constitutes a promising and effective therapeutic strategy for clinical treatment.

Fluorine-18-Labeled Thymidine Positron Emission Tomography (FLT-PET) as an Index of Cell Proliferation after Pharmacological Ascorbate-Based Therapy.

Pharmacological ascorbate (AscH(-)) induces cytotoxicity and oxidative stress selectively in pancreatic cancer cells compared with normal cells. Positron emission tomography (PET) with the thymidine analog 3'-deoxy-3'-((18)F) fluorothymidine (FLT) enables noninvasive imaging and quantification of the proliferation fraction of tumors. We hypothesized that the rate of tumor proliferation determined by FLT-PET imaging, would be inversely proportional to tumor susceptibility to pharmacological AscH(-)-based treatments. Indeed, there was decreased FLT uptake in human pancreatic cancer cells treated with AscH(-) in vitro, and this effect was abrogated by co-treatment with catalase. In separate experiments, cells were treated with AscH(-), ionizing radiation or a combination of both. These studies demonstrated that combined AscH(-) and radiation treatment resulted in a significant decrease in FLT uptake that directly correlated with decreased clonogenic survival. MicroPET (18)F-FLT scans of mice with pre-established tumors demonstrated that AscH(-) treatment induced radiosensitization compared to radiation treatment alone. These data support testing of pharmacological ascorbate as a radiosensitizer in pancreatic cancer as well as the use of FLT-PET to monitor response to therapy.

Effect of recombinant human endostatin onradiotherapy for esophagus cancer.

To investigate the effect of radiotherapy plus recombinant human endostatin (RH-endostatin) on esophageal cancer and its mechanism. A total of 50 nudemice were equally randomized into control group, radiotherapy group, and combined therapy group I, II, and III after inoculating with Eca109 cell suspension (1×10(7)cells/mL). On the day of grouping, control group and radiotherapy group were injected normal saline, while radiotherapy group and 3 combined therapy groups received radiotherapy; besides, combined therapy group I, II, and III was injected RH-endostatin of 2.5, 5, 10mg/kg respectively. After 3-week therapy, the tumors of each group were collected and microvessel density and VEGF expression in tumors were determined. Invitro, Eca109 cells were divided into control group, radiotherapy group, and combined therapy group. Forty-eight hours after treatment, cell cycle distribution and apoptosis rate were detected, and the activity of VEGF signal paths was semiquantitatively analyzed. Since the 6th day of treatment, the relative tumor proliferation rate of combined therapy group II was lower than radiotherapy group (P<0.05) and ≤40% since the 15th day. Average microvessel density and EGFR expression in combined therapy group II were lower than radiotherapy group (P<0.05). Invitro, the cell percentage in S and G2/M phase of combined therapy group cells was lower than that in radiotherapy group cells, while the apoptosis rate and the expression of VEGF, AKT, p-AKT, ERK1/2 and p-ERK1/2 in combined group were higher than that in radiotherapy group (P<0.05). RH-endostatin promotes the efficacy of radiotherapy on esophageal cancer, which may be partly realized by inhibiting the activity of VEGF related signal paths.

A comparative study of proliferative activity and tumor stage of pregnancy-associated melanoma (PAM) and non-PAM in gestational age women

The influence of pregnancy on the development, progression, and prognosis of melanoma is controversial. We sought to compare clinical characteristics, histologic features, and proliferative activity in pregnancy-associated melanoma (PAM) and melanoma in nonpregnant women of reproductive age (non-PAM). In this retrospective cohort study, we reviewed medical records and pathology reports from women given a diagnosis of melanoma between 2006 and 2015. We also examined tumor proliferation rates using mitotic count and 2 immunohistochemical markers of proliferation, phosphohistone H3 and Ki-67. In 50 PAM and 122 non-PAM cases, a diagnosis of melanoma in situ was associated with PAM. Among invasive melanomas, there was no difference in proliferative activity between groups. Pregnancy status was also not associated with age at diagnosis, tumor site, Breslow depth, Clark level, ulceration, or overall stage. This was a retrospective study with a small sample size of mostly patients with early-stage melanoma. In our study of primarily early-stage melanoma, pregnancy did not have a significant impact on tumor proliferation. Particularly for patients given a diagnosis of stage I melanoma who are undergoing close surveillance, a history of PAM should not outweigh traditional factors, such as advanced maternal age, in planning future pregnancies.

ATPS-21MONITORING OF LOCAL TREATMENT EFFECTS WITH TEMOZOLOMIDE IN AN ORTHOTOPIC MURINE GLIOBLASTOMA MODEL

INTRODUCTION: Locally administered agents against malignant gliomas demand sophisticated metabolic imaging to monitor local and systemic treatment effects in animal models. The purpose of this feasibility study was to create an animal model suitable to represent the effect of locally delivered, soluble temozolomide in orthotopically implanted gliomas using micro-[18F] FLT-PET for high quality metabolic information with a distinct resolution for observation of treatment effects. METHODS: U87 glioma cells were stereotactically implanted in 48 female T-cell deficient athymic nude rats (RNU). Tumor existence and proliferation was proven by [18F] FLT-PET and microMRI. Rats were allocated to four treatment groups. Group one and two received a one-time intratumoral stereotactic injection of soluble temozolomide (TMZ) (group 1: 0.03mg; group 2: 0.015mg). Group three was administered systemic TMZ for 2 days (5mg). Group four served as untreated control group. Treatment was performed on day 15 post implantation. FLT-PET and MRI were performed 7 and 14 days after treatment. Animals showing signs of neurological impairment or reduced general health were immediately examined by MRI and sacrificed according to the animal ethical guidelines. RESULTS: The tumor take rate was 100 percent. Characteristically, U87 tumor cell formation was rather solid. Tumor size (MRI) and proliferation rate (PET) were congruent in all groups prior to treatment. Post treatment, FLT-PET was more specific for tumor growth compared to MRI. Tumor proliferation rates were significantly lower in the local treatment groups. MRI confirmed intratumoral TMZ fluid distribution which decreased within 7 days. CONCLUSION: Our orthotopic rat glioma model proved to be feasible and efficient for the performance of local therapy studies. Sophisticated Micro-PET offers distinct monitoring of tumor proliferation and supplements MR tumor imaging very well. The FLT-PET tracer is most suitable for the monitoring of local treatment effects of TMZ.

IMPS-12CCR2 DEFICIENCY REDUCES THE INFLUX OF CD11b+ MACROPHAGES IN MURINE GLIOMAS

INTRODUCTION: Glioblastomas (GBMs) are characterized by behavioral aggressiveness and a dismal prognosis despite multimodality therapies. While high numbers of microglia/macrophages are found within GBM, little is known of their specific function within this microenvironment. Mounting evidence indicates a role for these cells in tumor progression and therapy resistance. Microglia/macrophages can constitute as high as 30% of total cells within GBM and there is evidence for the positive correlation between numbers of infiltrating microglia/macrophages and tumor proliferation rate. Sources of these mononuclear cells include brain parenchyma (microglia) and bone marrow (BM). Despite the potential significance of GBM-associated microglia/macrophages to tumor progression and decreased therapeutic efficacy, the mechanisms by which these cells infiltrate GBM are unknown. This localization likely requires the presence of chemokines within the tumor microenvironment and their cognate receptors expressed on microglia/macrophages. While brain-derived microglia and BM-derived macrophages share similar characteristics they also likely exert distinct functions within, and utilize unique mechanisms to gain access to, the GBM microenvironment. It is reported that peripheral BM-derived pro-inflammatory mononuclear cells express the chemokine receptor CCR2 and traffic into inflamed tissues, including irradiated adult brain, in a CCR2-dependent manner. OBJECTIVE: Understand the role of CCR2 in macrophage function within GBM, with the long term goal of inhibiting the pro-tumor promoting activities of these cells. METHODS: We performed immunohistochemical analyses of human GBM sections and analyzed the presence of CCR2+CD11b+ macrophages in CCR2-sufficient and -deficient GL261- and KR158-glioma bearing mice. RESULTS: GBM-associated CD68+ macrophages express CCR2. Prominent numbers of CCR2+CD11b+ macrophages were found within murine GL261 and KR158 gliomas that were distinct from CX3CR1+CD11b+ cells. The tumor localization of the former cells was greatly reduced in CCR2-deficient mice. CONCLUSION: Blocking CCR2 could impact the presence of GBM-associated macrophages, which may in turn decrease tumor growth and/or augment the efficacy of current treatments.

MTH1 counteracts oncogenic oxidative stress.

MTH1 counteracts oncogenic oxidative stress.

Strategies for developing Ki67 as a useful biomarker in breast cancer

Increased proliferation is a hallmark of malignant tumors. The proliferation marker Ki67 has been investigated as a breast cancer biomarker, but despite 32 years of research the best cutpoints and the best methods for determination are still under debate. This review is based on an overview on the efforts to standardize Ki67 and to optimize its performance that was presented at the St. Gallen oncology conference 2015. The clinical validity of Ki67 as a prognostic marker as well as a predictive marker (in the neoadjuvant setting) has been shown in several meta-analyses. Depending on cohort characteristics, molecular subtype and clinical setting, Ki67 is a prognostic marker, a predictive marker, or both. Many different cutpoints for Ki67 have been reported, but it is has not been possible to determine an evidence-based “optimal” cutpoint. This supports the view that Ki67 is continuous marker, reflecting the continuous variation of the proliferation rate in different tumors. We should probably stop looking for an “optimal” cutpoint for Ki67 because it simply does not exist.It is evident from the results of several ring trials that intermediate levels of Ki67 are particularly difficult for standardization. Due to the low analytical validity in the intermediate range as well as intratumoral heterogeneity, the clinical utility of intermediate Ki67 levels is limited. Clinical decisions should not be based on small differences in the intermediate range and additional molecular tests might be necessary for tumors with intermediate Ki67 levels. For the two groups of tumors with a very low or a very high Ki67 a clinical interpretation could be straightforward.Despite these limitations, the assessment of proliferation is a central parameter for tumor characterization and an important element of the pathological assessment.

Abstract 3492: Metformin inhibits salivary gland tumor growth through cell cycle arrest and apoptosis

Abstract Human salivary gland cancer (SGC) is one of the common malignancies found in the head and neck area. The limitation of the treatment and poor prognosis are calling for more investigations into novel intervention to improve the treatment modality in SGCs. Metformin as a widely used anti-type-2 diabetes medicine had demonstrated its anti-tumor potential in many different types of cancers. Our previous work demonstrated that metformin effectively targeted c-Myc oncogene to prevent the initiation and progression of prostate cancer. Interestingly, the overexpression of c-Myc has also been shown in some SGCs, such as salivary gland adenoid cystic carcinoma. Therefore, it is intriguing to explore metformin's anti-neoplastic efficacy of metformin in SGC. In this study, we used a human salivary adenocarcinoma cell line, HSY cell line as a model for salivary gland tumor. Our in vitro results show metformin prominently suppresses the growth of HSY cell through stimulation of cell cycle arrest and apoptosis. Meanwhile, metformin significantly down-regulates cMyc expression and rescues p53 tumor suppressor gene expression. Considering that mTOR inhibitors resistance could occur when tumors over-express cMYC. PP242, a novel and potent mTOR inhibitor was used in combination with metformin to inhibit HSY cell growth. As expected, metformin enhanced the inhibitory effects of PP242 associated with reduced c-MYC levels in vitro. Further in HSY xenograft tumors, massive necrotic areas were observed inside the tumors from metformin treated mice while only limited necrotic area in the core of tumors from PBS treated mice. Staining of proliferation marker Ki-67 confirmed lower proliferation rate in tumors from metformin treated group compare to that from the PBS group. In conclusion, our novel finding of metformin efficacy in SGC not only proves metformin plays a pivotal role in suppressing SGCs through cell cycle arrest and apoptosis, but also suggest that a combination treatment using metformin and mTOR inhibitors together may yield better inhibitory efficacy. Citation Format: Yuqi Guo. Metformin inhibits salivary gland tumor growth through cell cycle arrest and apoptosis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3492. doi:10.1158/1538-7445.AM2015-3492

Abstract 2363: Loss of Sparc in p53-null astrocytes alters collagen deposition and promotes macrophage activation and tumor phagocytosis

Abstract Both the induction of SPARC expression and the loss of the p53 tumor suppressor gene are changes that occur early in glioma development. Therefore, the upregulation of SPARC may cooperate with the loss of p53 to enhance cell survival and inhibit apoptosis during glioma formation. This study determined whether the loss of Sparc in astrocytes that are null for p53 (p53-null/Sparc-null) would result in reduced cell survival and tumor formation and increased tumor immunogenicity in an in vivo xenograft brain tumor model. In vitro, the loss of Sparc in p53-null astrocytes resulted in an increase in cell proliferation (15-33%, p&amp;lt;0.01); however, there was an inhibition of growth in soft agar. Intracranial xenografts of p53-null/Sparc-wt and p53-null/Sparc-null astrocytes were assessed for tumor size, proliferation rate, and SPARC expression. At 7 days post-implantation, Sparc-null astrocytes produced significantly smaller tumors (Wilcoxon rank-sum test p = 0.0091, median = 0.709mm2 for Sparc-wt and 0.240mm2 for Sparc-null) with a significantly lower MIB-1 proliferation index (Wilcoxon rank-sum test p = 0.0345, median = 8.6% for Sparc-wt and 0.4% for Sparc-null). By CD68 and periodic acid Schiff +/- diastase staining of xenograft tumors, it was found that Sparc-null tumors had a massive infiltration of microglia/macrophages with a phagocytic appearance compared to the activated, but non-phagocytic, microglia/macrophages present within the Sparc-wt tumors. The loss of Sparc in astrocytes and the resulting increase in microglia/macrophage activation lead to an alteration in the tumor microenvironment with increased collagen deposition and altered collagen structure at both 7 and 50 days post-implantation as assessed by picrosirius red and polarized light microscopy. Sparc-null tumors had increased collagen deposition with a long fiber structure compared to the small bundles of collagen present in Sparc-wt tumors. Our results indicate that the loss of p53 by deletion/mutation in the early stages of glioma formation may cooperate with the induction of SPARC to potentiate cancer cell survival and escape from immune surveillance. Citation Format: Stacey L. Thomas, Chad R. Schultz, Ezekiell Mouzon, William A. Golembieski, Nancy Lemke, Laila M. Poisson, Jorge A. Gutierrez, Sandra Cottingham, Sandra A. Rempel. Loss of Sparc in p53-null astrocytes alters collagen deposition and promotes macrophage activation and tumor phagocytosis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2363. doi:10.1158/1538-7445.AM2015-2363

Clinicopathological Features and Prognosis of Metaplastic Breast Carcinoma: Experience of a Major Chinese Cancer Center.

Metaplastic breast carcinoma (MBC) is a rare heterogeneous group of primary breast malignancies, with low hormone receptor expression and poor outcomes. To date, no prognostic markers for this tumor have been validated. The current study was undertaken to evaluate the clinicopathologic characteristics, the response to various therapeutic regimens and the prognosis of MBCs in a large cohort of patients from Tianjin Medical University Cancer Hospital in China. Ninety cases of MBCs diagnosed in our hospital between January 2000 and September 2014 were retrieved from the archives. In general, MBCs presented with larger size, a lower rate of lymph node metastasis, and demonstrated more frequent local recurrence/distant metastasis than 1,090 stage-matched cases of invasive carcinoma of no specific type (IDC-NST), independent of the status of estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 expressions. The five-year disease-free survival (DFS) of MBC was significantly worse than IDC-NST. Using univariate analysis, lymph node metastasis, advanced clinical stage at diagnosis, high tumor proliferation rate assessed by Ki-67 labeling, and epidermal growth factor receptor (EGFR) overexpression/gene amplification were associated significantly with reduced DFS, while decreased OS was associated significantly with lymph node metastasis and EGFR overexpression/gene amplification. With multivariate analysis, lymph node status was an independent predictor for DFS, and lymph node status and EGFR overexpression/gene amplification were independent predictors for OS. Histologic subtyping and molecular subgrouping of MBCs were not significant factors in prognosis. We also found that MBCs were insensitive to neoadjuvant chemotherapy, routine chemotherapy, and radiation therapy. This study indicates that MBC is an aggressive type of breast cancer with poor prognosis, and that identification and optimization of an effective comprehensive therapeutic regimen is needed.

Radial expansion rates and tumor growth kinetics predict malignant transformation in contrast-enhancing low-grade diffuse astrocytoma.

Contrast-enhancing low-grade diffuse astrocytomas are an understudied, aggressive subtype at increased risk because of few radiographic indications of malignant transformation. In the current study, we tested whether tumor growth kinetics could identify tumors that undergo malignant transformation to higher grades. Thirty patients with untreated diffuse astrocytomas (WHO II) that underwent tumor progression were enrolled. Contrast-enhancing and T2 hyperintense tumor regions were segmented and the radius of tumor at two time points leading to progression was estimated. Radial expansion rates were used to estimate proliferation and invasion rates using a biomathematical model. Radial expansion rates for both contrast-enhancing (p = 0.0040) and T2 hyperintense regions (p = 0.0016) were significantly higher in WHO II-IV tumors compared with nontransformers. Similarly, model estimates showed a significantly higher proliferation (p = 0.0324) and invasion rate (p = 0.0050) in WHO II-IV tumors compared with nontransformers. Tumor growth kinetics can identify contrast-enhancing diffuse astrocytomas undergoing malignant transformation.

Inhibition of intracerebral glioblastoma growth by targeting the insulin-like growth factor 1 receptor involves different context-dependent mechanisms.

Signaling by insulin-like growth factor 1 receptor (IGF-1R) can contribute to the formation and progression of many diverse tumor types, including glioblastoma. We investigated the effect of the IGF-1R blocking antibody IMC-A12 on glioblastoma growth in different in vivo models. U87 cells were chosen to establish rapidly growing, angiogenesis-dependent tumors in the brains of nude mice, and the GS-12 cell line was used to generate highly invasive tumors. IMC-A12 was administered using convection-enhanced local delivery. Tumor parameters were quantified histologically, and the functional relevance of IGF-1R activation was analyzed in vitro. IMC-A12 treatment inhibited the growth of U87 and GS-12 tumors by 75% and 50%, respectively. In GS-12 tumors, the invasive tumor extension and proliferation rate were significantly reduced by IMC-A12 treatment, while apoptosis was increased. In IMC-A12-treated U87 tumors, intratumoral vascularization was markedly decreased, and tumor cell proliferation was moderately reduced. Flow cytometry showed that <2% of U87 cells but >85% of GS-12 cells expressed IGF-1R. Activation of IGF-1R by IGF-1 and IGF-2 in GS-12 cells was blocked by IMC-A12. Both ligands stimulated GS-12 cell proliferation, and IGF-2 also stimulated migration. IMC-A12 inhibited these stimulatory effects and increased apoptosis. In U87 cells, stimulation with either ligand had no functional effect. IGF-1R blockade can inhibit glioblastoma growth by different mechanisms, including direct effects on the tumor cells as well as indirect anti-angiogenic effects. Hence, blocking IGF-1R may be useful to target both the highly proliferative, angiogenesis-dependent glioblastoma core component as well as the infiltrative periphery.

YAP immunoreactivity is directly related to pilomatrixoma size and proliferation rate.

Organ size regulation is a highly coordinated process involving complex mechanisms. Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif, also known as WWTR1 (TAZ) have recently been linked to organ size determination and cell proliferation. Pilomatrixoma (PM) is a benign tumor of the adnexal appendages with a certain degree of differentiation toward the matrix of the hair follicle. PM presents as a dermal nodule that usually ranges from 0.5 to 2 cm, rarely exceeding 3 cm. We recently observed a case of unusual "giant" (6.5 cm) PM. Our hypothesis was that YAP and TAZ could be related to PM growth. We analyzed YAP and TAZ immunohistochemical expression in the giant and in ten usual size PMs in relation with tumor size and proliferation rate. YAP nuclear expression was remarkably higher in the giant PM in comparison with usual size PMs and statistically correlated, in a direct manner, with size and proliferation rate of PMs. Contrariwise, TAZ nuclear expression seemed stochastic. Our findings suggest that YAP could play a role in PM growth.

P53 and cancer-associated sialylated glycans are surrogate markers of cancerization of the bladder associated with Schistosoma haematobium infection.

BackgroundBladder cancer is a significant health problem in rural areas of Africa and the Middle East where Schistosoma haematobium is prevalent, supporting an association between malignant transformation and infection by this blood fluke. Nevertheless, the molecular mechanisms linking these events are poorly understood. Bladder cancers in infected populations are generally diagnosed at a late stage since there is a lack of non-invasive diagnostic tools, hence enforcing the need for early carcinogenesis markers.Methodology/Principal FindingsForty-three formalin-fixed paraffin-embedded bladder biopsies of S. haematobium-infected patients, consisting of bladder tumours, tumour adjacent mucosa and pre-malignant/malignant urothelial lesions, were screened for bladder cancer biomarkers. These included the oncoprotein p53, the tumour proliferation rate (Ki-67>17%), cell-surface cancer-associated glycan sialyl-Tn (sTn) and sialyl-Lewisa/x (sLea/sLex), involved in immune escape and metastasis. Bladder tumours of non-S. haematobium etiology and normal urothelium were used as controls. S. haematobium-associated benign/pre-malignant lesions present alterations in p53 and sLex that were also found in bladder tumors. Similar results were observed in non-S. haematobium associated tumours, irrespectively of their histological nature, denoting some common molecular pathways. In addition, most benign/pre-malignant lesions also expressed sLea. However, proliferative phenotypes were more prevalent in lesions adjacent to bladder tumors while sLea was characteristic of sole benign/pre-malignant lesions, suggesting it may be a biomarker of early carcionogenesis associated with the parasite. A correlation was observed between the frequency of the biomarkers in the tumor and adjacent mucosa, with the exception of Ki-67. Most S. haematobium eggs embedded in the urothelium were also positive for sLea and sLex. Reinforcing the pathologic nature of the studied biomarkers, none was observed in the healthy urothelium.Conclusion/SignificanceThis preliminary study suggests that p53 and sialylated glycans are surrogate biomarkers of bladder cancerization associated with S. haematobium, highlighting a missing link between infection and cancer development. Eggs of S. haematobium express sLea and sLex antigens in mimicry of human leukocytes glycosylation, which may play a role in the colonization and disease dissemination. These observations may help the early identification of infected patients at a higher risk of developing bladder cancer and guide the future development of non-invasive diagnostic tests.

PM-04 * IN SILICO ANALYSIS OF AVAglio AND RTOG 0825 PHASE III CLINICAL TRIALS SUGGESTS SIGNATURES OF PATIENTS TO RECEIVE BENEFIT FROM COMBINED BEVACIZUMAB AND RADIATION THERAPIES

Despite the growing interest in anti-angiogenic therapies for glioblastoma (GBM), no statistically significant evidence has been found to indicate that bevacizumab in combination with other therapies increases the overall survival of glioblastoma patients. Most recently two phase III trials, AVAglio and RTOG 0825, were concluded considering bevacizumab in the upfront setting in combination with radiation and chemotherapy. Although the aggregate results of these Phase III studies were disappointing, there remains an open question of the potential benefits of this combination therapy for predictable subpopulations of patients. We utilize a mathematical model of GBM growth which incorporates vascular density, hypoxia and necrosis to investigate differential benefits of combination therapy consisting of surgical resection, radiation and bevacizumab. Proliferation and migration rates of the simulated tumors were varied across known growth dynamics observed in human GBMs. The model assumes that the anti-angiogenic therapy normalizes vasculature and thus decreases hypoxia. We assess the differential hypoxic burden left after a gross total resection along with the change in radiation cell kill from re-normalization of the tissue due to treatment with bevacizumab. We found that hypoxic burden and the resulting change in radiation induced cell kill varied dramatically across a range of tumor growth kinetics. Under the assumption of vasculature renormalization leading to decreased hypoxia, we determined that patients undergoing a gross total resection, which is the case for about 50% of the patients enrolled in the AVAglio and RTOG 0825 Phase III trials, would not likely benefit from combination therapy because the majority of the hypoxic burden would have been surgically removed. For patients not undergoing a gross total resection, our results indicate that there is a sub-population of patients, those with large tumors and high proliferation rates, who would have a dramatic change in the total radiation cell kill when combined with anti-angiogenic therapy.

SEOM clinical guidelines for the diagnosis and treatment of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) 2014.

GEP-NENs are a challenging family of tumors of growing incidence and varied clinical management and behavior. Diagnostic techniques have substantially improved over the past decades and significant advances have been achieved in the understanding of the molecular pathways governing tumor initiation and progression. This has already translated into relevant advances in the clinic. This guideline aims to provide practical recommendations for the diagnosis and treatment of GEP-NENs. Diagnostic workup, histological and staging classifications, and the different available therapeutic approaches, including surgery, liver-directed ablative therapies, peptide receptor radionuclide therapy, and systemic hormonal, cytotoxic or targeted therapy, are briefly discussed in this manuscript. Clinical presentation (performance status, comorbidities, tumor-derived symptoms and hormone syndrome in functioning tumors), histological features [tumor differentiation, proliferation rate (Ki-67), and expression of somatostatin receptors], disease localization and extent, and resectability of primary and metastatic disease, are all key issues that shall be taken into consideration to appropriately tailor therapeutic strategies and surveillance of these patients.

Adipose stem cell therapy in cancer reconstruction: a critical review.

Found in most mesenchymally derived organs, mesenchymal stem cells are undifferentiated cells capable of developing into many cell types. Adipose stem cells are a type of mesenchymal stem cell easily extracted from lipoaspirate, often readily available, and are conformable to the tissue defect. Their ability for self-renewal, unlimited proliferation and proangiogenic, and immunomodulatory properties have made them attractive adjuncts in plastic surgery. Since the discovery of pluripotent cells in adipose tissue, plastic surgeons have applied the technology toward improving wound healing, soft tissue augmentation, and tissue engineering. More recently, some surgeons have used adipose stem cells in cancer reconstruction. By mixing lipoaspirate with concentrated fractions of adipose stem cells through a technique termed cell-assisted lipotransfer, plastic surgeons have claimed improved aesthetic results. Promising early results have been tempered by in vitro and animal studies demonstrating increased tumor proliferation and metastasis rates with the use of adipose and other mesenchymal stem cells. This review provides a succinct yet comprehensive overview of the current literature evaluating the oncologic risks associated with adipose stem cell use in cancer.