Selective DNA-PK Inhibition Enhances Chemotherapy and Ionizing Radiation Activity in Soft-Tissue Sarcomas.

PURPOSE: Patients with advanced soft-tissue sarcomas (STS) exhibit a poor prognosis and have few therapeutic options. DNA-dependent protein kinase (DNA-PK) catalytic subunit is a multifunctional serine-threonine protein kinase that plays a crucial role in DNA double-strand damage repair via nonhomologous end joining. EXPERIMENTAL DESIGN: To investigate the therapeutic potential of DNA-PK targeting in STS, we first evaluated the prognostic value of DNA-PK expression in two large cohorts of patients with STS. We then used the potent and selective DNA-PK inhibitor AZD7648 compound to investigate the antitumor effect of the pharmacologic inhibition of DNA-PK in vitro via MTT, apoptosis, cell cycle, and proliferation assays. In vivo studies were performed with patient-derived xenograft models to evaluate the effects of AZD7648 in combination with chemotherapy or ionizing radiation on tumor growth. The mechanisms of sensitivity and resistance to DNA-PK inhibition were investigated by using a genome-wide CRISPR-Cas9 positive screen. RESULTS: DNA-PK overexpression is significantly associated with poor prognosis in patients with sarcomas. Selective pharmacologic inhibition of DNA-PK strongly synergizes with radiation- and doxorubicin-based regimen in sarcoma models. By using a genome-wide CRISPR-Cas9 positive screen, we identified genes involved in sensitivity to DNA-PK inhibition. CONCLUSIONS: DNA-PK inhibition deserves clinical investigation to improve response to current therapies in patients with sarcoma.

High throughput profiling of undifferentiated pleomorphic sarcomas identifies two main subgroups with distinct immune profile, clinical outcome and sensitivity to targeted therapies.

BACKGROUND: Undifferentiated pleomorphic sarcoma (UPS) is the most frequent, aggressive and less-characterized sarcoma subtype. This study aims to assess UPS molecular characteristics and identify specific therapeutic targets. METHODS: High-throughput technologies encompassing immunohistochemistry, RNA-sequencing, whole exome-sequencing, mass spectrometry, as well as radiomics were used to characterize three independent cohorts of 110, 25 and 41 UPS selected after histological review performed by an expert pathologist. Correlations were made with clinical outcome. Cell lines and xenografts were derived from human samples for functional experiments. FINDINGS: CD8 positive cell density was independently associated with metastatic behavior and prognosis. RNA-sequencing identified two main groups: the group A, enriched in genes involved in development and stemness, including FGFR2, and the group B, strongly enriched in genes involved in immunity. Immune infiltrate patterns on tumor samples were highly predictive of gene expression classification, leading to call the group B 'immune-high' and the group A 'immune-low'. This molecular classification and its prognostic impact were confirmed on an independent cohort of UPS from TCGA. Copy numbers alterations were significantly more frequent in immune-low UPS. Proteomic analysis identified two main proteomic groups that highly correlated with the two main transcriptomic groups. A set of nine radiomic features from conventional MRI sequences provided the basis for a radiomics signature that could select immune-high UPS on their pre-therapeutic imaging. Finally, in vitro and in vivo anti-tumor activity of FGFR inhibitor JNJ-42756493 was selectively shown in cell lines and patient-derived xenograft models derived from immune-low UPS. INTERPRETATION: Two main disease entities of UPS, with distinct immune phenotypes, prognosis, molecular features and MRI textures, as well as differential sensitivity to specific anticancer agents were identified. Immune-high UPS may be the best candidates for immune checkpoint inhibitors, whereas this study provides rational for assessing FGFR inhibition in immune-low UPS. FUNDING: This work was partly founded by a grant from La Ligue.

Novel Therapeutic Insights in Dedifferentiated Liposarcoma: A Role for FGFR and MDM2 Dual Targeting.

We aimed to evaluate the therapeutic potential of the pan-FGFR inhibitor erdafitinib to treat dedifferentiated liposarcoma (DDLPS). FGFR expression and their prognostic value were assessed in a series of 694 samples of well-differentiated/dedifferentiated liposarcoma (WDLPS/DDLPS). The effect of erdafitinib-alone or in combination with other antagonists-on tumorigenicity was evaluated in vitro and in vivo. We detected overexpression of FGFR1 and/or FGFR4 in a subset of WDLPS and DDLPS and demonstrated correlation of this expression with poor prognosis. Erdafitinib treatment reduced cell viability, inducing apoptosis and strong inhibition of the ERK1/2 pathway. Combining erdafitinib with the MDM2 antagonist RG7388 exerted a synergistic effect on viability, apoptosis, and clonogenicity in one WDLPS and two DDLPS cell lines. Efficacy of this combination was confirmed in vivo on a DDLPS xenograft. Importantly, we report the efficacy of erdafitinib in one patient with refractory DDLPS showing disease stabilization for 12 weeks. We provide evidence that the FGFR pathway has therapeutic potential for a subset of DDLPS and that an FGFR1/FGFR4 expression might constitute a powerful biomarker to select patients for FGFR inhibitor clinical trials. In addition, we show that combining erdafitinib with RG7388 is a promising strategy for patients with DDLPS that deserves further investigation in the clinical setting.

MDM2 Antagonists Induce a Paradoxical Activation of Erk1/2 through a P53-Dependent Mechanism in Dedifferentiated Liposarcomas: Implications for Combinatorial Strategies.

The MDM2 gene is amplified in dedifferentiated liposarcoma (DDLPS). Treatment with MDM2 antagonists is a promising strategy to treat DDLPS; however, drug resistance is a major limitation when these drugs are used as a single agent. This study examined the impact of MDM2 antagonists on the mitogen-activated protein kinase (MAPK) pathway in DDLPS and investigated the potential synergistic activity of a MAPK kinase (MEK) inhibitor in combination with MDM2 antagonists. We identified a synergistic effect and identified the mechanism behind it. Combination effects of MDM2 antagonists and a MEK inhibitor were analyzed in a patient-derived xenograft mouse model and in DDLPS and leiomyosarcoma cell lines using different cell proliferation assays and immunoblot analysis. MDM2 antagonist (RG7388)-resistant IB115 [P4] cells and p53-silenced DDLPS cells were also established to understand the importance of functional p53. We found that MDM2 antagonists induced an upregulation of phosphorylated extracellular signal-regulated kinase (p-ERK) in DDLPS cells. The upregulation of p-ERK occurred due to mitochondrial translocation of p53, which resulted in increased production of reactive oxygen species, causing the activation of receptor tyrosine kinases (RTKs). Activated RTKs led to the activation of the downstream MEK/ERK signaling pathway. Treatment with a MEK inhibitor resulted in decreased expression of p-ERK, causing significant anti-tumor synergy when combined with MDM2 antagonists. Our results provide a framework for designing clinical studies of combination therapies in DDLPS patients.

ATR Inhibition Broadly Sensitizes Soft-Tissue Sarcoma Cells to Chemotherapy Independent of Alternative Lengthening Telomere (ALT) Status.

Only few drugs have shown activity in patients with advanced soft-tissue and the median overall survival is only 18 months. Alterations of genes involved in the DNA damage repair pathway have been associated with sarcoma risk and prognosis. ATR plays a crucial role in maintaining genomic integrity by responding to a large spectrum of DNA damage, including double strand breaks (DSBs) that interfere with replication. The objective of this study is to evaluate the pre-clinical activity of ATR inhibition in soft tissue sarcomas (STS). We explored the ability of the ATR inhibitor, VE-822, to prevent chemotherapy-induced intra-S-phase checkpoint activation and evaluated the antitumor potential of this combination in vitro and in vivo in STS cell lines and in a patient-derived xenograft model. The combination of VE-822 and gemcitabine in vitro was synergistic, inhibited cell proliferation, induced apoptosis, and accumulated in the S phase of the cell cycle with higher efficacy than either single agent alone. The combination also resulted in enhanced γH2AX intranuclear accumulation as a result of DNA damage induction. These effects were unrelated to the alternative lengthening of telomeres pathway. In vivo, the combination of VE-822 and gemcitabine significantly enhanced tumor growth inhibition and progression-free survival in an aggressive model of undifferentiated pleomorphic sarcoma. The combination of ATR inhibitor and chemotherapy is beneficial in pre-clinical models of soft-tissue sarcoma and deserves further exploration in the clinical setting.

LRRC15 Targeting in Soft-Tissue Sarcomas: Biological and Clinical Implications.

BACKGROUND: LRRC15 is a member of the LRR (leucine-rich repeat) superfamily present on tumor-associated fibroblasts (CAFs) and stromal cells. The expression of LRRC15 is upregulated by the pro-inflammatory cytokine TGFß. ABBV-085 is a monomethyl auristatin E (MMAE)-containing antibody-drug conjugate (ADC) designed to target LRRC15, and which has shown significant anti-tumor activity in several tumor models. This is the first focused examination of LRRC15 expression and ABBV-085 activity in soft-tissue sarcomas (STS). METHODS: We analyzed the LRRC15 expression profile by immunohistochemistry in 711 STS cases, covering a broad spectrum of STS histologies and sub-classifications. In vivo experiments were carried out by using LRRC15-positive and LRRC15-negative patient-derived xenograft (PDX) models of STS. RESULTS: In contrast to patterns observed in epithelial tumors, LRRC15 was expressed not only by stromal cells but also by cancer cells in multiple subsets of STS with significant variations noted between histological subtypes. Overexpression of LRRC15 is positively correlated with grade and independently associated with adverse outcome. ABBV-085 has robust preclinical efficacy against LRRC15 positive STS patient-derived xenograft (PDX) models. CONCLUSION: We provide the first preclinical evidence that LRRC15 targeting with an antibody-drug conjugate is a promising strategy in LRRC15-positive STS. ABBV-085 is being evaluated in an ongoing clinical trial in STS and other malignancies.

Expression of Concern to: Identifying and targeting cancer stem cells in leiomyosarcoma: prognostic impact and role to overcome secondary resistance to PI3K/mTOR inhibition.

The Editor-in-Chief would like to alert readers that the ownership of some of the data presented in this article [1].

Identifying and targeting cancer stem cells in leiomyosarcoma: prognostic impact and role to overcome secondary resistance to PI3K/mTOR inhibition.

BACKGROUND: Leiomyosarcoma (LMS) is one of the most frequent soft tissue sarcoma subtypes and is characterized by a consistent deregulation of the PI3K/mTOR pathway. Cancer stem cells (CSCs) have been poorly studied in soft tissue sarcomas. In this study, we aimed to evaluate the association between CSCs, the outcome of LMS patients, and the resistance to PI3K/mTOR pathway inhibition. METHODS: We investigated the relationships between aldehyde dehydrogenase 1 (ALDH1) expression, a cancer stem cell marker, and the outcome of LMS patients in two independent cohorts. We assessed the impact of CSCs in resistance to PI3K/mTOR pathway inhibition using LMS cell lines, a xenograft mouse model, and human tumor samples. RESULTS: We found that enhanced ALDH1 activity is a hallmark of LMS stem cells and is an independent prognostic factor. We also identified that secondary resistance to PI3K/mTOR pathway inhibition was associated with the expansion of LMS CSCs. Interestingly, we found that EZH2 inhibition, a catalytic component of polycomb repressive complex which plays a critical role in stem cell maintenance, restored sensitivity to PI3K/mTOR pathway inhibition. Importantly, we confirmed the clinical relevance of our findings by analyzing tumor samples from patients who showed secondary resistance after treatment with a PI3Kα inhibitor. CONCLUSIONS: Altogether, our findings suggest that CSCs have a strong impact on the outcome of patients with LMS and that combining PI3K/mTOR and EZH2 inhibitors may represent a promising strategy in this setting.

Combined targeting of MDM2 and CDK4 is synergistic in dedifferentiated liposarcomas.

PURPOSE: MDM2 and CDK4 are frequently co-amplified in well-differentiated/dedifferentiated liposarcoma (WDLPS/DDLPS). We aimed to determine whether combined MDM2/CDK4 targeting is associated with higher antitumour activity than a single agent in preclinical models of DDLPS. EXPERIMENTAL DESIGN: DDLPS cells were exposed to RG7388 (MDM2 antagonist) and palbociclib (CDK4 inhibitor), and apoptosis and signalling/survival pathway perturbations were monitored by flow cytometry and Western blotting. Xenograft mouse models were used to assess tumour growth and survival. Treatment efficacy was assessed by Western blotting, histopathology and tumour volume. RESULTS: RG7388 and palbociclib together exerted a greater antitumour effect than either drug alone, with significant differences in cell viability after a 72-h treatment with RG7388 and/or palbociclib. The combination treatment significantly increased apoptosis compared to the single agents. We then analysed the in vivo antitumour activity of RG7388 and palbociclib in a xenograft model of DDLPS. The combination regimen reduced the tumour growth rate compared with a single agent alone and significantly increased the median progression-free survival. CONCLUSIONS: Our results provide a strong rationale for evaluating the therapeutic potential of CDK4 inhibitors as potentiators of MDM2 antagonists in DDLPS and justify clinical trials in this setting.

Dual inhibition of the PI3K/AKT/mTOR pathway suppresses the growth of leiomyosarcomas but leads to ERK activation through mTORC2: biological and clinical implications.

The PI3K/AKT/mTOR pathway plays a crucial role in the development of leiomyosarcomas (LMSs). In this study, we tested the efficacy of dual PI3K/mTOR (BEZ235), PI3K (BKM120) and mTOR (everolimus) inhibitors in three human LMS cell lines. In vitro and in vivo studies using LMS cell lines showed that BEZ235 has a significantly higher anti-tumor effect than either BKM120 or everolimus, resulting in a greater reduction in tumor growth and more pronounced inhibitory effects on mitotic activity and PI3K/AKT/mTOR signaling. Strikingly, BEZ235 but neither BKM120 nor everolimus markedly enhanced the ERK pathway. This effect was reproduced by the combination of BKM120 and everolimus, suggesting the involvement of mTORC2 via a PI3K-independent mechanism. Silencing of RICTOR in LMS cells confirmed the role of mTORC2 in the regulation of ERK activity. Combined treatment with BEZ235 and GSK1120212, a potent MEK inhibitor, resulted in synergistic growth inhibition and apoptosis induction in vitro and in vivo. These findings document for the first time that dual PI3K/mTOR inhibition in leiomyosarcomas suppress a negative feedback loop mediated by mTORC2, leading to enhanced ERK pathway activity. Thus, combining a dual PI3K/mTOR inhibitor with MEK inhibitors may be a relevant approach to increase anti-tumor activity and prevent drug resistance in patients with LMS.

Efficacy of doxorubicin-transferrin conjugate in apoptosis induction in human leukemia cells through reactive oxygen species generation.

BACKGROUND: Doxorubicin (DOX) is a small molecular cytotoxic agent that can be transferred efficiently to cancer cells by nanocarriers. This anthracycline antibiotic serves as an effective anti-neoplastic drug against both hematological and solid malignancies. Here, we set out to assess the capacity of a novel doxorubicin - transferrin conjugate (DOX-TRF) to provoke apoptosis in human normal and leukemia cells through free radicals produced via a redox cycle of doxorubicin (DOX) when released from its conjugate. METHODS: After DOX-TRF exposure, we determined the time-course of apoptotic and necrotic events, the generation of reactive oxygen species (ROS), changes in mitochondrial membrane potential, as well as alterations in cytochrome c levels and intracellular calcium concentrations in human leukemia-derived cell lines (CCRF-CEM, K562 and its doxorubicin-resistant derivative K562/DOX) and normal peripheral blood-derived mononuclear cells (PBMC). RESULTS: We found that DOX-TRF can induce apoptosis in all leukemia-derived cell lines tested, which was associated with morphological changes and decreases in mitochondrial membrane potential. In comparison to free DOX treated cells, we observed a time-dependency between a higher level of ROS generation and a higher drop in mitochondrial membrane potential, particularly in the doxorubicin-resistant cell line. In addition, we found that the apoptotic cell death induced by DOX-TRF was directly associated with a release of cytochrome c from the mitochondria and an increase in intracellular calcium level in all human leukemia-derived cell lines tested. CONCLUSIONS: Our data indicate that DOX-TRF is considerably more cytotoxic to human leukemia cells than free DOX. In addition, we show that DOX-TRF can effectively produce free radicals, which are directly involved in apoptosis induction.

PRIMA-1(MET) induces death in soft-tissue sarcomas cell independent of p53.

BACKGROUND: The aim of this study was to explore the efficacy and define mechanisms of action of PRIMA-1(MET) as a TP53 targeted therapy in soft-tissue sarcoma (STS) cells. METHODS: We investigated effects of PRIMA-1(MET) on apoptosis, cell cycle, and induction of oxidative stress and autophagy in a panel of 6 STS cell lines with different TP53 status. RESULTS: Cell viability reduction by PRIMA-1(MET) was significantly observed in 5 out of 6 STS cell lines. We found that PRIMA-1(MET) was capable to induce cell death not only in STS cells harboring mutated TP53 but also in TP53-null STS cells demonstrating that PRIMA-1(MET) can induce cell death independently of TP53 in STS cells. We identified an important role of reactive oxygen species (ROS), involved in PRIMA-1(MET) toxicity in STS cells leading to a caspase-independent cell death. ROS toxicity was associated with autophagy induction or JNK pathway activation which represented potential mechanisms of cell death induced by PRIMA-1(MET) in STS. CONCLUSIONS: PRIMA-1(MET) anti-tumor activity in STS partly results from off-target effects involving ROS toxicity and do not deserve further development as a TP53-targeted therapy in this setting.

A phase II trial evaluating the efficacy and safety of efavirenz in metastatic castration-resistant prostate cancer.

BACKGROUND: Preclinical studies demonstrated that non-nucleoside reverse transcriptase inhibitors used for the treatment of HIV could antagonize tumor development. This led us to assess the efficacy of efavirenz in patients with metastatic castration-resistant prostate cancer (mCRPC) in a multicenter phase II study. METHODS: We used a Simon two-stage design and a 3-month prostate-specific antigen (PSA) nonprogression rate of 40% as a primary objective. Patients received 600 mg efavirenz daily with the possibility of a dose increase in case of PSA progression. Exploratory analyses included pharmacokinetics of efavirenz plasma concentrations and correlations with clinical outcomes. RESULTS: Among 53 assessable patients, we observed 15 instances of PSA nonprogression at 3 months, corresponding to a nonprogression rate of 28.3% (95% confidence interval: 16.8%-42.3%). The exploratory analysis revealed that for the 7 patients in whom optimal plasma concentration of efavirenz was achieved, PSA progression was observed in only 28.6% compared with 81.8% of patients with suboptimal plasma concentrations of efavirenz. CONCLUSION: Although 600 mg efavirenz did not statistically improve the PSA nonprogression rate, our exploratory analysis suggests that higher plasma concentrations of this drug (i.e., use of increased dosages) may be of potential benefit for the treatment of mCRPC.

Induction of apoptosis by doxorubicin-transferrin conjugate compared to free doxorubicin in the human leukemia cell lines.

In our research we compared the effect of doxorubicin (DOX) and doxorubicin-transferrin (DOX-TRF) conjugate on the induction of programmed cell death. All experiments were carried out on human leukemia cells: CCRF-CEM, K562 sensitive and resistant to DOX, (K562/DOX), which are the molecular model for the chronic and acute form of hematological malignancies, respectively. At the same time, studies were also performed on normal, peripheral blood mononuclear cells (PBMCs). The first stages of apoptosis, connected with externalization of phosphatidylserine (PS), were evaluated after comparing the viability of tested cell lines treated with DOX-TRF conjugate or free DOX. Morphological changes of nuclei connected with apoptosis were analyzed by double staining Hoechst 33258/propidium iodide. Subsequently, we conducted a more accurate evaluation of DOX-TRF-trigged cell death by using DNA ladder assay, measuring the activation of caspase-3, -8 and -9 and changes in poly-ADP ribose polymerase (PARP) activity. The percentage of apoptotic cells reached its maximum at 24 and 48 h incubation. Prolonged treatment time with DOX-TRF conjugate progressively increased the level of necrotic cells. At 24-48 h time points, we observed a significant increase in the activity of apoptosis-characterized enzymes (caspases -8, -9, -3). This study provided the evidence that DOX-TRF conjugate triggers apoptotic pathway connected with DNA damage mediated by the activation of pro-caspases and PARP cleavage.

Identification of methylguanine methyltransferase polymorphisms as genetic markers of individual susceptibility to therapy-related myeloid neoplasms.

PURPOSE: Myelodysplastic syndromes (MDS) are pre-leukaemic haematopoietic stem cell disorders. Among them, 10-20% occur after chemotherapy and/or radiotherapy, and are called 'therapy-related MDS' (t-MDS). The aim of this study was to identify genetic markers in t-MDS. METHODS: A prospective cohort of 59 MDS patients (39 de novo MDS, 20 t-MDS) was studied. A total of 384 single nucleotide polymorphisms (SNP) selected among genes involved in DNA repair, drug metabolism and transport, signal transduction and oncogenesis, were genotyped using a custom-made SNP chip. RESULTS: Two non-synonymous SNPs present in the methylguanine methyltransferase (MGMT) gene, in complete linkage disequilibrium, were significantly associated with t-MDS: rs2308321 and rs2308327, with a raw p value of 7.4 × 10(-5) and a corrected p value after Benjamini-Hochberg correction of 0.014. Other associations tested between clinical and cytogenetic features and SNP chip gene variants gave corrected p values above 0.05. A validation cohort was separately constituted of 43 patients (24 de novo MDS, 19 t-MDS) and the two MGMT SNPs were genotyped; it confirmed a significant association between the variant allele of MGMT and t-MDS (p=0.038). CONCLUSION: We thus identified a putative marker of the risk to develop MDS after cancer treatment.

Transferrin as a drug carrier: Cytotoxicity, cellular uptake and transport kinetics of doxorubicin transferrin conjugate in the human leukemia cells.

Leukemias are one of most common malignancies worldwide. There is a substantial need for new chemotherapeutic drugs effective against this cancer. Doxorubicin (DOX), used for treatment of leukemias and solid tumors, is poorly efficacious when it is administered systemically at conventional doses. Therefore, several strategies have been developed to reduce the side effects of this anthracycline treatment. In this study we compared the effect of DOX and doxorubicin-transferrin conjugate (DOX-TRF) on human leukemia cell lines: chronic erythromyeloblastoid leukemia (K562), sensitive and resistant (K562/DOX) to doxorubicin, and acute lymphoblastic leukemia (CCRF-CEM). Experiments were also carried out on normal cells, peripheral blood mononuclear cells (PBMC). We analyzed the chemical structure of DOX-TRF conjugate by using mass spectroscopy. The in vitro growth-inhibition assay XTT, indicated that DOX-TRF is more cytotoxic for leukemia cells sensitive and resistant to doxorubicin and significantly less sensitive to normal cells compared to DOX alone. During the assessment of intracellular DOX-TRF accumulation it was confirmed that the tested malignant cells were able to retain the examined conjugate for longer periods of time than normal lymphocytes. Comparison of kinetic parameters showed that the rate of DOX-TRF efflux was also slower in the tested cells than free DOX. The results presented here should contribute to the understanding of the differences in antitumor activities of the DOX-TRF conjugate and free drug.

Short curcumin treatment modulates oxidative stress, arginase activity, aberrant crypt foci, and TGF-ß1 and HES-1 transcripts in 1,2-dimethylhydrazine-colon carcinogenesis in mice.

This study investigated the effect of short curcumin treatment, a natural antioxidant on 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) in mice. The incidence of aberrant crypt foci (ACF) was 100%, with 54 ± 6 per colon, 10 weeks after the first DMH injection and reached 67 ± 12 per colon after 12 weeks. A high level of undifferentiated goblet cells and a weak apoptotic activity were shown in dysplastic ACF. The morphological alterations of colonic mucosa were associated to severe oxidative stress ratio with 43% increase in malondialdehyde vs. 36% decrease in GSH. DMH also increased inducible nitric synthase (iNOS) mRNA transcripts (250%), nitrites level (240%) and arginase activity (296%), leading to nitrosative stress and cell proliferation. Curcumin treatment, starting at week 10 post-DMH injection for 14 days, reduced the number of ACF (40%), iNOS expression (25%) and arginase activity (73%), and improved redox status by approximately 46%, compared to DMH-treated mice. Moreover, curcumin induced apoptosis of dysplastic ACF cells without restoring goblet cells differentiation. Interestingly, curcumin induced a parallel increase in TGF-ß1 and HES-1 transcripts (42% and 26%, respectively). In conclusion, the protective effect of curcumin was driven by the reduction of arginase activity and nitrosative stress. The up regulation of TGF-ß1 and HES-1 expression by curcumin suggests for the first time, a potential interplay between these signalling pathways in the chemoprotective mechanism of curcumin.

Evaluation of antiproliferative and anti-inflammatory activities of methanol extract and its fractions from the Mediterranean sponge.

BACKGROUND: Without doubt, natural products have been, and still are, the cornerstone of the health care armamentarium. Of all natural sources, the marine environment is clearly the last great frontier for pharmaceutical and medical research. METHODS: This work progresses in the direction of identifying component(s) from the Mediterranean sponge, Spongia officinalis with pharmacological activities. In the present study we investigated the efficacy of methanol extract and its semi-purified fractions (F2, F3) from Spongia officinalis for their in vivo anti-inflammatory activity using the carrageenan-induced paw edema in rats and their in vitro antiproliferative effects by their potential cytotoxic activity using the MTT colorimetric method and clonogenic inhibition against three human cancer cell lines (A549, lung cell carcinoma, HCT15, colon cell carcinoma and MCF7, breast adenocarcinoma). RESULTS: The fractions F2 and F3 showed interesting anti-inflammatory and antiproliferative activities in a dose dependent manner. CONCLUSIONS: The present study indicates that the methanolic extrac and its fractions from Spongia officinalis are a significant source of compounds with the antiproliferative and anti-inflammatory activities, and this may be useful for developing potential chemopreventive substances.

Absence of transcriptomic signature of response to chemotherapy in metastatic colorectal carcinoma patients.

AIM: Tumor gene-expression profiling may define signatures capable of discriminating between responders and nonresponders to chemotherapy. PATIENTS & METHODS: Fifty seven metastatic colorectal cancer patients were prospectively included and 40 tumors were analyzed. Patients were treated in first line with 5-fluorouracil associated with irinotecan or oxaliplatin. Response was evaluated using WHO criteria every 2 months after chemotherapy. Gene-expression profiling was performed using Applied Biosystems microarrays (Human Genome Survey Microarray v2.0; Paris, France). Data were analyzed using Bioconductor packages. Differential-expression analysis was performed by fitting a linear model. Moderated t-statistics were computed and p-values were adjusted for false-discovery rate. Pearson correlations tests were evaluated between gene expression and progression-free and overall survival. RESULTS: Nonsupervised analysis did not show any clustering of expression levels according to treatment response. Supervised analysis compared expression levels between responders and nonresponders, within each treatment group and independently from treatment. No genes were identified as differentially expressed at a p-value of 10(-3) and false-discovery rate of 30%. No correlation between expression levels and survival data was found. CONCLUSION: These negative results show that the determinants of response to chemotherapy should be sought not only in the tumor characteristics, but also among the processes leading to drug availability to the tumor.