Metabolic Switch and Cytotoxic Effect of Metformin on Burkitt Lymphoma.

Altered cellular energetic metabolism has recently emerged as important feature of neoplastic cells. Indeed, interfering with cancer cell metabolism might represent a suitable therapeutic strategy. In this study, we aimed to assess glucose metabolism activation in human lymphomas and evaluate how metformin can exert its action on lymphoma cells. We studied a large series of human lymphomas (N = 252) and an in vitro model of Burkitt lymphoma (BL) cells. We combined molecular biology techniques, including global gene expression profiling (GEP) analysis, quantitative PCR (qPCR) and Western blotting, and biochemical assays, aimed to assess pentose phosphate pathway, tricarboxylic acid (TCA) cycle, and aerobic glycolysis rates. We found that glucose metabolism is overall enhanced in most lymphoma subtypes, based on gene expression profiling (GEP), with general shift to aerobic glycolysis. By contrast, normal B cells only showed an overall increase in glucose usage during germinal center transition. Interestingly, not only highly proliferating aggressive lymphomas but also indolent ones, like marginal zone lymphomas, showed the phenomenon. Consistently, genes involved in glycolysis were confirmed to be overexpressed in BL cells by qPCR. Biochemical assays showed that while aerobic glycolysis is increased, TCA cycle is reduced. Finally, we showed that metformin can induce cell death in BL cells by stressing cellular metabolism through the induction of GLUT1, PKM2, and LDHA. In conclusion, we unveiled glucose metabolism abnormalities in human lymphomas and characterized the mechanism of action of metformin in Burkitt lymphoma model.

Clinical Relevance of ABCB1, ABCG2, and ABCC2 Gene Polymorphisms in Chronic Myeloid Leukemia Patients Treated With Nilotinib.

Tyrosine kinase inhibitors (TKIs) have radically changed the outcome of chronic myeloid leukemia (CML) patients in the last 20 years. Moreover, the advent of second generation TKIs, namely nilotinib and dasatinib, have largely increased the number of CML patients achieving deep and sustained molecular responses. However, the possible mechanisms capable of influencing the maintenance of the long-term molecular response are not yet fully known and understood. In this light, polymorphisms in MDR-ABC transporters may influence the efficacy and safety of TKIs. In this study, we examined seven single nucleotide polymorphisms (SNPs) in four ABC transporter genes: ABCC1 rs212090 (5463T>A), ABCC2 rs3740066 (3972C>T), ABCC2 rs4148386 G>A, ABCC2 rs1885301 (1549G>A), ABCG2 rs2231137 (34G>A), ABCG2 rs2231142 G>C, ABCB1 rs1045642 (3435C>T), to determine their effect on the achievement and/or loss of molecular response in 90 CML patients treated with nilotinib. We found that ABCC2 rs3740066 CC and CT as well as the ABCB1 rs1045642 TT genotypes correlated with a higher probability to achieve MR3 in a shorter time (p=0.02, p=0.004, and p=0.01), whereas ABCG2 rs2231137 GG was associated with lower probability of MR3 achievement (p=0.005). Moreover, ABCC2 rs3740066 CC genotype, the ABCB1 rs1045642 CC and TT genotypes were positively correlated with MR4 achievement (p=0.02, p=0.007, and p=0.003). We then generated a predictive model incorporating the information of four genotypes, to evaluate the combined effect of the SNPs. The combination of SNPs present in the model affected the probability and the time to molecular response. This model had a high prognostic significance for both MR3 and MR4 (p=0.005 and p=0.008, respectively). Finally, we found ABCG2 rs2231142 GG genotype to be associated with a decrease risk of MR3 loss. In conclusion, MDR-transporters SNPs may significantly affect the achievement and loss of molecular response in CML patients treated with nilotinib.

TP53 Mutation Analysis in Gastric Cancer and Clinical Outcomes of Patients with Metastatic Disease Treated with Ramucirumab/Paclitaxel or Standard Chemotherapy.

Loss of p53 promotes vascular endothelial growth factor (VEGF)-A up-regulation and the angiogenic potential of cancer cells. We investigated TP53 somatic mutations in 110 primary gastric adenocarcinomas of two retrospective metastatic series including 48 patients treated with second-line Ramucirumab/Paclitaxel and 62 patients who received first-line chemotherapy with Cisplatin or Oxaliplatin plus 5-Fluorouracil. Missense mutations were classified by tumor protein p53 (TP53) mutant-specific residual transcriptional activity scores (TP53RTAS) and used to stratify patients into two groups: transcriptionally TP53Active and TP53Inactive. The primary endpoint was overall survival (OS). An additional analysis was addressed to measure VEGF/VEGF receptor 2 (VEGFR2) expression levels in relation to the TP53RTAS. In the Ramucirumab/Paclitaxel group, 29/48 (60.4%) patients had TP53 mutations. Ten patients with TP53Inactive mutations showed better OS than carriers of other TP53 mutations. This effect was retained in the multivariate model analysis (Hazard Ratio = 0.29, 95% confidence interval = 0.17-0.85, p = 0.02). In the chemotherapy group, 41/62 (66%) patients had TP53 mutations, and the 11 carriers of TP53Inactive mutations showed the worst OS (Hazard Ratio = 2.64, 95% confidence interval = 1.17-5.95, p = 0.02). VEGF-A mRNA expression levels were significantly increased in TP53Inactive cases. Further studies are warranted to explore the effect of TP53Inactive mutations in different anti-cancer regimens. This information would lead to new tailored therapy strategies for this lethal disease.

Glycolytic competence in gastric adenocarcinomas negatively impacts survival outcomes of patients treated with salvage paclitaxel-ramucirumab.

INTRODUCTION: For energy production, cancer cells maintain a high rate of glycolysis instead of oxidative phosphorylation converting glucose into lactic acid. This metabolic shift is useful to survive in unfavorable microenvironments. We investigated whether a positive glycolytic profile (PGP) in gastric adenocarcinomas may be associated with unfavorable outcomes under an anticancer systemic therapy, including the anti-angiogenic ramucirumab. MATERIALS AND METHODS: Normal mucosa (NM) and primary tumor (PT) of 40 metastatic gastric adenocarcinomas patients who received second-line paclitaxel-ramucirumab (PR) were analyzed for mRNA expression of the following genes: HK-1, HK-2, PKM-2, LDH-A, and GLUT-1. Patients were categorized with PGP when at least a doubling of mRNA expression (PT vs. NM) in all glycolytic core enzymes (HK-1 or HK-2, PKM-2, LDH-A) was observed. PGP was also related to TP53 mutational status. RESULTS: Mean LDH-A, HK-2, PKM-2 mRNA expression levels were significantly higher in PT compared with NM. 18 patients were classified as PGP, which was associated with significantly worse progression-free and overall survival times. No significant association was observed between PGP and clinical-pathologic features, including TP53 positive mutational status, in 28 samples. CONCLUSIONS: Glycolytic proficiency may negatively affect survival outcomes of metastatic gastric cancer patients treated with PR systemic therapy. TP53 mutational status alone does not seem to explain such a metabolic shift.

Author Correction: Sex-Related Differences in Impact on Safety of Pharmacogenetic Profile for Colon Cancer Patients Treated with FOLFOX-4 or XELOX Adjuvant Chemotherapy.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Sex-Related Differences in Impact on Safety of Pharmacogenetic Profile for Colon Cancer Patients Treated with FOLFOX-4 or XELOX Adjuvant Chemotherapy.

Polymorphisms contribute to inter-individual differences and show a promising predictive role for chemotherapy-related toxicity in colon cancer (CC). TOSCA is a multicentre, randomized, non-inferiority, phase III study conducted in high-risk stage II/stage III CC patients treated with 6 vs 3 months of FOLFOX-4 or XELOX adjuvant chemotherapy. During this post-hoc analysis, 218 women and 294 men were genotyped for 17 polymorphisms: TYMS (rs34743033, rs2853542, rs11280056), MTHFR (rs1801133, rs1801131), ERCC1 (rs11615), XRCC1 (rs25487), XRCC3 (rs861539), XPD (rs1799793, rs13181), GSTP1 (rs1695), GSTT1/GSTM1 (deletion +/-), ABCC1 (rs2074087), and ABCC2 (rs3740066, rs1885301, rs4148386). The aim was to assess the interaction between these polymorphisms and sex, on safety in terms of time to grade ≥3 haematological (TTH), grade ≥3 gastrointestinal (TTG) and grade ≥2 neurological (TTN) toxicity. Interactions were detected on TTH for rs1801133 and rs1799793, on TTG for rs13181 and on TTN for rs11615. Rs1799793 GA genotype (p = 0.006) and A allele (p = 0.009) shortened TTH in men. In women, the rs11615 CC genotype worsened TTN (co-dominant model p = 0.008, recessive model p = 0.003) and rs13181 G allele improved the TTG (p = 0.039). Differences between the two sexes in genotype distribution of rs1885301 (p = 0.020) and rs4148386 (p = 0.005) were found. We highlight that polymorphisms could be sex-specific biomarkers. These results, however, need to be confirmed in additional series.

DNA demethylating antineoplastic strategies: a comparative point of view.

Despite the involvement of genetic alterations in neoplastic cell transformation, it is increasingly evident that abnormal epigenetic patterns, such as those affecting DNA methylation and histone posttranslational modifications (PTMs), play an essential role in the early stages of tumor development. This finding, together with the evidence that epigenetic changes are reversible, enabled the development of new antineoplastic therapeutic approaches known as epigenetic therapies. Epigenetic modifications are involved in the control of gene expression, and their aberrant distribution is thought to participate in neoplastic transformation by causing the deregulation of crucial cellular pathways. Epigenetic drugs are able to revert the defective gene expression profile of cancer cells and, consequently, reestablish normal molecular pathways. Considering the emerging interest in epigenetic therapeutics, this review focuses on the approaches affecting DNA methylation, evaluates novel strategies and those already approved for clinical use, and compares their therapeutic potential.