Lucia Lombardi

Adjuvant colon cancer chemotherapy: where we are and where we'll go.

Many patients with early-stage colon cancer are cured with surgery alone, even if the standard of care remains an uniform approach to adjuvant chemotherapy based primarily on tumour stage. Consequently, it is important to individualize decision-making in this subset of patients with the aim to identify potential prognostic and predictive markers in colon cancer. While 5-fluorouracil, leucovorin, and oxaliplatin are widely known as gold treatment in the post-operative of stage III, well-validated molecular markers might help define which patients with stage II disease are likely to benefit from adjuvant therapy as well. Herein we review the use of adjuvant chemotherapy in colon cancer and analyzed the date on the clinical development of molecular markers to individualize another therapeutic approach in colon cancer.

Chemokine receptor CXCR4: Role in gastrointestinal cancer

Chemokines (CK)s, small proinflammatory chemoattractant cytokines that bind to specific G-protein coupled seven-span transmembrane receptors, are major regulators of cell trafficking and adhesion. The CXCL12 [stromal cell-derived factor-1 (SDF-1)] binds primarily to CXC receptor 4 (CXCR4; CD184). The binding of CXCL12 to CXCR4 induces intracellular signaling through several divergent pathways initiating signals related to chemotaxis, cell survival and/or proliferation, increase in intracellular calcium, and gene transcription. CXCR4 is expressed on multiple cell types including lymphocytes, hematopoietic stem cells, endothelial and epithelial cells, and cancer cells. One of the most intriguing and perhaps important roles that CKs and the CK receptors have is in regulating metastasis. Here, CK receptors may potentially facilitate tumor dissemination at each of the key steps of metastasis, including adherence of tumor cells to endothelium, extravasation from blood vessels, metastatic colonization, angiogenesis, proliferation, and protection from the host response via activation of key survival pathways such as ERK/MAPK, PI-3K/Akt/mTOR, or Jak/STAT, etc. In addition, it is increasingly recognized that CKs play an important role in facilitating communication between cancer cells and non-neoplatic cells in the tumor microenvironment (TME), including endothelial cells and fibroblasts, promoting the infiltration, activation of neutrophils, and tumor-associated macrophages within the TME. In this review, we mainly focus on the roles of chemokines CXCL12 and its cognate receptors CXCR4 as they pertain to cancer progression. In particular, we summarizes our current understanding regarding the contribution of CXCR4 and SDF-1 to gastrointestinal tumor behavior and its role in local progression, dissemination, and immune evasion of tumor cells. Also, describes recent therapeutic approaches that target these receptors or their ligands.

SIRT1 and circadian gene expression in pancreatic ductal adenocarcinoma: Effect of starvation

Pancreatic cancer (PC), the fourth leading cause of cancer-related deaths, is characterized by high aggressiveness and resistance to chemotherapy. Pancreatic carcinogenesis is kept going by derangement of essential cell processes, such as proliferation, apoptosis, metabolism and autophagy, characterized by rhythmic variations with 24-h periodicity driven by the biological clock. We assessed the expression of the circadian genes ARNLT, ARNLT2, CLOCK, PER1, PER2, PER3, CRY1, CRY2 and the starvation-activated histone/protein deacetylase SIRT1 in 34 matched tumor and non-tumor tissue specimens of PC patients, and evaluated in PC derived cell lines if the modulation of SIRT1 expression through starvation could influence the temporal pattern of expression of the circadian genes. We found a significant down-regulation of ARNLT (p = 0.015), CRY1 (p = 0.013), CRY2 (p = 0.001), PER1 (p < 0.0001), PER2 (p < 0.001), PER3 (p = 0.001) and SIRT1 (p = 0.017) in PC specimens. PER3 and CRY2 expression levels were lower in patients with jaundice at diagnosis ( < 0.05). Having adjusted for age, adjuvant therapy and tumor stage, we evidenced that patients with higher PER2 and lower SIRT1 expression levels showed lower mortality (p = 0.028). Levels and temporal patterns of expression of many circadian genes and SIRT1 significantly changed upon serum starvation in vitro, with differences among four different PC cell lines examined (BXPC3, CFPAC, MIA-PaCa-2 and PANC-1). Serum deprivation induced changes of the overall mean level of the wave and amplitude, lengthened or shortened the cycle time and phase-advanced or phase-delayed the rhythmic oscillation depending on the gene and the PC cell line examined. In conclusion, a severe deregulation of expression of SIRT1 and circadian genes was evidenced in the cancer specimens of PC patients, and starvation influenced gene expression in PC cell lines, suggesting that the altered interplay between SIRT1 and the core circadian proteins could represent a crucial player in the process of pancreatic carcinogenesis.

Adjuvant therapy in colon cancer

Colon cancer is the second leading cause of cancer death worldwide. Approximately three quarters of patients are diagnosed with disease limited to the bowel wall or surrounding lymph nodes. Over the past decade, significant progress has been made in the treatment of localized colon cancer. The use of adjuvant chemotherapy has improved prognosis in stage III disease, but much work remains to be done in optimizing adjuvant treatment. The FOLFOX4 regimen is now considered standard treatment for stage III disease. Combinations of irinotecan and 5-fluorouracil (5-FU) have not proven to be more effective than 5-FU/folinic acid. In stage II, the value of post-operative treatment remains controversial, but the identification of histopathological and molecular prognostic factors would allow selection of patients who can benefit from adjuvanttreatment. The inclusion of molecular targeted agents in combination regimens with cytotoxins, which have already proven effective in advanced disease, is the main field of development in the most recent protocols of adjuvant therapy.

Modeling interactions between Human Equilibrative Nucleoside Transporter-1 and other factors involved in the response to gemcitabine treatment to predict clinical outcomes in pancreatic ductal adenocarcinoma patients

BackgroundPancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive malignancy, characterized by largely unsatisfactory responses to the currently available therapeutic strategies. In this study we evaluated the expression of genes involved in gemcitabine uptake in a selected cohort of patients with PDAC, with well-defined clinical-pathological features.MethodsmRNA levels of hENT1, CHOP, MRP1 and DCK were evaluated by means of qRT-PCR in matched pairs of tumor and adjacent normal tissue samples collected from PDAC patients treated with gemcitabine after surgical tumor resection. To detect possible interaction between gene expression levels and to identify subgroups of patients at different mortality/progression risk, the RECursive Partitioning and Amalgamation (RECPAM) method was used.ResultsRECPAM analysis showed that DCK and CHOP were most relevant variables for the identification of patients with different mortality risk, while hENT1 and CHOP were able to identify subgroups of patients with different disease progression risk. Conclusion: hENT1, CHOP, MRP1 and DCK appear correlated to PDAC, and this interaction might influence disease behavior.

Poly (ADP-ribose) polymerase (PARP): rationale, preclinical and clinical evidences of its inhibition as breast cancer treatment.

Introduction: The chance to take advantage of genetic defects of cancer cells is a promising clinical tool in breast cancer therapy. Among the genetic aberrations, dysfunctions in DNA repair mechanisms are quite common and suitable for an attractive antitumor effect. Poly (ADP-ribose) polymerase I (PARP-1) is an enzyme with many functions in transcriptions and cell cycle regulation and in coordination of cellular response to DNA damage. Its involvement in tumorigenesis is witnessed by the overexpression found in different primary human tumors, where the increased enzymatic activity leads to cancer cell protection against DNA damage and instability. Therefore, activity of PARP and the opportunity to block it, mainly in cancer cells also deficient in other mechanisms of repair, are promising. Areas covered: In this review, areas covered include the main DNA repair mechanisms, the role of PARP enzymatic activity in diverse cell pathways as well as the preclinical and clinical data with PARP inhibitors. Expert opinion: Despite the theoretical role of PARP inhibitors as therapeutic strategy in specific subtypes of breast cancer (hereditary BRCA1/BRCA2 mutation-related cancers and sporadic triple-negative breast cancer), questions are still open. More exhaustive knowledge is needed about other important functions of PARPs in cellular homeostasis and about escape mechanisms of cancer cells to inhibitory effect of PARP inhibitors.

Optimized granulocyte colony-stimulating factor prophylaxis in adult cancer patients: from biological principles to clinical guidelines

Introduction: Chemotherapy-induced neutropenia, the depth and length of which are correlated to the risk of febrile neutropenia (FN) and neutropenia sepsis, remains a serious problem in medical oncology. Granulocyte colony-stimulating factors (G-CSF) stimulate the proliferation and survival of neutrophils and their precursors, thereby reducing the incidence, duration and severity of neutropenic events across a broad range of malignancies and regimens, often enabling the delivery of full chemotherapy dose intensity. Areas covered: In this review, areas covered include the physiologic role of G-CSF in granulopoiesis, as well as a related biological model of bone marrow kinetics after chemotherapy. Information relating to the application of clinical guidelines for optimization of prophylaxis of FN in adult cancer patients was critically summarized. The literature and pharmacological data were obtained through an electronic search. Expert opinion: There are relevant physiological and clinical evidences for the use of G-CSF to prevent FN and to ameliorate the myelotoxicities of cancer chemotherapy. In particular, biological models are in favor of the prophylactic rather than therapeutic use of G-CSF therapy. Use of a single dose of pegfilgrastim per cycle in appropriate patients provides a more convenient and potentially more effective strategy for assisting neutrophil recovery. While biosimilars may cost less, future developments in their regulation will need to address multiple issues. In the interim, physicians should remember that small differences in biochemical and biophysical characteristics might translate into differences in potency and immunogenic potential.

Combined modality treatments in pancreatic cancer

Introduction: Of all the carcinomas, pancreatic carcinoma (PC) has the highest mortality rate, with a 1- and 5-year survival rate of 25% and less than 5% respectively. This is regardless of the stage at diagnosis. Areas covered: In this review relevant literature assessing the evidence regarding preoperative and adjuvant chemoradiotherapy (CRT) is discussed. Furthermore, new therapeutic approaches are summarized, while the future direction regarding the multimodality approach to PC is also discussed. Expert opinion: The role of combined-modality therapy for PC is continuously evolving. There have been several recent developments, as well as the completion of major, multi-institutional clinical trials. One of the challenges for the busy clinician is to appreciate the variation in staging, surgical expertise, and application of either definitive CRT or neo-adjuvant CRT for local and/or borderline disease.

Changes in MicroRNAs Expression and Clinical Associations in Patients with Neuroendocrine Pancreatic Tumors

Context In a previously study, we analyzed associations between altered expression of 13 microRNAs (miR-145, miR-23a, miR-455-3p, miR-708, miR-151-5p, miR-30c, miR-let-7i, miR-199a-5p, miR-30a, miR-143, miR-21, miR-155*, and miR-31) and clinical variables in patients with pancreatic adenocarcinoma. Objective Here, expression levels of these miRNAs were analyzed to evaluate their possible associations with clinical-pathological features in patients underwent surgical resection for pancreatic neuroendocrine tumors (PETs). Methods miRNAs expression levels in tumors compared to matched-pairs non-cancerous tissue samples, were analyzed by using TaqMan MicroRNA Assay. Association analysis was performed by means of Spearman correlation coefficient and Mann-Whitney U-test. Results No significant association was found between miR-145, miR-23a, miR-455-3p, and miR-708 levels and patients sub-phenotypes. Conversely, miR-151-5p expression was inversely correlated with age at diagnosis (r s =-0.77, P=0.009), both miR-30a and miR-let-7i levels were positively associated with tumor size (r s =0.69, P=0.027 and r s =0.67, P=0.034), while over-expression of either miR-199a-5p and miR-30c was associate with male gender (P=0.046 and P=0.003). Further original finding was the association between miR-143, miR-21 and miR-155* levels and tumor mitotic index (P=0.04, P=0.0002, and P<0.0001, respectively), while expression of both miR-31 and miR-30c was associated with tumor proliferation index (P=0.003 and P=0.01, respectively). In addition, miRNAs expression levels were also found to be correlated with each others in PETs tissue samples. Conclusions These data suggest a prognostic significance for specific miRNAs in PETs. Understanding the associations between miRNAs expression levels could help identify novel regulatory network involved biology of PETs.

Evolution of Therapy Decision-Making Process for Advanced Non-Small Cell Lung Cancer

Advanced non-small cell lung cancer remains a lethal disease with poor prognosis. In the last decades results of systemic chemotherapy have reached a disappointing plateau without significant differences between the most widely employed third-generation regimens. Recent scientific evidence has shed new light on the management of advanced non-small cell lung cancer, especially for the important role of histological definition in therapy-planning process. The results of new biologic agents are also reported as are the promising data on pharmacogenomic-guided treatment.