Liquid biopsy for rectal cancer: a systematic review

Background: The management of locally advanced rectal cancer (RC) is an evolving clinical field where the multidisciplinary approach can reach its best, and liquid biopsy for obtaining tumor-derived component such as circulating tumor DNA (ctDNA) might provide complementary informations. Methods: A systematic review of studies available in literature of liquid biopsy in non-metastatic RC has been performed according to PRISMA criteria to assess the role of ctDNA as a diagnostic, predictive and prognostic biomarker in this setting. Results: Twenty-five publications have been retrieved, of which 8 full-text articles, 7 abstracts and 10 clinical trials. Results have been categorized into three groups: diagnostic, predictive and prognostic. Few but promising data are available about the use of liquid biopsy for early diagnosis of RC, with the main limitation of sensitivity due to low concentrations of ctDNA in this setting. In terms of prediction of response to chemoradiation, still inconclusive data are available about the utility of a pre-treatment liquid biopsy, whereas some studies report a positive correlation with a dynamic (pre/post-treatment) monitoring. The presence of minimal residual disease by ctDNA was consistently associated with worse prognosis across studies. Conclusions: The use of liquid biopsy for monitoring response to chemoradiation and assess the risk of disease recurrence are the most advanced potential applications for liquid biopsy in RC, with implications also in the context of non-operative management strategies

Alexithymia and personality traits of patients with inflammatory bowel disease

Psychological factors, specific lifestyles and environmental stressors may influence etiopathogenesis and evolution of chronic diseases. We investigate the association between Chronic Inflammatory Bowel Diseases (IBD) and psychological dimensions such as personality traits, defence mechanisms, and Alexithymia, i.e. deficits of emotional awareness with inability to give a name to emotional states. We analyzed a survey of 100 patients with IBD and a control group of 66 healthy individuals. The survey involved filling out clinical and anamnestic forms and administering five psychological tests. These were then analyzed by using a network representation of the system by considering it as a bipartite network in which elements of one set are the 166 individuals, while the elements of the other set are the outcome of the survey. We then run an unsupervised community detection algorithm providing a partition of the 166 participants into clusters. That allowed us to determine a statistically significant association between psychological factors and IBD. We find clusters of patients characterized by high neuroticism, alexithymia, impulsivity and severe physical conditions and being of female gender. We therefore hypothesize that in a population of alexithymic patients, females are inclined to develop psychosomatic diseases like IBD while males might eventually develop behavioral disorders

Stabilizing versus destabilizing the microtubules: A double-edge sword for an effective cancer treatment option?

Microtubules are dynamic and structural cellular components involved in several cell functions, including cell shape, motility, and intracellular trafficking. In proliferating cells, they are essential components in the division process through the formation of the mitotic spindle. As a result of these functions, tubulin and microtubules are targets for anticancer agents. Microtubule-targeting agents can be divided into two groups: microtubule-stabilizing, and microtubule-destabilizing agents. The former bind to the tubulin polymer and stabilize microtubules, while the latter bind to the tubulin dimers and destabilize microtubules. Alteration of tubulin-microtubule equilibrium determines the disruption of the mitotic spindle, halting the cell cycle at the metaphase-anaphase transition and, eventually, resulting in cell death. Clinical application of earlier microtubule inhibitors, however, unfortunately showed several limits, such as neurological and bone marrow toxicity and the emergence of drug-resistant tumor cells. Here we review several natural and synthetic microtubule-targeting agents, which showed antitumor activity and increased efficacy in comparison to traditional drugs in various preclinical and clinical studies. Cryptophycins, combretastatins, ombrabulin, soblidotin, D-24851, epothilones and discodermolide were used in clinical trials. Some of them showed antiangiogenic and antivascular activity and others showed the ability to overcome multidrug resistance, supporting their possible use in chemotherapy

Adipose-Derived Stem Cells from Fat Tissue of Breast Cancer Microenvironment Present Altered Adipogenic Differentiation Capabilities

Mesenchymal stem cells (MSCs) are multipotent cells able to differentiate into multiple cell types, including adipocytes, osteoblasts, and chondrocytes. The role of adipose-derived stem cells (ADSCs) in cancers is significantly relevant. They seem to be involved in the promotion of tumour development and progression and relapse processes. For this reason, investigating the effects of breast cancer microenvironment on ADSCs is of high importance in order to understand the relationship between tumour cells and the surrounding stromal cells. With the current study, we aimed to investigate the specific characteristics of human ADSCs isolated from the adipose tissue of breast tumour patients. We compared ADSCs obtained from periumbilical fat (PF) of controls with ADSCs obtained from adipose tissue of breast cancer- (BC-) bearing patients. We analysed the surface antigens and the adipogenic differentiation ability of both ADSC populations. C/EBP\u3b4 expression was increased in PF and BC ADSCs induced to differentiate compared to the control while PPAR\u3b3 and FABP4 expressions were enhanced only in PF ADSCs. Conversely, adiponectin expression was reduced in PF-differentiated ADSCs while it was slightly increased in differentiated BC ADSCs. By means of Oil Red O staining, we further observed an impaired differentiation capability of BC ADSCs. To investigate this aspect more in depth, we evaluated the effect of selective PPAR\u3b3 activation and nutritional supplementation on the differentiation efficiency of BC ADSCs, noting that it was only with strong differentiation stimuli that the process took place. Furthermore, we observed no response in BC ADSCs to the PPAR\u3b3 inhibitor T0070907, showing an impaired activation of this receptor in adipose cells surrounding the breast cancer microenvironment. In conclusion, our study shows an impaired adipogenic differentiation capability in BC ADSCs. This suggests that the tumour microenvironment plays a key role in the modulation of the adipose microenvironment located in the surrounding tissue

The role of microRNAs in driving EGFR-TKI resistance in NSCLC cell lines

Background: the inhibition of EGFR kinase activity by tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib and erlotinib, can result in improved response and prolonged progression-free survival (PFS) in NSCLC patients harboring sensitizing exon 19del and exon 21 L858R mutations. Unfortunately, almost all patients will develop resistance to EGFR-TKI, in particular T790M is the most frequent mutation. Nowadays, new methods are urgently needed for a rapid, cost-effective and non-invasive identification of biomarkers as a valuable tool for obtaining the genetic follow-up data during the course of the disease. Circulating microRNAs might represent a new precious biomarker for patients\u2019 monitoring. The study aimed to verify the association between microRNAs expression and EGFR mutational status in adenocarcinoma wt and EGFR-TKI sensitive mutated (del19) cells. Methods: EGFR wt and mutated adenocarcinoma cells (A549, HCC827), were cultured in RPMI1640 and incubated at 37C in 5% CO2. Cell viability before treatment was evaluated by MTT assay and then cells were treated with Erlotinib at growing concentration. MicroRNAs were extracted by using miRNeasy mini kit (QIAGEN). Nucleic acids quantity and quality was evaluated through the NanoDrop ND-2100 Bioanalyzer whereas integrity through the 2100 Bioanalyzer. MicroRNAs after retrotranscription were profiled through TaqMan Array Human MicroRNA Cards v2.0. Results: microRNAs extracted from A549 (wild-type) and HCC827 (del19) were profiled and differential expression analyzed at basal conditions (no treatment) using the wt cell as control. The miRNAs analysis highlighted that among the up-regulated microRNAs (miR-7, miR-18a, miR-106b, miR-200b, miR-505, miR-625), the miR-7 expression levels were 10 times higher, whereas among the down-regulated miRNAs (let-7f, miR-10b, miR-192, miR-193, miR-194, miR-767, miR-801), let-7f was 12 times lower. This signature may represent a valid start point for studying variations of the aforementioned miRNAs levels during TKIs treatment in order to demonstrate their involvement in inducing resistance. Conclusions: to outline molecular mechanisms responsible for resistance onset as consequence of TKIs treatment, the hypotetical role of miRNAs has been studied. The preliminary data, obtained so far only in cultured cell lines at basal conditions, would acquire higher relevance, if their involvement may be confirmed also in TKI-treated cells

Impact of hypoxia on chemoresistance of mesothelioma mediated by the proton-coupled folate transporter, and preclinical activity of new anti-LDH-A compounds

BACKGROUND: Expression of proton-coupled folate transporter (PCFT) is associated with survival of mesothelioma patients treated with pemetrexed, and is reduced by hypoxia, prompting studies to elucidate their correlation. METHODS: Modulation of glycolytic gene expression was evaluated by PCR arrays in tumour cells and primary cultures growing under hypoxia, in spheroids and after PCFT silencing. Inhibitors of lactate dehydrogenase (LDH-A) were tested in vitro and in vivo. LDH-A expression was determined in tissue microarrays of radically resected malignant pleural mesothelioma (MPM, N = 33) and diffuse peritoneal mesothelioma (DMPM, N = 56) patients. RESULTS: Overexpression of hypoxia marker CAIX was associated with low PCFT expression and decreased MPM cell growth inhibition by pemetrexed. Through integration of PCR arrays in hypoxic cells and spheroids and following PCFT silencing, we identified the upregulation of LDH-A, which correlated with shorter survival of MPM and DMPM patients. Novel LDH-A inhibitors enhanced spheroid disintegration and displayed synergistic effects with pemetrexed in MPM and gemcitabine in DMPM cells. Studies with bioluminescent hypoxic orthotopic and subcutaneous DMPM athymic-mice models revealed the marked antitumour activity of the LDH-A inhibitor NHI-Glc-2, alone or combined with gemcitabine. CONCLUSIONS: This study provides novel insights into hypoxia/PCFT-dependent chemoresistance, unravelling the potential prognostic value of LDH-A, and demonstrating the preclinical activity of LDH-A inhibitors

The prognostic role of KRAS and BRAF in patients undergoing surgical resection of colorectal cancer liver metastasis: a systematic review and meta-analysis

Background: Clinical trials investigated the potential role of both KRAS and BRAF mutations, as prognostic biomarkers, in colorectal cancer (CRC) patients who underwent surgical treatment of liver metastasis (CLM), showing conflicting results. This meta-analysis aims to review all the studies reporting survival outcomes (recurrence free survival (RFS), and/or overall survival (OS)) of patients undergoing resection of CLM, stratified according to KRAS and/or BRAF mutation status. Materials and Methods: Data from all published studies reporting survival outcomes (RFS and/or OS) of CRC patients who received resection of CLM, stratified by KRAS and/or BRAF mutation status were collected by searching in PubMed, Cochrane Library, American Society of Clinical Oncology and European Society of Medical Oncology meeting proceedings. Pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated for both the OS and/or RFS. Results: Seven eligible trials (1403 patients) were included. Pooled analysis showed that KRAS mutations predicted a significant worse both RFS (HR: 1.65; 95% CI: 1.23 \u2013 2.21) and OS (HR: 1.86; 95% CI: 1.51 \u2013 2.30) in patients who underwent surgical resection of CLM. BRAF mutations were also associated with a significant worse OS (HR: 3.90; 95% CI: 1.96 \u2013 7.73) in this subgroup of patients. Conclusion: This meta-analysis suggests both KRAS and BRAF mutations as negative prognostic biomarkers associated with worse survival outcomes in patients undergoing hepatic resection of CLM. Such evidences support the introduction of new treatment decision models, taking into account the tumor molecular profile in order to individualize both systemic and loco-regional treatment strategies

Effects of Dietary Restriction on Cancer Development and Progression

The effects of caloric restriction on tumor growth and progression are known for over a century. Indeed, fasting has been practiced for millennia, but just recently has emerged the protective role that it may exert toward cells. Fasting cycles are able to reprogram the cellular metabolism, by inducing protection against oxidative stress and prolonging cellular longevity. The reduction of calorie intake as well as short- or long-term fasting has been shown to protect against chronic and degenerative diseases, such as diabetes, cardiovascular pathologies, and cancer. In vitro and in vivo preclinical models showed that different restriction dietary regimens may be effective against cancer onset and progression, by enhancing therapy response and reducing its toxic side effects. Fasting-mediated beneficial effects seem to be due to the reduction of inflammatory response and downregulation of nutrient-related signaling pathways able to modulate cell proliferation and apoptosis. In this chapter, we will discuss the most significant studies present in literature regarding the molecular mechanisms by which dietary restriction may contribute to prevent cancer onset, reduce its progression, and positively affect the response to the treatments

Liquid Biopsy in Non-Small Cell Lung Cancer (NSCLC)

Lung cancer is the leading cause of cancer deaths worldwide. To date, the gold standard for the molecular analysis of a patient affected by NSCLC is the tissue biopsy. The discovery of activating mutations and rearrangements in specific genes has revolutionized the therapeutic approaches of lung cancer over the last years. For this reason, a strict \u201cmolecular follow-up\u201d is mandatory to evaluate patient\u2019s disease evolution. Indeed, liquid biopsy has raised as the \u201cnew ambrosia of researchers\u201d as it could help clinicians to identify both prognostic and predictive biomarkers in a more accessible way. Liquid biopsy analysis can be used in different moments starting from diagnosis to relapse, earning multiple clinical meanings, offering thus a noninvasive but valid method to detect actionable mutations. Although the implementation of both exosomes and CTCs in clinical practice is several steps back, new advances and discoveries make them, together with the ctDNA, a very promising tool. In the following chapter we will discuss the recent advances of liquid biopsy in NSCLC highlighting the possible clinical utility of CTCs, ctDNA and exosomes