Anorexia and muscle wasting represent severe and disabling clinical features of cancer. Changes in inflammatory pathways may be responsible for interacting with central mechanisms that regulate appetite-centrally, and energy expenditure¿peripherally, and promote the activation of transcription factors and mediators involved in muscle derangement, including circulating muscle tissue-specific microRNAs (miRs).
Considering the high prevalence of nutritional changes in lung cancer, we aim to define:
1.mechanisms of anorexia identifying epigenetic modulation of inflammation
2.mechanisms of tissue wasting studying muscle tissue derangement by miRs profiling
3.the potential of epigenetic changes for preventing muscle mass tissue wasting, hypothesizing that epigenetic features and circulating miRs concentrations may be possible biomarkers for diagnosis, prognosis and therapeutic targets.
Anorexic and non-anorexic cancer patients and healthy individuals will be studied. Muscularity will be assessed by CT-scan. Plasma proinflammatory cytokines and their genes methylation and histone acetylation in peripheral blood cells will be analyzed and specific miRs expression profile for muscle tissue wasting will be assessed.
MiR dysregulation will be investigated in vivo. Gain and loss of function experiments will be performed in tumor-bearing mice in order to overexpress the downregulated miRs or to knock-down the upregulated ones. Since muscle-produced miRs can be secreted, muscle electroporation will produce both local and systemic effects, allowing to measure the direct anti-catabolic action in the muscle. We will test the effectiveness of epigenetic drugs in counteracting these epigenetic modifications in mice.
The results will be useful to treat cancer anorexia and muscle wasting aimed at reducing morbidity, mortality and improving the quality of life of lung cancer patients through more specific diagnostic tools and personalized nutritional and/or pharmacological interventions
Expected outcomes
1. To identify whether the anorexic/sarcopenic status of patients with lung cancer differ from those not characterized by such clinical status according to epigenetic patterns of specific gene pathways with a special focus on those linked to pro-inflammatory cytokines with a special focus on TNF-alpha, IL-1beta, IL-6, interferon gamma, PPARG (peroxisome proliferator-activated receptor gamma). This will allow to identify in an early stage the presence of cachexia and sarcopenia which characterize often the clinical course of the disease since the early phases of cancer journey.
2. To unravel possible novel genes and their underlined regulatory mechanisms related to the anorexic/sarcopenic condition
3. To define specific epigenetic features in PBMCs associated to anorexic/sarcopenic status of patients affected by lung cancer as a potentially useful molecular biomarker.
This approach will allow the identification of potentially useful miR targets to counteract cancer-induced muscle wasting. In a subsequent step we will assess the expression of known targets of the differentially expressed miRs, at both gene (by qPCR) and protein (by Western blotting) levels. The results obtained will provide information in terms of target expression on miR biological activity in both healthy and muscle wasting conditions.
The data that we plan to obtain by this project will be useful for further interventions to treat cancer associated anorexia and wasting disease by reducing morbidity, mortality and improving the quality of life of lung cancer patients through more specific diagnostic tools and personalized nutritional and/or pharmacological interventions.
Epigenetics plays an important role in modulating gene expression pathways and it is known to be linked to nutrition therefore we expect to unravel several unknown epigenetic mechanisms linked to the pathophysiology of anorexia and wasting disease in lung cancer development and progression. The fact that epigenetics may concurrently influence several oncogenic pathways on cancer cells and that epigenetic phenomena are potentially reversible makes the discovery of epigenetic features a promising diagnostic and possibly therapeutic target. In particular, there are increasing evidence supporting an enhanced activity when epigenetic priming agents are combined with other therapy such as chemotherapy and immunotherapy.
The appealing of epigenetic markers is also represented by the possibility to study them by fluids analysis detecting, for example, circulating nucleic acids epigenetically modulated during cell transformation. Regarding this, in lung cancer, non-invasive diagnostic procedure as the `liquid biopsy¿ has emerged as a source to characterize the tumor molecular background and became a crucial tool. Borrowing this scenario for epigenome, the epigenetic changes may be monitoring on fluids in order to: 1) detecting and monitoring tumors, 2) evaluating a potential prognostic and/or predictive impact during treatment, 3) correlating the epigenetic background with clinically relevant alterations influencing patients¿ outcome such anorexia/sarcopenia/cachexia.
Besides the biological implications in term of disease aggressiveness, lung cancer patients with anorexia and sarcopenia/cachexia at diagnosis have a worst prognosis related to several factors:
1) Limited access to standard therapeutic options (surgery in early stages, chemotherapy, etc.).
2) Decrease benefit from available treatments (including innovative options as targeted therapy and immunotherapy).
3) Exclusion from therapeutic opportunities as enrollment in clinical trials, able also to increase knowledge about the biological/molecular background of these patients.
Considering this, the early identification and targeting of those (epigenetic) factors enable to predict the onset of anorexia and sarcopenia and the possible evolution to cachexia therefore possibly increasing the efficacy of cancer therapy through different implications. Additionally, the present project may potentially impact on cancer research field unraveling new molecular mechanisms of cancer-related muscle tissue wasting and providing the rationale for anti-cachexia strategies based on the modulation of miRs or the use of epigenetic drugs. An effective treatment is also based on early diagnosis. In this light, this project explores the possibility to use miRs as early biomarkers of cachexia, thus allowing to predict the future onset of body wasting by correlating circulating miR/myomiR levels of lung cancer patients with parameters of cachexia (body weight loss, muscle wasting, protein breakdown) as well as with molecular markers of muscle wasting to improve nutritional and metabolic status aimed at ameliorating response to anti-cancer treatment and reducing morbidity and mortality.