Metabolic and histomorphological changes of adipose tissue in cachexia

[Cancer-associated cachexia: an unresolved disease]

Cachexia is a systemic wasting condition associated to advanced phases of many cancers, which contributes to significant morbidity and mortality. It is mainly characterized by involuntary weight loss due to muscle wasting often associated with loss of adipose tissue, possibly leading to inanition and death, without treatment to date. Symptomatology covers a complex array of disorders (fatigue, inflammation, pain, anorexia, depression) related to multisystemic impairments progressively affecting numerous organs and tissues (muscle, adipose tissue, brain, immune system, gastrointestinal tract). The mechanisms of induction and progression of the disease, still poorly understood, involve inflammatory, metabolic, and neuroendocrine drivers, triggered by a variety of mediators originating from tumor, tumor-host interactions, and inter-organ crosstalk.

Assessment of lipolysis biomarkers in adipose tissue of patients with gastrointestinal cancer

BACKGROUND

Adipose tissue metabolism may be impaired in patients with cancer. In particular, increased lipolysis was described in cancer-promoting adipose tissue atrophy. For this reason, we assessed the expression of the lipolysis-associated genes and proteins in subcutaneous adipose tissue (SAT) of gastrointestinal (GI) cancer patients compared to controls to verify their involvement in cancer, among different types of GI cancers, and in cachexia.

METHODS

We considered patients with GI cancer (gastric, pancreatic, and colorectal) at their first diagnosis, with/without cachexia, and controls with benign diseases. We collected SAT and total RNA was extracted and ATGL, HSL, PPARα, and MCP1 were analyzed by qRT-PCR. Western blot was performed to evaluate CGI-58, PLIN1 and PLIN5.

RESULTS

We found higher expression of ATGL and HSL in GI cancer patients with respect to controls (p ≤ 0.008) and a trend of increase for PPARα (p = 0.055). We found an upregulation of ATGL in GI cancer patients with cachexia (p = 0.033) and without cachexia (p = 0.017) vs controls. HSL was higher in patients with cachexia (p = 0.020) and without cachexia (p = 0.021), compared to controls. ATGL was upregulated in gastric cancer vs controls (p = 0.014) and higher HSL was found in gastric (p = 0.008) and in pancreatic cancer (p = 0.033) vs controls. At the protein level, we found higher CGI-58 in cancer vs controls (p = 0.019) and in cachectic vs controls (p = 0.029), as well as in gastric cancer vs controls (p = 0.027).

CONCLUSION

In our cohort of GI cancer patients, we found a modulation in the expression of genes and proteins involved in lipolysis, and differences were interestingly detected according to cancer type.