RESUMO
BACKGROUND: RAS mutations are the only validated biomarkers in metastatic colorectal cancer (mCRC) for anti-epidermal growth factor receptor (EGFR) therapy. Limited clinical information is available on AXL expression, marker of epithelial to mesenchymal transition, in mCRC. METHODS: AXL was retrospectively assessed by immunohistochemistry in 307 patients. RAS wild-type (WT) patients (N = 136) received first-line anti-EGFR-based therapy; RAS mutant patients (N = 171) received anti-angiogenic-based regimens. Preclinical experiments were performed using human RAS WT CRC cell lines and xenograft models. AXL RNA levels were assessed in a cohort of patients with available samples at baseline and at progression to anti-EGFR treatment and in the GSE5851 dataset. RESULTS: AXL was expressed in 55/307 tumour tissues, correlating with worse survival in the overall population (AXL-positive, 23.7 months; AXL-negative, 30.8 months; HR, 1.455, P = 0.032) and in RAS WT patients (AXL-positive, 23.0 months; AXL-negative, 35.8 months; HR,1.780, P = 0.032). Progression-free survival (PFS) in the RAS WT cohort was shorter in the AXL-positive cohort (6.2 months versus 12.1 months; HR, 1.796, P = 0.013). Three-dimensional cultures obtained from a patient following anti-EGFR therapy resulted AXL-positive, showing resistance to anti-EGFR drugs and sensitivity to AXL inhibition. AXL transfection in CRC cell lines induced AXL overexpression and resistance to the EGFR blockade. At progression to cetuximab, 2/10 SW48-tumour xenograft mice showed AXL expression. Consistently, AXL RNA levels increased in 5/7 patients following anti-EGFR therapy. Moreover, in the GSE5851 dataset higher AXL RNA levels correlated with worse PFS with cetuximab in KRAS-exon2 WT chemorefractory patients. CONCLUSIONS: AXL is a marker of poor prognosis in mCRC with consistent clinical and preclinical evidences of involvement in primary and acquired resistance to anti-EGFR drugs in RAS WT patients.
Assuntos
Neoplasias Colorretais/tratamento farmacológico , Receptores ErbB/antagonistas & inibidores , Genes ras , Proteínas Proto-Oncogênicas/análise , Receptores Proteína Tirosina Quinases/análise , Animais , Biomarcadores , Linhagem Celular Tumoral , Neoplasias Colorretais/química , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Resistencia a Medicamentos Antineoplásicos , Humanos , Camundongos , Metástase Neoplásica , Ensaios Antitumorais Modelo de Xenoenxerto , Receptor Tirosina Quinase AxlRESUMO
BACKGROUND: In accordance with the scientific literature heavy alcohol consumption (>50g per day) represents a risk factor for several diseases development, including cancer. However, the oncogenic role of light alcohol drinking (<12.5g per day) is still unknown. OBJECTIVE: To assess the scientific knowledge about light alcohol consumption and the risk of malignancy onset. METHODS: To collect the scientific evidences regarding this topic the keywords "light alcohol drinking", "light alcohol consumption" and "cancer", were used. Papers published during the last 15 years were analyzed, in order to select the most recent evidence. Meta-analyses with well-defined levels of alcohol intake were included in the present review. Other studies that focused on biochemical, molecular and genetic aspects, as well as duplicate articles, were excluded. RESULTS: Twenty-nine large, meta-analyses were included in this review. Light alcohol drinking was not associated with an increased risk of cancer occurrence, with the exception of breast and prostate cancer and melanoma. Furthermore, a possible protective role of light alcohol consumption on the development of bladder, kidney and ovarian cancer and Non Hodgkin Lymphoma was observed. CONCLUSION: Light alcohol drinking was not associated with the development of several malignancies, except for a light increase of melanoma, breast cancer in women and prostate cancer in men.