The Blockade of Tumoral IL1ß-Mediated Signaling in Normal Colonic Fibroblasts Sensitizes Tumor Cells to Chemotherapy and Prevents Inflammatory CAF Activation.

Heterotypic interactions between newly transformed cells and normal surrounding cells define tumor's fate in incipient carcinomas. Once homeostasis has been lost, normal resident fibroblasts become carcinoma-associated fibroblasts, conferring protumorogenic properties on these normal cells. Here we describe the IL1ß-mediated interplay between cancer cells and normal colonic myofibroblasts (NCFs), which bestows differential sensitivity to cytotoxic drugs on tumor cells. We used NCFs, their conditioned media (CM), and cocultures with tumor cells to characterize the IL1ß-mediated crosstalk between both cell types. We silenced IL1ß in tumor cells to demonstrate that such cells do not exert an influence on NCFs inflammatory phenotype. Our results shows that IL1ß is overexpressed in cocultured tumor cells. IL1ß enables paracrine signaling in myofibroblasts, converting them into inflammatory-CAFs (iCAF). IL1ß-stimulated-NCF-CM induces migration and differential sensitivity to oxaliplatin in colorectal tumor cells. Such chemoprotective effect has not been evidenced for TGFß1-driven NCFs. IL1ß induces the loss of a myofibroblastic phenotype in NCFs and acquisition of iCAF traits. In conclusion, IL1ß-secreted by cancer cells modify surrounding normal fibroblasts to confer protumorogenic features on them, particularly tolerance to cytotoxic drugs. The use of IL1ß-blocking agents might help to avoid the iCAF traits acquisition and consequently to counteract the protumorogenic actions these cells.

Noncanonical TGFß Pathway Relieves the Blockade of IL1ß/TGFß-Mediated Crosstalk between Tumor and Stroma: TGFBR1 and TAK1 Inhibition in Colorectal Cancer.

PURPOSE: The aim of the study is blocking the recruitment of a protective stroma by altering the crosstalk between normal stromal cells and tumor cells for stripping tumors of the protection conferred by the microenvironment. EXPERIMENTAL DESIGN: A transcriptomic analysis of cocultured normal colonic fibroblasts and colorectal tumor cells was performed. We focused on the study of molecules that mediate the communication between both compartments and that entail fibroblasts' activation and the alteration of the sensitivity to chemotherapy. We identified targets for the blocking of the tumor-stroma interaction. Finally, we tested, in vivo, the blockade of the tumor-stroma interaction in orthotopic models derived from patients and in models of acquired resistance to oxaliplatin. RESULTS: IL1ß/TGFß1 are the triggers for fibroblasts' recruitment and conversion into carcinoma-associated fibroblasts (CAF) in colorectal cancer. CAFs then secrete proinflammatory factors that alter sensitivity in tumor cells, activating JAK/STAT and PI3KCA/AKT pathways. Blocking such crosstalk with a neutralizing IL1ß antibody and a TGFBR1 inhibitor is relieved by the TAK1-mediated activation of the noncanonical TGFß pathway, which induces a change in the cytokine/chemokine repertoire that maintains a sustained activation of AKT in tumor cells. TAK1 plus TGFBR1 inhibition blocks IL1ß/TGFß1-mediated fibroblast activation, decreasing the secretion of proinflammatory cytokines. In turn, tumor cells became more sensitive to chemotherapy. In vivo, the combination of a TAK1 inhibitor plus TGFBR1 inhibitor reduced the metastatic capacity of tumor cells and the recruitment of fibroblasts. CONCLUSIONS: Our findings provide a translational rationale for the inhibition of TAK1 and TGFBR1 to remove the chemoprotection conferred by CAFs.

Altered circadian rhythm and metabolic gene profile in rats subjected to advanced light phase shifts.

The circadian clock regulates metabolic homeostasis and its disruption predisposes to obesity and other metabolic diseases. However, the effect of phase shifts on metabolism is not completely understood. We examined whether alterations in the circadian rhythm caused by phase shifts induce metabolic changes in crucial genes that would predispose to obesity. Three-month-old rats were maintained on a standard diet under lighting conditions with chronic phase shifts consisting of advances, delays or advances plus delays. Serum leptin, insulin and glucose levels decreased only in rats subjected to advances. The expression of the clock gene Bmal 1 increased in the hypothalamus, white adipose tissue (WAT), brown adipose tissue (BAT) and liver of the advanced group compared to control rats. The advanced group showed an increase in hypothalamic AgRP and NPY mRNA, and their lipid metabolism gene profile was altered in liver, WAT and BAT. WAT showed an increase in inflammation and ER stress and brown adipocytes suffered a brown-to-white transformation and decreased UCP-1 expression. Our results indicate that chronic phase advances lead to significant changes in neuropeptides, lipid metabolism, inflammation and ER stress gene profile in metabolically relevant tissues such as the hypothalamus, liver, WAT and BAT. This highlights a link between alteration of the circadian rhythm and metabolism at the transcriptional level.

Different adaptation of the motor activity rhythm to chronic phase shifts between adolescent and adult rats.

Chronic phase shifts is a common feature in modern societies, which may induce sleep alterations and other health problems. The effects of phase shift on the circadian rhythms have been described to be more pronounced in old than in young animals. However, few works address the effects of chronic phase shifts during adolescence. Here we tested the development of the motor activity circadian rhythm of young rats under chronic phase shifts, which consisted on 6-h advances (A), 6h delays (D) or 6h advances and delays alternated every 5 days (AD) during the first 60 days after weaning. Moreover, the rhythmic pattern was compared to that of adult rats under the same lighting conditions. Results indicate that adolescent rats, independently on the lighting environment, developed a clear circadian rhythm, whose amplitude increased the first 50 days after weaning and showed a more stable circadian rhythm than adults under the same lighting conditions. In the case of A and AD groups, circadian disruption was observed only in adult rats. In all groups, the offset of activity correlated with light pattern better than the onset, and this correlation was always higher in the case of the rhythm of the pubertal rats. When AD groups were transferred to constant darkness, the group submitted to this condition during adolescence showed shorter period than that submitted in their adulthood. In conclusion, differently from adult rats, adolescent rats submitted to chronic phase shifts did not show circadian disruption and developed a single circadian rhythm, suggesting permanent changes in the circadian system.