Integrins are heterodimeric cell surface receptors that bind to different extracellular ligands depending on their composition and regulate all processes which enable multicellular life. In cancer, integrins trigger and play key roles in all the features that were once described as the Hallmarks of Cancer. In this review, we will discuss the contribution of integrins to these hallmarks, including uncontrolled and limitless proliferation, invasion of tumor cells, promotion of tumor angiogenesis and evasion of apoptosis and resistance to growth suppressors, by highlighting the latest findings. Further on, given the paramount role of integrins in cancer, we will present novel strategies for integrin inhibition that are starting to emerge, promising a hopeful future regarding cancer treatment.

Background: Nanoliposomal irinotecan (nal-IRI) plus 5-fluorouracil/leucovorin (5-FU/LV) is a novel treatment option for gemcitabine-pretreated metastatic pancreatic adenocarcinoma (PAC) patients, but real-world evidence is rare. Our aim was to determine the effectiveness and tolerability of this regimen in advanced PAC patients and to compare it with oxaliplatin plus fluoropyrimidines in the second-line setting after failure of gemcitabine. Methods: This is a retrospective single-center analysis of all patients who have been treated with nal-IRI plus 5-FU/LV. To compare its effectiveness with other second-line treatment options, all patients who had received oxaliplatin plus fluoropyrimidines after gemcitabine-based chemotherapy were also eligible for analysis. Results: Fifty-two patients were treated with nal-IRI plus 5-FU/LV between April 2016 and August 2018. The median progression-free survival (PFS) was 3.84 months and the median overall survival (OS) was 6.79 months. Median OS from the beginning of the treatment for advanced disease was 19.9 months. Median PFS in patients that received nal-IRI plus 5-FU/LV as second-line treatment after gemcitabine-based chemotherapy was 4.49 months whereas median PFS in a matched cohort of patients treated with oxaliplatin plus fluoropyrimidines was 3.44 months ( p = 0.007). Between these two groups the median OS of patients with CA 19-9 levels above the statistical median (⩾772.8 kU/l) differed significantly (9.33 versus 6.18 months, p = 0.038). Conclusion: Our data confirms the effectiveness of nal-IRI plus 5-FU/LV treatment as a well-tolerated regimen in the treatment of advanced PAC and extends available data on its use as a second-line treatment option when compared with oxaliplatin plus fluoropyrimidines.

BackgroundOverexpression of CD98hc (SLC3A2) occurs in a variety of cancers and is suspected to contribute to tumor growth. CD98, a heterodimeric transmembrane protein, physically associates with certain integrin β subunit cytoplasmic domains via its heavy chain, CD98hc. CD98hc regulates adhesion-induced intracellular signal transduction via integrins, thereby, affecting cell proliferation and clonal expansion. Disruption of CD98hc led to embryonic lethality in mice (E 3.5 and E 9.5) and CD98hc −/− embryonic stem cell transplantation failed to form teratomas, while CD98hc over-expression in somatic cells resulted in anchorage-independent growth. However, it is unclear whether interference with CD98hc expression tumor cell behavior.MethodsRenal cell cancer cell lines have been used to determine the effect of CD98hc expression on cancer cell behavior using cell adhesion, cell trans-migration and cell spreading assays. Flow cytometric analysis was performed to study the rate of apoptosis after detachment or serum starvation. shRNA-lentiviral constructs were used to stably knockdown or reconstitute full length or mutated CD98hc. The role of CD98 as a promotor of tumorigenesis was evaluated using an in in vivo tumor transplantation animal model. Immunohistochemical analysis was performed to analyze cell proliferation and CD98 expression in tumors.ResultsThis report shows that CD98hc silencing in clear cell renal cancer cells reverts certain characteristics of tumorigenesis, including cell spreading, migration, proliferation and survival in vitro, and tumor growth in vivo. Acquisition of tumorigenic characteristics in clear cell renal cancer cells occurred through the integrin binding domain of CD98hc. A CD98hc/integrin interaction was required for adhesion-induced sustained FAK phosphorylation and activation of the major downstream signaling pathways PI3k/Akt and MEK/ERK, while overexpression of a constitutive active form of FAK rescued the CD98hc deficiency.ConclusionsIn this study we demonstrate that loss of CD98hc blocks tumorigenic potential in renal cell cancer.