In non-metastatic non-small-cell lung cancer (NSCLC), outcomes remain poor. Adjuvant chemotherapies provide a limited improvement in disease-free survival. Recent exploratory studies on early-stage NSCLC show that immunotherapy given according to Programmed Death–Ligand 1 expression generates variable results, emphasizing a need to improve tumor characterization. We aimed to conjointly assess NSCLC, the expression of PD–L1, and epithelial–mesenchymal transition, frequently involved in tumor aggressiveness. 188 resected NSCLCs were analyzed. Among 188 patients with curatively resected NSCLC, 127 adenocarcinomas and 61 squamous cell carcinomas were stained for PD–L1 and vimentin expression. Overall survival has been compared regarding PD–L1 and vimentin statuses both separately and conjointly in Tumor Cancer Genome Atlas databases. PD–L1 and vimentin higher expressions were strongly associated (OR = 4.682, p < 0.0001). This co-expression occurred preferentially in tumors with lymph node invasion (p = 0.033). PD–L1 was significantly associated with high EMT features. NSCLC harboring both PD–L1^high/vimentin^high expressions were significantly associated with poor overall survival (p = 0.019). A higher co-expression of vimentin and PD–L1 was able to identify patients with worse outcomes. Similar to an important prognostic marker in NSCLC, this tandem marker needs to be further presented to anti-PD–L1 immunotherapies to improve outcome.

Invasiveness and metastatic capacity of tumor cells have been related to increased expression and activation of gelatinase‐A (MMP‐2). 9‐octadecenoic acid (oleic acid, OA), a long‐chain cis‐unsaturated fatty acid, has been shown to partially inhibit the formation of lung metastatic colonies in an ex vivo model of implantation of metastatic cells into nude mice. Reduction of metastasis formation was suggested to be due to a decrease of MMP‐2 activity in tumor tissue extracts. Since regulation of MMP‐2 activity occurs at different levels, including gene expression, pro‐enzyme activation and finally active enzyme inhibition, we here investigated the precise level of the inhibitory effect of OA on MMP‐2 activity by oncogene‐transformed human bronchial epithelial cells (BZR cells). OA, at the dose of 5 × 10⁻⁵ M, was shown to inhibit by 50% MMP‐2 activity released from BZR cells. Northern‐blot analysis of mRNA encoding MMP‐2, MT1‐MMP, the physiological activator of MMP‐2, and TIMP‐2, the natural inhibitor of MMP‐2, revealed that OA did not alter the steady‐state levels of MMP‐2, MT1‐MMP and TIMP‐2 mRNA. Also, gelatin zymography demonstrated that the extent of MMP‐2 activation was not modified by OA treatment. On the contrary, OA could inhibit the fluorogenic quenching substrate (7‐methoxycoumarin‐4‐yl)acetyl‐L‐Pro‐Leu‐Gly‐Leu‐[N‐3‐(2,4‐dinitrophenyl)‐L‐2, 3‐diaminopropionyl]‐Ala‐Arg‐NH₂ (Mca‐Pro‐Leu‐Gly‐Leu‐Dpa‐Ala‐Arg‐NH₂) hydrolysis by recombinant MMP‐2 with K_i = 4.3 μM. These data suggest that the beneficial influence of OA on the formation of lung metastatic colonies was independent of its influence on MMP‐2 expression and/or activation, but could be attributed to inhibition of MMP‐2 activity. Int. J. Cancer 80:751–755, 1999.

MMP‐2 (gelatinase A) has been associated with the invasive potential of many cancer cells both in vitro and in vivo. It is now becoming clear that the activation of this enzyme might be a key step in tumor invasion. This activation process has been shown to be a membrane‐associated pathway inducible by various agents such as collagen type I, concanavalin A or TGF‐β, but its physiological regulation is still largely unresolved. MT‐MMP was recently discovered and described as a potential gelatinase‐A activator. In the present study, we investigated the expression of MT‐MMP (membrane‐type metalloproteinase) in cervical cancer cells both in vitro and in vivo. Comparing several in vitro‐transformed cervical cell lines, previously shown to display different invasive potentials, our results showed that the ability of cells to overexpress MT‐MMP mRNA following ConA induction correlated with their ability to activate gelatinase A and with a highly invasive behavior. Moreover, using immunohistochemistry and in situ hybridization, we found a higher level of MT‐MMP expression in invasive cervical carcinoma and lymphnode metastases compared to its expression in non‐invasive CIN III lesions. Our in vivo observations also clearly demonstrated a cooperation between stromal and tumor cells for the production of MT‐MMP. Taken together, our results clearly correlated high level MT‐MMP expression with invasiveness, and thus suggested that MT‐MMP might play a crucial role in cervical tumor invasion. © 1996 Wiley‐Liss, Inc.