Randomized phase 2 trial of pemetrexed, pemetrexed/bevacizumab, and pemetrexed/carboplatin/bevacizumab in patients with stage IIIB/IV non-small cell lung cancer and an Eastern Cooperative Oncology Group performance status of 2.

BACKGROUND: The best treatment for patients with advanced non-small cell lung cancer (NSCLC) and a poor performance status is not well defined. In this phase 2 trial, patients were randomized to receive treatment with either single-agent pemetrexed or 1 of 2 combination regimens. METHODS: Patients with newly diagnosed, histologically confirmed nonsquamous NSCLC and an Eastern Cooperative Oncology Group (ECOG) performance status of 2 were stratified by age and serum albumin level and were randomized (1:1:1) to 1 of 3 regimens: pemetrexed (arm 1), pemetrexed and bevacizumab (arm 2), or pemetrexed, carboplatin, and bevacizumab (arm 3). The response to treatment was assessed every 2 cycles; responding and stable patients continued treatment until progression or unacceptable toxicity. RESULTS: One hundred seventy-two patients were randomized, 162 patients began the study treatment, and 146 patients completed 2 cycles and were evaluated for their response. The median progression-free survival (PFS) was 2.8 months in arm 1, 4.0 months in arm 2, and 4.8 months in arm 3. The overall response rates were 15% in arm 1, 31% in arm 2, and 44% in arm 3. The overall survival was similar in the 3 treatment arms. All 3 regimens were relatively well tolerated. Patients receiving bevacizumab had an increased incidence of hypertension, proteinuria, and bleeding episodes, but most events were mild or moderate. CONCLUSIONS: All 3 regimens were feasible for patients with advanced NSCLC and an ECOG performance status of 2. The addition of bevacizumab to pemetrexed increased the overall response rate. The efficacy of pemetrexed/carboplatin/bevacizumab (median PFS, 4.8 months) approached the prespecified study PFS goal of 5 months. Larger studies will be necessary to define the role of bevacizumab in addition to standard pemetrexed and carboplatin in this population. Cancer 2018;124:1982-91. © 2018 American Cancer Society.

Slug is a downstream mediator of transforming growth factor-beta1-induced matrix metalloproteinase-9 expression and invasion of oral cancer cells.

Members of Snail family of transcription factors play an important role in oral cancer progression by inducing epithelial-mesenchymal transition, by promoting invasion and by increasing matrix metalloproteinase (MMP) expression. Although Snail (Snai1) is the best characterized and the most extensively studied member of this family, the role and regulation of Slug (Snai2) in oral cancer progression is less well understood. In this report, we show that transforming growth factor-beta1 (TGF-beta1) increases Slug levels in tert-immortalized oral keratinocytes and in malignant oral squamous cell carcinoma (OSCC) cells. Inhibiting ERK1/2 signaling, but not PI3-kinase signaling, blocked TGF-beta1-induced Slug expression in the malignant UMSCC1 cells. To further examine the role of Slug in OSCC progression, we generated UMSCC1 cells with inducible expression of Slug protein. Induction of Slug in UMSCC1 cells did not repress E-cadherin levels or regulate individual movement of UMSCC1 cells. Instead, Slug enhanced cohort migration and Matrigel invasion by UMSCC1 cells. Slug increased MMP-9 levels and MMP-9-specific siRNA blocked Slug-induced Matrigel invasion. Interestingly, Slug-specific siRNA attenuated TGF-beta1-induced MMP-9 expression and Matrigel invasion. These data demonstrate that TGF-beta1 increases Slug via ERK1/2 signaling, and thereby contributes to OSCC progression.

Differential growth factor regulation of N-cadherin expression and motility in normal and malignant oral epithelium.

Aberrant expression of N-cadherin is associated with tumor progression in squamous cell carcinomas (SCCs). Consequently, we examined the regulation of N-cadherin by TGFbeta1, an important mediator of keratinocyte and SCC function. N-cadherin expression was increased in oral SCC (OSCC) cell lines, regulating motility and correlating with TGFbeta1 production. Moreover, in normal keratinocytes TGFbeta1 increased expression of N-cadherin to regulate motility. TGFbeta1-mediated N-cadherin expression in the oral keratinocytes was blocked using siRNA targeting Smads. Unexpectedly, we found that EGF blocked TGFbeta1-mediated N-cadherin expression in oral keratinocytes and not in OSCC cells. Mechanistically, EGF enhanced Smad phosphorylation in the linker region, and attenuated TGFbeta1-mediated phosphorylation of Smad at the C-terminus, localization of Smad to the nucleus as well as Smad-driven promoter activity exclusively in oral keratinocytes but not in OSCC cells. The effect of EGF on TGFbeta1-mediated Smad-driven promoter activity and N-cadherin expression was reversed when activation of ERK1/2 was blocked. Although EGF and TGFbeta1 independently promoted migration of both oral keratinocytes and OSCC cells, EGF decreased TGFbeta1-mediated migration of oral keratinocytes but enhanced migration of OSCC cells. Together, these data support a model wherein EGF signaling has an important negative regulatory role on TGFbeta1-mediated N-cadherin expression and motility in normal oral keratinocytes, and in which loss of this regulatory mechanism accompanies malignant transformation of the oral epithelium.

Transforming growth factor-beta 1 promotes matrix metalloproteinase-9-mediated oral cancer invasion through snail expression.

Oral squamous cell carcinoma (OSCC), which is the most common malignancy of the oral cavity, is often associated with local and regional invasion. Increased expression of matrix metalloproteinase-9 (MMP-9) is correlated with invasive behavior of OSCC. Because transforming growth factor beta1 (TGF-beta1) is up-regulated in OSCC tumors, we examined the relationship between TGF-beta1 signaling and MMP-9 in human OSCC specimens. Evaluation of human specimens showed that tumors with enhanced TGF-beta1 signaling also showed increased MMP-9 expression. Because the transcription factor Snail has been determined to be a key mediator of TGF-beta1 signaling, we evaluated the role of Snail in TGF-beta1-mediated MMP-9 expression. Initially, we examined the extent to which TGF-beta1 regulated Snail expression in oral keratinocytes and in OSCC cell lines. TGF-beta1 enhanced Snail expression in a majority of the cell lines examined, with the largest induction of Snail detected in UMSCC1 cells. Interestingly, overexpression of Snail in UMSCC1 cells enhanced MMP-9 and tissue inhibitor of metalloproteinase-1 protein levels. Despite the increase in the tissue inhibitor of metalloproteinase-1 protein, there was a net increase in the pericellular proteolytic activity as shown by enhanced MMP-9-dependent Matrigel invasion. Moreover, Snail-specific siRNA blocked TGF-beta1-induced MMP-9 expression and Matrigel invasion. In addition, Snail increased Ets-1 levels and Ets-1-specific siRNA blocked both Snail- and TGF-beta1-mediated MMP-9 expression and Matrigel invasion. Thus, these data show that Snail functions as a molecular mediator of TGF-beta1-regulated MMP-9 expression by increasing Ets-1 and thereby contributing to oral cancer progression.