Temporal evolution of programmed death-ligand 1 expression in patients with non-small cell lung cancer

Background/Aims@#Programmed death-ligand 1 (PD-L1) expression, a validated predictive biomarker for anti-PD-1/PD-L1 inhibitors, is reported to change over time. This poses challenges during clinical application in non-small cell lung cancer. @*Methods@#This study included patients with non-small cell lung cancer who underwent surgery or biopsy and evaluation of PD-L1 expression in tumor cells via immunohistochemistry more than twice. We set the threshold of PD-L1 positivity to 10% and categorized patients into four groups according to changes in PD-L1 expression. Clinicopathologic information was collected from medical records. Statistical analyses, including Fisher’s exact test and log-rank test, were performed. @*Results@#Of 109 patients, 38 (34.9%) and 45 (41.3%) had PD-L1 positivity in archival and recent samples, respectively. PD-L1 status was maintained in 78 (71.6%) patients, but changed in 31 (28.4%), with 19 (17.4%) from negative to positive. There were no significant differences in characteristics between patients who maintained PD-L1 negativity and whose PD-L1 status changed from negative to positive. Patients harboring PD-L1 positivity in either archival or recent samples achieved better responses (p = 0.129) and showed longer overall survival than those who maintained PD-L1 negativity when they received immune checkpoint inhibitors after platinum failure (median overall survival 14.4 months vs. 4.93 months; hazard ratio, 0.43; 95% confidence interval, 0.20 to 0.93). @*Conclusions@#PD-L1 status changed in about one-fourth of patients. PD-L1 positivity in either archival or recent samples was predictive of better responses to immune checkpoint inhibitors. Therefore, archival samples could be used for assessment of PD-L1 status. The need for new biopsies should be decided individually.

Astragalin Inhibits Nuclear Factor-κB Signaling in Human ColonicEpithelial Cells and Attenuates Experimental Colitis in Mice

Background/Aims@#Astragalin (kaempferol-3-O-β-D-glucoside) is a flavonoid isolated from the leaves of persimmon or Rosa agrestis. Astragalin exhibits various anti-inflammatory properties; however, little is known about its therapeutic potential for inflammatory bowel disease (IBD). This study aims to investigate the anti-inflammatory effect of astragalin via blockade of the nuclear factor κB (NF-κB) signaling pathway in human colonic epithelial cells and a murine colitis model. @*Methods@#HCT-116 and HT-29 human colonic epithelial cells were pretreated with astragalin and stimulated with tumor necrosis factor-α (TNF-α). Cell viability was assessed by the MTS assay. Real-time reverse transcription polymerase chain reaction was used to analyze the messenger RNA expression of the inflammatory cytokines interleukin (IL)-6 and IL-8. The effect of astragalin on the NF-κB pathway was evaluated by Western blot analysis of inhibitor of NF-κB alpha (IκBα) phosphorylation/degradation and by electrophoretic mobility shift assay. Dextran sulfate sodium (DSS)-induced acute murine colitis model was used for in vivo experiments. @*Results@#Astragalin strongly suppressed the expression of proinflammatory cytokines in human colonic epithelial cells in a dose-dependent manner. Western blot analysis showed that astragalin inhibited IκBα phosphorylation/degradation. Additionally, astragalin reduced the DNA binding ac-tivity of NF-κB. Astragalin alleviated colon shortening and improved the pathologic scores in DSSinduced acute murine colitis model. Furthermore, astragalin reduced the level of phosphorylated IκBα and decreased the production of the inflammatory cytokines IL-6, IL-8, and TNF-α in the DSS-treated colon mucosa. @*Conclusions@#Astragalin exerted an anti-inflammatory effect through NF-κB pathway inhibition and attenuated murine colitis. Astragalin is thus a potential therapeutic agent for IBD.

Temporal evolution of programmed death-ligand 1 expression in patients with non-small cell lung cancer

Background/Aims@#Programmed death-ligand 1 (PD-L1) expression, a validated predictive biomarker for anti-PD-1/PD-L1 inhibitors, is reported to change over time. This poses challenges during clinical application in non-small cell lung cancer. @*Methods@#This study included patients with non-small cell lung cancer who underwent surgery or biopsy and evaluation of PD-L1 expression in tumor cells via immunohistochemistry more than twice. We set the threshold of PD-L1 positivity to 10% and categorized patients into four groups according to changes in PD-L1 expression. Clinicopathologic information was collected from medical records. Statistical analyses, including Fisher’s exact test and log-rank test, were performed. @*Results@#Of 109 patients, 38 (34.9%) and 45 (41.3%) had PD-L1 positivity in archival and recent samples, respectively. PD-L1 status was maintained in 78 (71.6%) patients, but changed in 31 (28.4%), with 19 (17.4%) from negative to positive. There were no significant differences in characteristics between patients who maintained PD-L1 negativity and whose PD-L1 status changed from negative to positive. Patients harboring PD-L1 positivity in either archival or recent samples achieved better responses (p = 0.129) and showed longer overall survival than those who maintained PD-L1 negativity when they received immune checkpoint inhibitors after platinum failure (median overall survival 14.4 months vs. 4.93 months; hazard ratio, 0.43; 95% confidence interval, 0.20 to 0.93). @*Conclusions@#PD-L1 status changed in about one-fourth of patients. PD-L1 positivity in either archival or recent samples was predictive of better responses to immune checkpoint inhibitors. Therefore, archival samples could be used for assessment of PD-L1 status. The need for new biopsies should be decided individually.

Ubiquitin E3 Ligase Pellino-1 Inhibits IL-10-mediated M2c Polarization of Macrophages, Thereby Suppressing Tumor Growth

Pellino-1 is a ubiquitin (Ub) E3 ligase that plays a role in M1, but not M2a polarization of macrophages. However, it is unknown whether Pellino-1 regulates IL-10-mediated M2c polarization of macrophages. Here, we found that Pellino-1 attenuated tumor growth by inhibiting M2c polarization of macrophages. Upon IL-10 stimulation, Pellino-1-deificient bone marrow-derived macrophages (BMDMs) showed higher expression of M2c markers, but not M2a, and M2b markers than wild-type (WT) BMDMs, indicating that Pellino-1 inhibits M2c polarization of macrophages. Pellino-1-deficient BMDMs exhibited a defect in mitochondria respiration, but enhancement of glycolysis during M2c polarization. During M2c polarization of macrophages, Pellino-1 increased STAT1 phosphorylation via K63-linked ubiquitination of IL-1 receptor associated kinase 1 (IRAK1). Furthermore, Lysm-CrePellino-1(fl/fl) mice showed enhancement of tumor growth via regulating M2c polarization of tumor-associated macrophages. These results demonstrate that Pellino-1 inhibits IL-10-induced M2c macrophage polarization via K63-linked ubiquitination of IRAK1 and activation of STAT1, thereby inhibiting tumor growth in vivo.

Impact of Mucin Proportion in the Pretreatment MRI on the Outcomes of Rectal Cancer Patients Undergoing Neoadjuvant Chemoradiotherapy / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The purpose of this study was to evaluate treatment response to neoadjuvant chemoradiotherapy (CRT) with regard to mucin status in pathology and pretreatment magnetic resonance imaging (MRI) in locally advanced rectal cancer. MATERIALS AND METHODS: Between 2003 and 2011, 306 patients with locally advanced rectal cancer received neoadjuvant CRT followed by surgery, and mucinous adenocarcinoma (MAC) was found in 27 (8.8%). All MAC patients had MRI before and after CRT and mucin proportion at MRI was measured. Therapeutic response was assessed by pathology after total mesorectal excision. To determine the optimal cut-off for mucin proportion in predicting good CRT response (near total or total regression) and negative circumferential resection margin (CRM), the receiver-operating characteristic analysis was performed. RESULTS: After neoadjuvant CRT, overall downstaging occurred in 44.4% of MAC and 72.4% of non-MAC (p=0.001), and positive CRM (≤1 mm) was observed more frequently in MAC (p<0.001). The optimal threshold for treatment response was 30% for mucin proportion, and there are nine with low mucin proportion (<30%) and 18 with high mucin proportion (≥30%) in pretreatment MRI. Negative CRM and tumor downstaging occurred more common in patients with mucin <30%, although statistically insignificant (p=0.071 and p=0.072, respectively). Regarding oncologic outcomes, lower mucin proportion in pretreatment MRI was associated with better disease-free and overall survival in MAC group (p=0.092 and 0.056, respectively), but the difference did not reach statistical significance. CONCLUSION: Poor treatment outcome with neoadjuvant CRT was observed in patients with MAC, especially those with high mucin proportion at pretreatment MRI.

Alterations in PD-L1 Expression Associated with Acquisition of Resistance to ALK Inhibitors in ALK-Rearranged Lung Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The purpose of this study was to evaluate the relationships between the resistance of anaplastic lymphoma kinase (ALK)‒positive non-small cell lung cancer (NSCLC) to ALK inhibitors and the programmed cell death-1/programmed cell death–ligand 1 (PD-L1) pathway, we evaluated alterations in PD-L1 following acquisition of resistance to ALK inhibitors in ALK-positive lung cancer. MATERIALS AND METHODS: We established ALK inhibitor-resistant cell lines (H3122CR1, LR1, and CH1) by exposing the parental H3122 ALK-translocated NSCLC cell line to ALK inhibitors. Then, the double-resistant cell lines H3122CR1LR1 and CR1CH1 were developed by exposing the H3122CR1 to other ALK inhibitors. We compared the alterations in PD-L1 expression levels using western blotting, flow cytometry, and quantitative polymerase chain reaction. We also investigated gene expression using RNA sequencing. The expression of PD-L1 in the tumors from 26 ALK-positive metastatic NSCLC patients (11 ALK inhibitor-naïve and 15 ALK inhibitor-resistant patients) was assessed by immunohistochemistry and analyzed. RESULTS: PD-L1 was expressed at higher levels in ALK inhibitor-resistant cell lines than in the ALK inhibitor-naïve parental cell line at the total protein, surface protein, and mRNA levels. Furthermore, PD-L1 expression in the double-resistant cell lines was much higher than that in the single resistant cell lines. RNA sequencing demonstrated that expression of immune-related genes were largely involved in ALK inhibitor resistance. The mean value of the PD-L1 H-score was 6.5 pre-treatment and 35.0 post-treatment, and the fold difference was 5.42 (p=0.163). CONCLUSION: PD-L1 expression increased following acquisition of ALK inhibitor resistance in ALK-positive NSCLC cell lines and tumors.

Benign Indolent CD56-Positive NK-Cell Lymphoproliferative Lesion Involving Gastrointestinal Tract in an Adolescent

No abstract available.