Efficiency of eSource Direct Data Capture in Investigator-Initiated Clinical Trials in Oncology.

BACKGROUND: Clinical trials have become larger and more complex. Thus, eSource should be used to enhance efficiency. This study aimed to evaluate the impact of the multisite implementation of eSource direct data capture (DDC), which we define as eCRFs for direct data entry in this study, on efficiency by analyzing data from a single investigator-initiated clinical trial in oncology. METHODS: Operational data associated with the targeted study conducted in Japan was used to analyze time from data occurrence to data entry and data finalization, and number of visits to the site and time spent at the site by clinical research associates (CRAs). Additionally, simulations were performed on the change in hours at the clinical sites during the implementation of eSource DDC. RESULTS: No difference in time from data occurrence to data entry was observed between the DDC and the transcribed data fields. However, the DDC fields could be finalized 4 days earlier than the non-DDC fields. Additionally, although no difference was observed in the number of visits for source data verification (SDV) by CRAs, a comparison among sites that introduced eSource DDC and those that did not showed that the time spent at the site for SDV was reduced. Furthermore, the simulation results indicated that even a small amount of data to be collected or a small percentage of DDC-capable items may lead to greater efficiency when the number of subjects per site is significant. CONCLUSIONS: The implementation of eSource DDC may enhance efficiency depending on the study framework and type and number of items to be collected.

Pre-existing autoimmune disease as a risk factor for immune-related adverse events in cancer patients receiving immune checkpoint inhibitors.

Immune checkpoint inhibitors (ICIs) have been widely used as standard therapies for various cancers. However, in 20-30% of cases, ICIs can lead to immune-related adverse events (irAEs), which sometimes require discontinuation of treatment. Due to the increased risk of irAEs, patients with pre-existing autoimmune diseases (AI) are often advised against receiving ICIs. However, there has not been sufficient objective risk assessment for AI. In our study, we conducted logistic regression analysis to assess the risk of irAEs by analyzing 478 cases that received anti-PD-(L)1 Ab and/or anti-CTLA4 Ab at our hospital between April 3, 2017, and May 24, 2022. Among these cases, 28 (5.9%) had pre-existing AI. We selected several independent factors for analysis: gender, age, performance status (PS), cancer type, type of ICI, type of combined anti-cancer agents, best overall response, and pre-existing AI. The adjusted odds ratio (OR) of AI for irAE occurrence was 2.52 [95% CI: 1.08-5.86] (p = 0.033), and the adjusted OR of AI for ICI discontinuation due to irAE was 3.32 [1.41-7.78] (p = 0.006). Patients with pre-existing AI experienced a significantly shorter irAE-free survival time compared to those without AI (median irAE-free survival: 5.7 months [95% CI: 3.5-7.8] vs 10.4 months [95% CI: 7.9-12.9], respectively, p = 0.035). Frequently observed irAEs in full ICI cohort, such as dermatologic issues (7.5%), pneumonitis (7.1%), hepatitis (4.6%), and hypothyroidism (4.2%), were often accompanied by pre-existing AI. Furthermore, pre-existing AI flared up in 6 cases (37.5% in AI-positive irAE-positive cases). The activity of AI was not related to the occurrence of irAEs. Grade 3 or higher irAEs were observed in 6 out of 20 (30.0%) cases in AI-accompanied patients complicated with irAEs. Although having a complicated AI increases the risk of irAEs, it may not necessarily be a contraindication for ICI treatment if closely monitored. (292<300 characters).

Prognostic impact of soluble PD-L1 derived from tumor-associated macrophages in non-small-cell lung cancer.

Programmed cell death-ligand 1 (PD-L1) on tumor cells can be degraded to soluble form (sPD-L1) and enter circulation, however, the clinical significances of sPD-L1 in peripheral blood remains to be elucidated in non-small-cell lung cancer (NSCLC). We monitored plasma sPD-L1 levels during perioperative periods and evaluated PD-L1-positive cells in tumor tissues in patients with operable NSCLC. Then the correlation between preoperative plasma sPD-L1 levels and relapse-free survival (RFS) was analyzed retrospectively. In patients who underwent radical surgery (n = 61), plasma sPD-L1 levels (median; 63.5 pg/mL) significantly increased 1 month after surgery (72.2 pg/mL, P < 0.001). The combined score of PD-L1-positive cells including tumor cells and tumor-associated macrophages (TAMs) was significantly associated with preoperative plasma sPD-L1 levels. In patients with high levels of preoperative plasma sPD-L1, the probability of 5-year RFS was significantly poor for patients with low PD-L1 expression intensity of tumor cells (tcPD-L1) compared with those with high tcPD-L1 (33.3% vs. 87.5%, respectively, P = 0.016; 95% CI, 0.013-0.964). In former group, PD-L1-positive TAMs were markedly infiltrating compared with those from latter group (246.4 vs. 76.6 counts/mm2, respectively, P = 0.003). In NSCLC, plasma sPD-L1 can reflect the accumulation of PD-L1-posotive TAMs, not just PD-L1-positive tumor cells. In patients with high levels of preoperative plasma sPD-L1, the prognoses after surgery depends on which PD-L1-positive cells, tumor cells or TAMs, are the primary source of the sPD-L1. Thus, measuring both plasma sPD-L1 levels and PD-L1 expression status of tumor cells and TAMs is of benefit for assessment of postoperative prognosis in operable NSCLC.

Oncogenic epidermal growth factor receptor signal-induced histone deacetylation suppresses chemokine gene expression in human lung adenocarcinoma.

Epidermal growth factor receptor (EGFR)-mutated (mt) lung adenocarcinoma (LA) is refractory to immune checkpoint inhibitors (ICIs). However, the mechanisms have not been fully elucidated. CD8+ T cell infiltration was significantly lower in EGFR-mt than in EGFR-wild-type LA, which was associated with suppression of chemokine expression. Since this T cell-deserted tumor microenvironment may lead to the refractoriness of ICIs against EGFR-mt LA, we investigated the mechanism by focusing on the regulation of chemokine expression. The expression of C-X-C motif ligand (CXCL) 9, 10 and 11, which constitute a gene cluster on chromosome 4, was suppressed under EGFR signaling. The assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) revealed open chromatin peaks near this gene cluster following EGFR-tyrosine kinase inhibitor (TKI) treatment. The histone deacetylase (HDAC) inhibitor recovered the expression of CXCL9, 10 and 11 in EGFR-mt LA. Nuclear HDAC activity, as well as histone H3 deacetylation, were dependent on oncogenic EGFR signaling. Furthermore, the Cleavage Under Targets and Tagmentation (CUT & Tag) assay revealed a histone H3K27 acetylation peak at 15 kb upstream of CXCL11 after treatment with EGFR-TKI, which corresponded to one of the open chromatin peaks detected by ATAC-seq. The data suggest that EGFR-HDAC axis mediates silencing of the chemokine gene cluster through chromatin conformational change, which might be relevant to the ICI resistance by creating T cell-deserted tumor microenvironment. Targeting this axis may develop a new therapeutic strategy to overcome the ICI resistance of EGFR-mt LA.

Status and prognostic value of immunological biomarkers of breast cancer.

The immune response to cancer serves an important role in disease progression and patient prognosis. For triple-negative breast cancer showing aggressive behavior, immunotherapy has a good efficacy because of the potent immunogenicity of this type of cancer. However, the dominant subtype, luminal human epidermal growth factor receptor-2 (HER2)-negative breast cancer, is less immunogenic. To determine whether luminal HER2-negative cancer reacts to the anticancer immune response, the present study analyzed the status and prognostic value of the principal immunological biomarkers of breast cancer, including tumor-infiltrating lymphocytes (TILs), CD8+ T lymphocytes, the major histocompatibility complex and programmed cell death ligand-1 (PD-L1). The biomarkers were compared between patients with luminal HER2-negative breast cancer and those with immunogenic subtypes including triple-negative and HER2-overexpressed breast cancer. A total of 71 patients with primary breast cancer were classified into the immunogenic non-luminal (n=23) and less immunogenic luminal HER2-negative groups (n=48) based on immunogenicity. In the luminal HER2-negative group, compared with patients with low TIL levels, those with high TIL levels were at an advanced stage of cancer (P=0.024) and showed worse relapse-free survival (P=0.057); however, the remaining biomarkers exhibited no association with cancer progression or prognosis. In the non-luminal group, patients with high TIL levels showed significantly better RFS than those with low TIL levels (P=0.014). Compared with non-luminal patients negative for PD-L1, those positive for PD-L1 exhibited better overall survival (P=0.064). Notably, TIL status was found to exhibit contrasting prognostic predictions based on immunogenicity. In conclusion, TILs are a strong candidate for prognostic prediction in breast cancer, regardless of the subtype. PD-L1 is a potential candidate for prognostic prediction in immunogenic breast cancers, but not in the luminal HER2-negative subtype.

Blood vessel remodeling in the cerebral cortex induced by binge alcohol intake in mice.

Ethanol is toxic to the brain and causes various neurological disorders. Although ethanol can directly exert toxicity on neurons, it also acts on other cell types in the central nervous system. Blood vessel endothelial cells interact with, and are affected by blood ethanol. However, the effects of ethanol on the vascular structures of the brain have not been well documented. In this study, we examined the effects of binge levels of ethanol on brain vasculature. Immunostaining analysis indicated structural alterations of blood vessels in the cerebral cortex, which became more tortuous than those in the control mice after ethanol administration. The interaction between the blood vessels and astrocytes decreased, especially in the upper layers of the cerebral cortex. Messenger RNA expression analysis revealed a unique downregulation of Vegfa mRNA encoding vascular endothelial growth factor (VEGF)-A among VEGF, angiopoietin, endothelin family angiogenic and blood vessel remodeling factors. The expression of three proteoglycan core proteins, glypican-5, neurocan, and serglycin, was also altered after ethanol administration. Thus, binge levels of ethanol affect the expression of VEGF-A and blood vessel-supporting proteoglycans, resulting in changes in the vascular structure of the cerebral cortex. Supplementary Information: The online version contains supplementary material available at 10.1007/s43188-022-00164-y.

Factors Associated with Cancer-Related Pain Requiring High-Dose Opioid Use in Palliative Cancer Patients.

Background: There are no universal tools to predict the necessity of high-dose opioid use for cancer-related pain. Early recognition and interventions for intractable cancer pain could minimize the distress of palliative patients. Objective: We sought to identify the clinical factors associated with high-dose opioid use in advanced cancer patients to recognize palliative patients who would develop intractable cancer pain, as early as possible. Setting/Subjects: Among 385 in-hospital cancer patients from April 1, 2014 to July 31, 2019, who were referred to the palliative care team for cancer-related pain, clinical factors significantly correlated to high-dose opioid use were retrospectively analyzed. Measurements: We conducted a multiple logistic regression analysis to identify variables significantly related to high-dose opioid use (>120 mg/day oral morphine equivalent dose). Results: Independent factors of high-dose opioid use included younger age (odds ratio [OR] 0.965, 95% confidence interval [CI] 0.944-0.986, p = 0.001), respiratory cancers (OR 1.882, 95% CI 1.069-3.312, p < 0.001), and opioid switch (OR 2.869, 95% CI 1.497-5.497, p = 0.001). The percentage of correct classifications of the regression equation was 86.9%. Conclusions: Younger age, respiratory cancers, and opioid switch were related to high-dose opioid use. Our findings may help palliative caregivers to deal with intractable cancer pain in palliative patients, and thus relieve their distress.

Structure-based substrate specificity analysis of GH11 xylanase from Streptomyces olivaceoviridis E-86.

Although many xylanases have been studied, many of the characteristics of xylanases toward branches in xylan remain unclear. In this study, the substrate specificity of a GH11 xylanase from Streptomyces olivaceoviridis E-86 (SoXyn11B) was elucidated based on its three-dimensional structure. Subsite mapping suggests that SoXyn11B has seven subsites (four subsites on the - side and three subsites on the + side), and it is one longer than the GH10 xylanase from S. olivaceoviridis (SoXyn10A). SoXyn11B has no affinity for the subsites at either end of the scissile glycosidic bond, and the sugar-binding energy at subsite - 2 was the highest, followed by subsite + 2. These properties were very similar to those of SoXyn10A. In contrast, SoXyn11B produced different branched oligosaccharides from bagasse compared with those of SoXyn10A. These branched oligosaccharides were identified as O-ß-D-xylopyranosyl-(1→4)-[O-α-L-arabinofuranosyl-(1→3)]-O-ß-D-xylopyranosyl-(1→4)-ß-D-xylopyranosyl-(1→4)-ß-D-xylopyranose (Ara3Xyl4) and O-ß-D-xylopyranosyl-(1→4)-[O-4-O-methyl-α-D-glucuronopyranosyl-(l→2)]-ß-D-xylopyranosyl-(1→4)-ß-D-xylopyranosyl-(1→4)-ß-D-xylopyranose (MeGlcA3Xyl4) by nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESI-MS) and confirmed by crystal structure analysis of SoXyn11B in complex with these branched xylooligosaccharides. SoXyn11B has a ß-jerryroll fold structure, and the catalytic cleft is located on the inner ß-sheet of the fold. The ligand-binding structures revealed seven subsites of SoXyn11B. The 2- and 3-hydroxy groups of xylose at the subsites + 3, + 2, and - 3 face outwards, and an arabinose or a glucuronic acid side chain can be linked to these positions. These subsite structures appear to cause the limited substrate specificity of SoXyn11B for branched xylooligosaccharides. KEY POINTS: • Crystal structure of family 11 ß-xylanase from Streptomyces olivaceoviridis was determined. • Topology of substrate-binding cleft of family 11 ß-xylanase from Streptomyces olivaceoviridis was characterized. • Mode of action of family 11 ß-xylanase from Streptomyces olivaceoviridis for substitutions in xylan was elucidated.

Substrate Specificities of GH8, GH39, and GH52 ß-xylosidases from Bacillus halodurans C-125 Toward Substituted Xylooligosaccharides.

Substrate specificities of glycoside hydrolase families 8 (Rex), 39 (BhXyl39), and 52 (BhXyl52) ß-xylosidases from Bacillus halodurans C-125 were investigated. BhXyl39 hydrolyzed xylotriose most efficiently among the linear xylooligosaccharides. The activity decreased in the order of xylohexaose > xylopentaose > xylotetraose and it had little effect on xylobiose. In contrast, BhXyl52 hydrolyzed xylobiose and xylotriose most efficiently, and its activity decreased when the main chain became longer as follows: xylotetraose > xylopentaose > xylohexaose. Rex produced O-ß-D-xylopyranosyl-(1 → 4)-[O-α-L-arabinofuranosyl-(1 → 3)]-O-ß-D-xylopyranosyl-(1 → 4)-ß-D-xylopyranose (Ara2Xyl3) and O-ß-D-xylopyranosyl-(1 → 4)-[O-4-O-methyl-α-D-glucuronopyranosyl-(l → 2)]-ß-D-xylopyranosyl-(1 → 4)-ß-D-xylopyranose (MeGlcA2Xyl3), which lost a xylose residue from the reducing end of O-ß-D-xylopyranosyl-(1 → 4)-[O-α-L-arabinofuranosyl-(1 → 3)]-O-ß-D-xylopyranosyl-(1 → 4)-ß-D-xylopyranosyl-(1 → 4)-ß-D-xylopyranose (Ara3Xyl4) and O-ß-D-xylopyranosyl-(1 → 4)-[O-4-O-methyl-α-D-glucuronopyranosyl-(1 → 2)]-ß-D-xylopyranosyl-(1 → 4)-ß-D-xylopyranosyl-(1 → 4)-ß-D-xylopyranose (MeGlcA3Xyl4). It was considered that there is no space to accommodate side chains at subsite -1. BhXyl39 rapidly hydrolyzes the non-reducing-end xylose linkages of MeGlcA3Xyl4, while the arabinose branch does not significantly affect the enzyme activity because it degrades Ara3Xyl4 as rapidly as unmodified xylotetraose. The model structure suggested that BhXyl39 enhanced the activity for MeGlcA3Xyl4 by forming a hydrogen bond between glucuronic acid and Lys265. BhXyl52 did not hydrolyze Ara3Xyl4 and MeGlcA3Xyl4 because it has a narrow substrate binding pocket and 2- and 3-hydroxyl groups of xylose at subsite +1 hydrogen bond to the enzyme.

Epidermal growth factor promotes glioblastoma cell death under glucose deprivation via upregulation of xCT (SLC7A11).

The cystine/glutamate antiporter xCT (SLC7A11) is frequently overexpressed in many cancers, including glioblastoma. Cystine taken up by the cells via xCT is reduced to cysteine, which is used to synthesize glutathione for antioxidant cellular defense. However, overexpression of xCT causes cell death under glucose-limited conditions. We found that stimulation of glioblastoma cells with epidermal growth factor (EGF) induces the upregulation of xCT and promotes cell death under glucose deprivation. Treatment with the mTOR inhibitor Torin 1 suppressed the EGF-induced upregulation of xCT and cell death. EGF increased xCT mRNA levels, which was suppressed by Torin 1. The lysosome inhibitor bafilomycin A1 increased xCT protein levels in the absence of EGF or in the presence of EGF and Torin 1. Taken together, our study suggests that EGF promotes glioblastoma cell death under glucose-limited conditions via the upregulation of xCT at transcriptional and protein levels in an mTOR-dependent manner.

Biphasic prognostic significance of PD-L1 expression status in patients with early- and locally advanced-stage non-small cell lung cancer.

Programmed cell death-ligand 1 (PD-L1) expression on tumor cells is induced by interferon-gamma, suggesting the induction of an anti-tumor immune response. In turn, binding of PD-L1 to programmed cell death 1 (PD-1) triggers an immune checkpoint pathway that contributes to tumor growth. Though it remains to be elucidated, the clinical significance of PD-L1 expression might vary with tumor progression in non-small-cell lung cancer (NSCLC). Immunohistochemical analysis of PD-L1 was done in tumor specimens from patients who underwent radical surgery for stage I-IIIA NSCLC (n = 228). Tumor PD-L1 expression intensity was semi-quantitatively scored and its correlation with various clinicopathological features and postoperative relapse-free survival (RFS) was assessed relative to pathological stage. In stage I, postoperative RFS was significantly prolonged in patients with a high PD-L1 score compared with a low PD-L1 score, exhibiting 5-year relapse-free probabilities of 94.1% and 75.1%, respectively (P = 0.031). A multivariate analysis revealed that a high PD-L1 score was a prognostic factor of longer postoperative RFS (hazard ratio: 0.111, P = 0.033). Conversely, in stages II and IIIA, patients with a high PD-L1 score tended to suffer from postoperative tumor recurrence. In early-stage NSCLC, high tumor PD-L1 expression status represents a biomarker to predict good prognosis after radical surgery and may reflect the induction of an antitumor immune response. However, in locally advanced stage NSCLC, tumor PD-L1 expression status may reflect the execution of an immune checkpoint pathway and predicts the incidence of postoperative tumor recurrence.

Detection of neoantigen-reactive T cell clones based on the clonal expansion using next-generation sequencing of T cell receptor ß complementarity-determining region 3.

Development of mechanism-driven biomarkers for immune checkpoint inhibitors (ICIs) in cancer immunotherapy requires sensitive and efficacious assays to identify tumor antigen (Ag)-specific T cells. We demonstrated the concept for a sensitive method to determine Ag-reactive T cell clones based on clonal expansion using model neoantigens (NeoAgs) rather than cytokine production. Sequential increase in T cell clonal frequencies following Ag stimulation was detected by next generation sequencing (NGS) of T cell receptor ß (TCR ß) complementarity-determining region 3 (CDR3), with a higher sensitivity than that of enzyme-linked immunospot (ELISPOT) by 100-fold. The TCRß CDR3 sequences could represent useful markers to track dynamic changes during immunotherapy. The TCRß NGS-based method could represent a novel platform both for the development of new biomarkers as well as several therapeutic options.

Clinical significance of PD-L1-positive cancer-associated fibroblasts in pN0M0 non-small cell lung cancer.

OBJECTIVES: Cancer-associated fibroblasts (CAFs) are a dominant cell type in tumor stroma and support the generation of pro-tumorigenic microenvironment. CAFs have frequent opportunities to interact with immune cells infiltrating the tumor stroma, but the process remains to be determined. In this study, we focused on immune checkpoint mechanism. We also examined the induction of programmed cell death-ligand 1 (PD-L1) on CAFs by immune cell, and the clinical significance of PD-L1-expressed CAFs in non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: CAFs were isolated from human NSCLC tissues, and PD-L1 expression levels in CAFs were analyzed by real-time polymerase chain reaction and flow-cytometry. Following immunohistochemical analysis of PD-L1 in surgically resected pN0M0 NSCLC (n = 125, including 88 invasive adenocarcinomas and 37 squamous cell carcinomas), the correlation of PD-L1-positive CAFs with clinicopathological features was investigated. RESULTS: PD-L1 mRNA and protein expression on CAFs was upregulated by exogenously supplemented interferon-gamma (IFN-γ) and downregulated through the depletion of IFN-γ. PD-L1 expression on CAFs was upregulated by co-culture with activated lymphocytes releasing IFN-γ. Immunohistochemistry revealed that PD-L1-positive CAFs were observed in 31 cases (24.8%). Postoperative relapse-free survival was significantly prolonged in patients with PD-L1-positive CAFs as compared with those with PD-L1-negative CAFs, with 5-year relapse-free probabilities of 84.5% and 66.3%, respectively (P = 0.031). Multivariate analysis revealed that PD-L1 expression on CAFs was an independent prognostic factor of longer relapse-free survival after surgery (hazard ratio: 3.225, P = 0.027). CONCLUSION: PD-L1 expression on CAFs is reversibly regulated by environmental stimuli including IFN-γ from activated lymphocytes. In the non-metastatic NSCLC, PD-L1 expression on CAFs suggests the induction of anti-tumor immune responses, contributing to better prognosis after surgery.

The cystine/glutamate antiporter xCT is a key regulator of EphA2 S897 phosphorylation under glucose-limited conditions.

EphA2, which belongs to the Eph family of receptor tyrosine kinases, is overexpressed in a variety of human cancers. Serine 897 (S897) phosphorylation of EphA2 is known to promote cancer cell migration and proliferation in a ligand-independent manner. In this study, we show that glucose deprivation induces S897 phosphorylation of EphA2 in glioblastoma cells. The phosphorylation requires the activity of the cystine/glutamate antiporter xCT and reactive oxygen species (ROS)-dependent ERK and RSK activation. Furthermore, depletion of EphA2 in glioblastoma cells leads to decreased cell viability under glucose starvation. Our results suggest a role of EphA2 in glioblastoma cell viability under glucose-limited conditions.

Functional Characterization of the GH10 and GH11 Xylanases from Streptomyces olivaceoviridis E-86 Provide Insights into the Advantage of GH11 Xylanase in Catalyzing Biomass Degradation.

We functionally characterized the GH10 xylanase (SoXyn10A) and the GH11 xylanase (SoXyn11B) derived from the actinomycete Streptomyces olivaceoviridis E-86. Each enzyme exhibited differences in the produced reducing power upon degradation of xylan substrates. SoXyn10A produced higher reducing power than SoXyn11B. Gel filtration of the hydrolysates generated by both enzymes revealed that the original substrate was completely decomposed. Enzyme mixtures of SoXyn10A and SoXyn11B produced the same level of reducing power as SoXyn10A alone. These observations were in good agreement with the composition of the hydrolysis products. The hydrolysis products derived from the incubation of soluble birchwood xylan with a mixture of SoXyn10A and SoXyn11B produced the same products as SoXyn10A alone with similar compositions. Furthermore, the addition of SoXyn10A following SoXyn11B-mediated digestion of xylan produced the same products as SoXyn10A alone with similar compositions. Thus, it was hypothesized that SoXyn10A could degrade xylans to a smaller size than SoXyn11B. In contrast to the soluble xylans as the substrate, the produced reducing power generated by both enzymes was not significantly different when pretreated milled bagasses were used as substrates. Quantification of the pentose content in the milled bagasse residues after the enzyme digestions revealed that SoXyn11B hydrolyzed xylans in pretreated milled bagasses much more efficiently than SoXyn10A. These data suggested that the GH10 xylanases can degrade soluble xylans smaller than the GH11 xylanases. However, the GH11 xylanases may be more efficient at catalyzing xylan degradation in natural environments (e.g. biomass) where xylans interact with celluloses and lignins.

Hypoxia­induced galectin­3 enhances RhoA function to activate the motility of tumor cells in non­small cell lung cancer.

Galectin­3 plays crucial roles in tumor progression. However, in non­small cell lung cancer (NSCLC), it remains unclear whether the hypoxic tumor microenvironment enhances galectin­3­induced cell motility. We investigated galectin­3 expression in NSCLC cells under hypoxia, and the possible molecular mechanisms by which galectin­3 influences tumor aggressiveness. Galectin­3 levels in NSCLC cell lines under hypoxia were assessed using reverse transcription PCR and western blotting. To clarify the role of endogenous galectin­3, the effect of galectin­3 knockdown in NSCLC cells was investigated using scratch and invasion assays. The expression and clinicopathological significance of galectin­3 in 57 patients with pN0M0 invasive pulmonary adenocarcinoma were investigated by immunohistochemistry. Both mRNA and protein levels of galectin­3 in the NSCLC cell lines A549 and LK­2 were upregulated by hypoxia. As revealed by scratch and invasion assays, the cell migratory and invasive activities were significantly increased under hypoxia, but were reduced by galectin­3 knockdown. Notably, addition of galectin­3 to the media did not improve the cell motility impaired by galectin­3 knockdown. To clarify the role of endogenous galectin­3 in the enhancement of tumor cell motility under hypoxia, we focused on the function of RhoA. RhoA level in the plasma membrane, but not in the cytoplasm, was increased under hypoxia and decreased by galectin­3 knockdown. RhoA activity was significantly enhanced under hypoxia and effectively inhibited by galectin­3 knockdown. In patients with pN0M0 invasive pulmonary adenocarcinoma, higher galectin­3 expression on tumor cells was significantly associated with tumor cell invasion into microvessels and tumor recurrence after surgery. These data demonstrate that in NSCLC cells under hypoxia, upregulated galectin­3 levels increase the localization of RhoA to the plasma membrane, thus enhancing RhoA activity, which is associated with aggressive cell motility. In pN0M0 invasive pulmonary adenocarcinoma, galectin­3 is a potential biomarker for predicting tumor recurrence after radical surgery.

Blocking the FSTL1-DIP2A Axis Improves Anti-tumor Immunity.

Immune dysfunction is a strong factor in the resistance of cancer to treatment. Blocking immune checkpoint pathways is a promising approach to improve anti-tumor immunity, but the clinical efficacies are still limited. We previously identified follistatin-like 1 (FSTL1) as a determinant of immune dysfunction mediated by mesenchymal stromal/stem cells (MSCs) and immunoregulatory cells. Here, we demonstrate that blocking FSTL1 but not immune checkpoint pathways significantly suppresses cancer progression and metastasis in several mouse tumor models with increased MSCs. Expression of DIP2A (the receptor of FSTL1) in tumor cells is critical for FSTL1-induced immunoresistance. FSTL1/DIP2A co-positivity in tumor tissues correlates with poor prognosis in NSCLC patients. Thus, breaking the FSTL1-DIP2A axis may be a useful strategy for successfully inducing anti-tumor immunity.

The mechanism of de novo expression of programmed cell death-ligand 1 in squamous cell carcinoma of the lung.

Immune checkpoint mechanisms such as the programmed cell death-ligand 1-programmed cell death 1 (PD­L1-PD­1) axis are utilized by tumor cells to evade the cytotoxicity of effector immune cells. However, environmental factors responsible for the expression of PD­L1 on tumor cells remain to be fully elucidated. We hypothesized that an immunological interaction with tumor-infiltrating CD8+ lymphocytes (CD8+ TILs) would contribute to PD­L1 expression in tumor cells. To verify this hypothesis, we examined the effect of interferon-γ (IFN-γ), a cytokine secreted by CD8+ TILs, on PD­L1 expression in pulmonary squamous cell carcinomas in vitro. We also evaluated the expression of PD­L1 and major histocompatibility complex (MHC) class I molecules on tumor cells and CD8+ TILs in squamous cell carcinomas of the lung (n=77) by immunohistochemistry. IFN-γ upregulated PD­L1 expression on pulmonary squamous carcinoma cells, and the reaction was reversible. In cases where which MHC class I molecule-positive tumor cells were dominant (n=72, 93.5%), cases in which PD­L1-positive tumor cells were dominant (PD­L1+ tumor cell­dominant cases; n=45) were more frequently observed than PD­L1-negative tumor cell­dominant cases (n=27) (P=0.006). The number of CD8+ TILs was significantly higher in PD­L1+ tumor cell­dominant cases compared with PD­L1- tumor cell­dominant cases (P=0.005). These data suggest that the de novo expression of PD­L1 on tumor cells is upregulated by IFN-γ secreted from CD8+ TILs upon recognition of the tumor cells with an MHC class I molecule.

Quantitative analysis and clonal characterization of T-cell receptor ß repertoires in patients with advanced non-small cell lung cancer treated with cancer vaccine.

With the development of cancer immunotherapy that may activate T cells, a practical and quantitative method to improve monitoring and/or prediction of immunological response of patients as a predictive biomarker is of importance. To examine possible biomarkers for a therapeutic cancer vaccine containing a mixture of three epitope peptides derived from cell division-associated 1, lymphocyte antigen 6 complex locus K and insulin-like growth factor-II mRNA-binding protein 3, T-cell receptor ß (TCRß) repertoires of blood samples from 24 patients with human leukocyte antigen-A*2402-positive non-small cell lung cancer were characterized prior to and following 8 weeks of the cancer vaccine treatment, by applying a next-generation sequencing method. It was identified that 14 patients with overall survival (OS) times of ≥12 months had significantly lower TCRß diversity indexes in samples prior to treatment, compared with 10 patients who succumbed within 1 year (P=0.03). In addition, patients with a high level of activated CD8+ T cells that are defined by a high granzyme A/CD8 ratio had favorable OS rates (log-rank test, P=0.04). The TCRß diversity index and immunogenic gene markers following vaccine administration may serve as predictive or monitoring biomarkers for cancer vaccine treatment.

Clinical outcome of posterior fixation surgery in patients with vertebral metastasis of lung cancer.

Vertebral metastasis of non-small-cell lung cancer (NSCLC) often leads to neurological paralysis, with deterioration of the patients' activities of daily living (ADL). Surgical treatments for the symptoms are unlikely to be recommended due to the poor prognosis of patients with advanced NSCLC. The aim of the present study was to retrospectively evaluate the clinical outcome of posterior spinal fixation surgery in patients with neurological paralysis resulting from vertebral metastasis of NSCLC. Between April, 2007 and March, 2012, 4 patients (3 men and 1 woman; median age, 56.5 years) underwent fixation surgery at the Shiga University of Medical Science Hospital (Otsu, Japan). The mean preoperative Tokuhashi and Tomita scores of the patients were high (8.25 and 7.0, respectively). However, the Frankel grade functional score and performance status of the patients improved following fixation surgery, after which all patients received chemoradiotherapy. Postoperatively, the median paralysis-free time was 41 months (range, 17-42 months) and the median survival time was 42.5 months (range, 22-43 months). According to the functional scores, the patients had a poor prognosis, which may have been a contraindication for fixation surgery. In these cases, however, surgical treatment improved the patients' ADL and increased the likelihood of receiving anticancer therapy, contributing to the prolongation of survival. Therefore, fixation surgery may be beneficial for patients with neurological paralysis following vertebral metastasis of advanced NSCLC.