Targeting cancer-associated fibroblast autophagy renders pancreatic cancer eradicable with immunochemotherapy by inhibiting adaptive immune resistance

Accumulating evidence suggests that cancer-associated fibroblast (CAF) macroautophagy/autophagy is crucial in tumor development and may be a therapeutic target for pancreatic ductal adenocarcinoma (PDAC). However, the role of CAF autophagy during immune surveillance and cancer immunotherapy is unclear. The present study revealed that the inhibition of CAF autophagy suppresses in vivo tumor development in immune-deficient xenografts. This deletion compromises anti-tumor immunity and anti-tumor efficacy both in vitro and in vivo by upregulating CD274/PDL1 levels in an immune-competent mouse model. A block in CAF autophagy reduced the production of IL6 (interleukin 6), disrupting high desmoplastic TME and decreasing USP14 expression at the transcription level in pancreatic cancer cells. We further identify USP14 as the post-translational factor responsible for downregulating CD274 expression by removing K63 linked-ubiquitination at the K280 residue. Finally, chloroquine diphosphate-loaded mesenchymal stem cell (MSC)-liposomes, by accurately targeting CAFs, inhibited CAF autophagy, improving the efficacy of immunochemotherapy to combat pancreatic cancer.Abbreviation: AIR: adaptive immune resistance; ATRA: all-trans-retinoicacid; CAF: cancer-associated fibroblast; CD274/PDL1: CD274 molecule; CM: conditioned medium; CQ: chloroquine diphosphate; CyTOF: Mass cytometry; FGF2/bFGF: fibroblast growth factor 2; ICB: immune checkpoint blockade; IF: immunofluorescence; IHC: immunohistochemistry; IP: immunoprecipitation; MS: mass spectrometer; MSC: mesenchymal stem cell; PDAC: pancreatic ductal adenocarcinoma; TEM: transmission electron microscopy; TILs: tumor infiltrating lymphocytes; TME: tumor microenvironment; USP14: ubiquitin specific peptidase 14.

Expression pattern of PD-1/PD-L1 in primary liver cancer with clinical correlation

Immunotherapy, including ICIs, has emerged as an invaluable treatment option for advanced PLC. Nevertheless, the expression patterns of PD-L1 and PD-1 in PLC remain incompletely understood. In this study, the expression pattern and clinical correlation of PD-L1 and PD-1 were analysed in 5245 PLC patients. The positivity rates of PD-L1 and PD-1 were very low in the patient PLCs, but the positivity rates of PD-L1 and PD-1 were higher in the ICC and cHCC-ICC than in HCC. The expression of PD-L1 and PD-1 correlated with the malignant phenotypes and clinicopathological characteristics of PLC. Interestingly, PD-1 positivity might serve as an independent prognostic factor. Based on a systematic analysis of a large amount of PLC tissues, we proposed a novel classification of PD-1/PD-L1 expression in HCC and ICC. In light of this stratification, we observed a close correlation between PD-L1 levels and PD-1 expression in HCC and ICC.

On the Road towards Small-Molecule Programmed Cell Death 1 Ligand 1 Positron Emission Tomography Tracers: A Ligand-Based Drug Design Approach

PD-1/PD-L1 immune checkpoint blockade for cancer therapy showed promising results in clinical studies. Further endeavors are required to enhance patient stratification, as, at present, only a small portion of patients with PD-L1-positive tumors (as determined by PD-L1 targeted immunohistochemistry; IHC) benefit from anti-PD-1/PD-L1 immunotherapy. This can be explained by the heterogeneity of tumor lesions and the intrinsic limitation of multiple biopsies. Consequently, non-invasive in vivo quantification of PD-L1 on tumors and metastases throughout the entire body using positron emission tomography (PET) imaging holds the potential to augment patient stratification. Within the scope of this work, six new small molecules were synthesized by following a ligand-based drug design approach supported by computational docking utilizing lead structures based on the (2-methyl-[1,1'-biphenyl]-3-yl)methanol scaffold and evaluated in vitro for potential future use as PD-L1 PET tracers. The results demonstrated binding affinities in the nanomolar to micromolar range for lead structures and newly prepared molecules, respectively. Carbon-11 labeling was successfully and selectively established and optimized with very good radiochemical conversions of up to 57%. The obtained insights into the significance of polar intermolecular interactions, along with the successful radiosyntheses, could contribute substantially to the future development of small-molecule PD-L1 PET tracers.

PD-L1 Exon 3 Is a Hidden Switch of Its Expression and Function in Oral Cancer Cells

The interaction between programmed cell death 1 ligand 1 (PD-L1) and programmed cell death protein 1 (PD-1) protects tumor cells from immune surveillance. PD-L1 exon 3 is a potential alternative exon and encodes an Ig variable (IgV) domain. Here, we found that a lack of exon 3 leads to the significant loss of cellular membrane locations and the dramatically reduced protein expression of PD-L1, indicating that PD-L1 exon 3 is essential for its protein expression and translocation to the cell membrane. Notably, oral cancer cells show almost no exon 3 skipping to ensure the expression of the full-length, functional PD-L1 protein. We discovered two key exonic splicing enhancers (ESEs) for exon 3 inclusion. Two efficient antisense oligonucleotides (ASOs) were identified to block these two ESEs, which can significantly trigger exon 3 skipping and decrease the production of full-length, functional PD-L1 on the surface of cancer cells. Treatment of oral cancer cells with these ASOs significantly enhanced immune cells' suppression of cancer cell proliferation. Surprisingly, these two ASOs also significantly inhibited cell growth and induced cell pyroptosis in oral cancer cells. Altogether, the results of our study demonstrate the pivotal roles of exon 3 in PD-L1 expression and provide a novel anti-PD-L1 method.

Efficacy and safety of pembrolizumab monotherapy in patients with advanced thyroid cancer in the phase 2 KEYNOTE-158 study

BACKGROUND

The authors report results from the thyroid carcinoma cohort of the multicohort phase 2 KEYNOTE-158 study (NCT02628067), which evaluated pembrolizumab monotherapy in patients with previously treated cancers.

METHODS

Eligible patients had histologically and/or cytologically confirmed papillary or follicular thyroid carcinoma, failure of or intolerance to prior therapy, and measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. Patients received pembrolizumab (200 mg) every 3 weeks for up to 35 cycles. The primary end point was objective response rate (ORR) per RECIST v1.1 by independent central review.

RESULTS

A total of 103 patients were enrolled and received pembrolizumab. Median duration from first dose to data cutoff (October 5, 2020) was 49.4 (range, 43.9-54.9) months. ORR was 6.8% (95% confidence interval [CI], 2.8%-13.5%), and median duration of response was 18.4 (range, 4.2-47.2+) months. ORR was 8.7% (95% CI, 2.4%-20.8%) among patients with programmed cell death ligand 1 (PD-L1) combined positive score (CPS) ≥1 (n = 46) and 5.7% (95% CI, 1.2%-15.7%) among patients with PD-L1 CPS <1 (n = 53). Median overall survival and progression-free survival were 34.5 (95% CI, 21.2 to not reached) and 4.2 (95% CI, 3.9-6.2) months, respectively. Treatment-related adverse events occurred in 69.9% of patients (grade 3-5, 14.6%).

CONCLUSIONS

Pembrolizumab demonstrated manageable toxicity and durable antitumor activity in a small subset of patients with advanced thyroid cancer. These results provide evidence of modest antitumor activity in this setting regardless of tumor PD-L1 expression. Future studies evaluating immune checkpoint inhibitors in patients with differentiated thyroid cancer should focus on biomarker-driven patient selection or combination of immune checkpoint inhibitors with other agents, in order to achieve higher response rates than observed in this study.

Hepatic failure associated with immune checkpoint inhibitors: An analysis of the Food and Drug Administration Adverse Event Reporting System database

BACKGROUND

Hepatic failure induced by immune checkpoint inhibitors (ICIs) has been reported in only a few case series and case reports.

OBJECTIVE

We aimed to explore the association between ICIs and hepatic failure and characterize the clinical features of ICI-associated hepatic failure in the pharmacovigilance database.

METHODS

Data from the first quarter (Q1) of 2015 to the fourth quarter (Q4) of 2021 in the US Food and Drug Administration Adverse Event Reporting System (FAERS) database were retrieved for disproportionality and Bayesian analysis. Reporting odds ratios (ROR) and information component (IC) were used to evaluate correlations between ICIs and hepatic failure.

RESULTS

Hepatic failure occurred in 0.19% (18,454/9,647,655) of all cases in the FAERS database, of which 654 cases were associated with ICIs. The overall median time from ICIs initiation to hepatic failure onset was 38 days, 72.3% of the adverse events occurred within the first 3 months, and 68.65% of the cases died after developing hepatic failure. In general, a strong signal was shown between ICIs and hepatic failure (ROR₀₂₅  = 2.70, IC₀₂₅  = 1.39). For the three categories of ICIs, programmed cell death 1 ligand 1 inhibitors (ROR₀₂₅  = 3.09, IC₀₂₅  = 1.57) had a higher risk signal than programmed cell death protein 1 inhibitors and cytotoxic T lymphocyte-associated protein 4 inhibitors. For monotherapy, atezolizumab showed the strongest risk signal (ROR₀₂₅  = 4.07, IC₀₂₅  = 1.90). The combination of nivolumab and ipilimumab showed stronger signals of hepatic failure compared with nivolumab or ipilimumab alone (nivolumab + ipilimumab vs. ipilimumab: ROR₀₂₅  = 1.40, IC₀₂₅  = 0.16; nivolumab + ipilimumab vs. nivolumab: ROR₀₂₅  = 1.24, IC₀₂₅  = 0.34). Considering the concomitant agents used with ICIs, the majority of these regimens showed stronger signals than ICI monotherapy, such as acetaminophen (ICIs + acetaminophen vs. ICIs: ROR₀₂₅  = 1.06, IC₀₂₅  = 0.32).

CONCLUSIONS

ICIs had possible strong signals associated with hepatic failure, and most cases of hepatic failure occurred within the first 3 months and had poor outcomes, which should attract clinical attention.

Protective effects of blocking PD-1 pathway on retinal ganglion cells in a mouse model of chronic ocular hypertension

Purpose

In this study, we aimed to investigate whether Programmed cell death 1 ligand 1/programmed cell death 1 ligand 2 (PD-L1/PD-L2) double knockout (dKO) has a protective effect on RGCs in a mouse model of chronic ocular hypertension (COHT).

Methods

We used superparamagnetic iron oxide to induce COHT in mice. Apoptosis of retinal ganglion cells (RGCs) and activation of microglia were evaluated using western blotting (WB) and immunofluorescence staining of the mouse retina. In addition, we also conducted transcriptome sequencing and further gene expression analyses using the gene ontology (GO) and Kyoto Encyclopedia of Genes (KEGG) database.

Results

In the mouse model of COHT, PD-L1/PD-L2 prevented the apoptosis of RGCs to some extent. Blocking the programmed cell death 1 (PD-1) pathway also increased the number of anti-inflammatory M2-activated microglia and enhanced the phosphorylation of its related pathway signal transducer and activator of transcription (STAT)6. Sequencing results showed that this protective effect may have been achieved by regulating the NF-B, tumour necrosis factor (TNF), PI3K/Akt and toll-like receptor signaling pathway etc.

Conclusion

Blocking the PD-1 pathway has a protective effect on RGCs in the mouse model of COHT induced by superparamagnetic iron oxide.

What does radiomics do in PD-L1 blockade therapy of NSCLC patients?

With the in‐depth understanding of programmed cell death 1 ligand 1 (PD‐L1) in non‐small cell lung cancer (NSCLC), PD‐L1 has become a vital immunotherapy target and a significant biomarker. The clinical utility of detecting PD‐L1 by immunohistochemistry or next‐generation sequencing has been written into guidelines. However, the application of these methods is limited in some circumstances where the biopsy size is small or not accessible, or a dynamic monitor is needed. Radiomics can noninvasively, in real‐time, and quantitatively analyze medical images to reflect deeper information about diseases. Since radiomics was proposed in 2012, it has been widely used in disease diagnosis and differential diagnosis, tumor staging and grading, gene and protein phenotype prediction, treatment plan decision‐making, efficacy evaluation, and prognosis prediction. To explore the feasibility of the clinical application of radiomics in predicting PD‐L1 expression, immunotherapy response, and long‐term prognosis, we comprehensively reviewed and summarized recently published works in NSCLC. In conclusion, radiomics is expected to be a companion to the whole immunotherapy process.

Inhibition of PI3Kδ Differentially Regulates Poly I:C- and Human Metapneumovirus-Induced PD-L1 and PD-L2 Expression in Human Bronchial Epithelial Cells

Bronchial epithelial cells are front sentinels eliciting innate and adaptive immunity to respiratory viral pathogens. Recognition of viral double-stranded RNA induces antiviral interferon (IFN) responses in bronchial epithelial cells. Co-inhibitory molecules programmed cell death 1 ligand 1 (PD-L1) and ligand 2 (PD-L2) were also induced on bronchial epithelial cells, which bind programmed cell death 1 on T cell and inhibit the function of virus-specific cytotoxic T lymphocyte. A previous study showed that antiviral type I IFN increased PD-L1 and PD-L2 expression in cultured melanoma cells. However, it remains unknown whether antiviral IFNs affect PD-L1 and PD-L2 expression in bronchial epithelial cells. In addition, we previously reported that inhibition of PI3Kδ signaling enhanced antiviral IFN responses in human primary bronchial epithelial cells (PBECs). Here we assessed the effect of exogenous IFNs or a selective PI3Kδ inhibitor IC87114 on PD-L1 and PD-L2 in PBECs stimulated with a synthetic double-stranded RNA poly I:C or human metapneumovirus. Treatment with IFNβ or IFNλ increased PD-L1 and PD-L2, and IFNβ or IFNλ treatment plus poly I:C further increased both expressions. Treatment with IC87114 or transfection with siRNA targeting PI3K p110δ enhanced poly I:C–induced gene and protein expression of PD-L2, whereas IC87114 suppressed poly I:C–induced PD-L1. IC87114 enhanced poly I:C–induced gene expression of IFNβ, IFNλ, and IFN-regulated genes via increased TBK1 and IRF3 phosphorylation. Transfection with siIRF3 counteracted the enhancement of poly I:C–induced PD-L2 by IC87114, whereas IC87114 suppressed poly I:C–induced PD-L1 regardless of transfection with siNC or siIRF3. Similar effects of IC87114 on PD-L1 and PD-L2 expression were observed in human metapneumovirus–infected PBECs. We showed for the first time that type I and type III IFNs induced the expression of PD-L1 and PD-L2 in PBECs. Our findings suggest that during viral infections, inhibition of PI3Kδ differentially regulates PD-L1 and PD-L2 expression in bronchial epithelial cells.

Immune Checkpoint Inhibitor-Associated Tumor Lysis Syndrome: A Real-World Pharmacovigilance Study

Introduction: Immune checkpoint inhibitors (ICIs) have substantially improved the clinical outcomes of various malignancies. However, the adverse event of tumor lysis syndrome (TLS) has not been included in the National Comprehensive Cancer Network guidelines or drug inserts. In this study, we aimed to establish the relationship between ICI therapies and TLS events using data from a real-world pharmacovigilance database.

Methods: The MedDRA terms of TLS and both generic and brand names of ICIs were retrieved from the FDA Adverse Event Reporting System. Four frequentist algorithms were employed to confirm the association between the TLS and the ICI regimens, involving anti-cytotoxic T lymphocyte antigen-4 (anti-CTLA-4), anti–programmed death receptor-1 (PD-1)/programmed cell death 1 ligand 1 (PD-L1), and anti-(CTLA-4 + PD-1). A descriptive and statistical analysis was performed according to the case information.

Results: One hundred sixty-four TLS cases, where patients underwent anti-CTLA-4 (n = 14), anti-(PD-1)/(PD-L1) (n = 113), or anti-(CTLA-4 + PD-1) (n = 37) therapies, were collected between the first quarter of 2004 and the fourth quarter of 2020. The most coverage-reporting year, age-group, sex, reporter, region, country, and indication were 2020 (n = 62), 60–74 years (n = 65), males (n = 105), physician (n = 66), Asia (n = 80), Japan (n = 67), and lung and thymus malignancies (n = 40), respectively. The median TLS onset time associated with anti-CTLA-4, anti-(PD-1)/(PD-L1), and anti-(CTLA-4 + PD-1) therapies was 6 (IQR: 2–39.5), 9 (IQR: 2–40), and 20 (IQR: 7.5–37.75) days, respectively. Mortality distribution of 71 reported death outcomes among three groups was statistically significant. All four algorithm signal values of anti-(CTLA-4 + PD-1) were higher than those of anti-CTLA-4 and anti-(PD-1)/(PD-L1).

Conclusion: Elderly male patients with lung and thymus malignancies are frequently predisposed to TLS. ICI therapies could induce TLS in both solid and hematological malignancies. The rapid onset time and poor outcomes of patients prompt caution from health-care professionals.

Targeting PD-L1 (Programmed death-ligand 1) and inhibiting the expression of IGF2BP2 (Insulin-like growth factor 2 mRNA-binding protein 2) affect the proliferation and apoptosis of hypopharyngeal carcinoma cells

Programmed cell death-ligand 1 (PD-L1) have been attracting increasing attention in cancer diagnosis and treatment. The insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) is involved in the progression of multiple types of cancer. So, the role of IGF2BP2 and PD-L1 in hypopharyngeal carcinoma was assessed. Western blotting and immunochemistry were used to evaluate the expression of IGF2BP2 and PD-1/PD-L1. IGF2BP2 expression was knocked down in FaDu cells, and the effects on cell viability, apoptosis and proliferation were measured. A tumor-bearing nude model of hypopharyngeal carcinoma was constructed to evaluate the effect of a PD-L1 inhibitor and IGF2BP2 knockdown on hypopharyngeal carcinoma in vivo. RNA pull-down assays were used to assess the interaction between IGF2BP2 and PD-L1. The results showed that knockdown of IGF2BP2 inhibited FaDu cell proliferation and promoted apoptosis, as evidenced by the lower cell viability, a higher ratio of TUNEL-positive cells, decreased expression of Bcl-2 and cyclins, and increased expression of cleaved-caspase 3. In vivo, the tumor volume and weight were reduced by both the PD-L1 inhibitor and IGF2BP2 knockdown. Additionally, the interaction between PD-L1 and IGF2BP2 was confirmed. In conclusion, the results in the present study revealed that inhibition of IGF2BP2 might be a potentially relevant method for treating hypopharyngeal carcinoma, and the effects might be mediated via inhibition of the PD-1/PD-L1 axis.

Diagnostic utility of programmed cell death ligand 1 (clone SP142) immunohistochemistry for malignant lymphoma and lymphoproliferative disorders: A brief review

The programmed cell death 1 (PD1)/PD1 ligand (PD-L1) axis plays an important role in tumor cell escape from immune control and has been most extensively investigated for therapeutic purposes. However, PD-L1 immunohistochemistry is still not used widely for diagnosis. We review the diagnostic utility of PD-L1 (by clone SP142) immunohistochemistry in large-cell lymphomas, mainly consisting of classic Hodgkin lymphoma (CHL) and diffuse large B-cell lymphoma (DLBCL). Neoplastic PD-L1 (nPD-L1) expression on Hodgkin and Reed-Sternberg cells is well-established among prototypic CHL. Of note, EBV+ CHL often poses a challenge for differential diagnosis from peripheral T-cell lymphoma with EBV+ non-malignant large B-cells; their distinction is based on the lack of PD-L1 expression on large B-cells in the latter. The nPD-L1 expression further provides a good diagnostic consensus for CHL with primary extranodal disease conceivably characterized by a combined pathogenesis of immune escape of tumor cells and immunodeficiency. Compared with CHL, the nPD-L1 expression rate is much lower in DLBCL, highlighting some specific subgroups of intravascular large B-cell lymphoma, primary mediastinal large B-cell lymphoma, and EBV+ DLBCL. They consist of nPD-L1-positive and -negative subgroups, but their clinicopathological significance remains to be elucidated. Microenvironmental PD-L1 positivity on immune cells may be associated with a favorable prognosis in extranodal DLBCL. PD-L1 (by SP142) immunohistochemistry has helped us to understand the immune biology of lymphoid neoplasms possibly related by immune escape and/or immunodeficiency. However, knowledge of these issues remains limited and should be clarified for diagnostic consensus in the future.

Effects of transarterial chemoembolization on the immunological function of patients with hepatocellular carcinoma

The present study aimed to investigate the effects of transarterial chemoembolization (TACE) on the immune function of patients with hepatocellular carcinoma (HCC). A total of 114 patients with HCC were selected and their peripheral blood was collected before and 1 month after TACE treatment. Flow cytometry and reverse transcription-quantitative PCR were performed to analyze the changes in immune function in patients before and after treatment. Kaplan-Meier curves were plotted for survival analysis. The programmed cell death ligand 1 (PD-L1) and programmed cell death protein 1 (PD1) expression before TACE treatment were significantly higher in patients with poor TACE response compared with those patients with well response. Higher PD-L1 mRNA expression in the peripheral blood mononuclear cells after TACE predicted a superior prognosis. After TACE treatment, the proportion of CD4⁺/CD8⁺ cells were decreased while the expression levels of programmed cell death protein 1 (PD1) were significantly increased. To conclude, TACE could reduce the proportion of CD4⁺/CD8⁺ cells and improve the mRNA expression levels of PD1 in patients with HCC. The expression levels of PD1 and PD-L1 were closely related to the therapeutic effect of TACE and the prognosis of patients with HCC. TACE combined with immunotherapy may have potential clinical value for patients with HCC.

Integration of comprehensive genomic profiling, tumor mutational burden, and PD-L1 expression to identify novel biomarkers of immunotherapy in non-small cell lung cancer

OBJECTIVES

This study aimed to explore the novel biomarkers for immune checkpoint inhibitor (ICI) responses in non-small cell lung cancer (NSCLC) by integrating genomic profiling, tumor mutational burden (TMB), and expression of programmed death receptor 1 ligand (PD-L1).

MATERIALS AND METHODS

Tumor and blood samples from 637 Chinese patients with NSCLC were collected for targeted panel sequencing. Genomic alterations, including single nucleotide variations, insertions/deletions, copy number variations, and gene rearrangements, were assessed and TMB was computed. TMB-high (TMB-H) was defined as ≥10 mutations/Mb. PD-L1 positivity was defined as ≥1% tumor cells with membranous staining. Genomic data and ICI outcomes of 240 patients with NSCLC were derived from cBioPortal.

RESULTS

EGFR-sensitizing mutations, ALK, RET, and ROS1 rearrangements were associated with lower TMB and PD-L1+/TMB-H proportions, whereas KRAS, ALK, RET, and ROS1 substitutions/indels correlated with higher TMB and PD-L1+/TMB-H proportions than wild-type genotypes. Histone-lysine N-methyltransferase 2 (KMT2) family members (KMT2A, KMT2C, and KMT2D) were frequently mutated in NSCLC tumors, and these mutations were associated with higher TMB and PD-L1 expression, as well as higher PD-L1+/TMB-H proportions. Specifically, patients with KMT2C mutations had higher TMB and PD-L1+/TMB-H proportions than wild-type patients. The median progression-free survival (PFS) was 5.47 months (95% CI 2.5-NA) in patients with KMT2C mutations versus 3.17 months (95% CI 2.6-4.27) in wild-type patients (p = 0.058). Furthermore, in patients with NSCLC who underwent ICI treatment, patients with TP53/KMT2C co-mutations had significantly longer PFS and greater durable clinical benefit (HR: 0.48, 95% CI: 0.24-0.94, p = 0.033). TP53 mutation combined with KMT2C or KRAS mutation was a better biomarker with expanded population benefit from ICIs therapy and increased the predictive power (HR: 0.46, 95% CI: 0.26-0.81, p = 0.007).

CONCLUSION

We found that tumors with different alterations in actionable target genes had variable expression of PD-L1 and TMB in NSCLC. TP53/KMT2C co-mutation might serve as a predictive biomarker for ICI responses in NSCLC.

IMPLICATIONS FOR PRACTICE

Cancer immunotherapies, especially immune checkpoint inhibitors (ICIs), have revolutionized the treatment of non-small cell lung cancer (NSCLC); however, only a proportion of patients derive durable responses to this treatment. Biomarkers with greater accuracy are highly needed. In total, 637 Chinese patients with NSCLC were analyzed using next-generation sequencing and IHC to characterize the unique features of genomic alterations and TMB and PD-L1 expression. Our study demonstrated that KMT2C/TP53 co-mutation might be an accurate, cost-effective, and reliable biomarker to predict responses to PD-1 blockade therapy in NSCLC patients and that adding KRAS to the biomarker combination creates a more robust parameter to identify the best responders to ICI therapy.

FGD5‑AS1 promotes cisplatin resistance of human lung adenocarcinoma cell via the miR‑142‑5p/PD‑L1 axis

Previous studies have reported that long non-coding (lnc) RNA FGD5-antisense 1 (FGD5-AS1) promotes tumor proliferation, migration and invasion. Therefore, the present study aimed to elucidate the biological role and underlying molecular mechanisms of FGD5-AS1 in cisplatin (DDP) resistance of lung adenocarcinoma (LAD) cells. The results demonstrated that FGD5-AS1 was highly expressed in DDP-resistant LAD tissues and cells. Knockdown of FGD5-AS1 decreased the proliferative, migratory and invasive abilities of DDP-resistant LAD cells. Moreover, it was identified that FGD5-AS1 acted as a molecular sponge for microRNA (miR)-142, and FGD5-AS1 enhanced the resistance of A549/DDP cells to DDP by directly interacting with miR-142. Programmed cell death 1 ligand 1 (PD-L1) was also found to be a key effector of the FGD5-AS1/miR-142 axis to regulate the chemoresistance of DDP-resistant LAD cells. In conclusion, the present study demonstrated that FGD5-AS1 increased DDP resistance of LAD via the miR-142/PD-L1 axis, which may offer a novel treatment strategy for patients with DDP-resistant LAD.

MicroRNA-200b is a potential biomarker of the expression of PD-L1 in patients with lung cancer

BACKGROUND

Advanced non-small cell lung cancer (NSCLC) has a high mortality rate and poor prognosis. However, outcomes have gradually improved after the introduction of novel immunotherapies, including immune checkpoint inhibitors (ICIs). Although programmed death-ligand 1 (PD-L1) expression in tumor tissues is a known biomarker for guiding ICI treatment of NSCLC, challenges such as difficulty of liquid biopsy and heterogeneous results during treatment persist. This study evaluated the potential of miR200b as a surrogate biomarker for PD-L1 expression.

METHODS

We used the human lung cancer cell lines H226, H460, H520, A549, and H1975. miR200b expression in blood and bronchoscopy specimens of NSCLC patients was evaluated using reverse-transcription-quantitative PCR. Using flow cytometry, PD-L1 expression in vitro, as well as in tumor tissues, was evaluated after transfection with a mimic miR200b or siRNA.

RESULTS

miR200b expression negatively correlated with PD-L1 expression in all cell lines. The induction or knockdown of miR200b also altered PD-L1 expression in vitro. The patient group with a PD-L1 tumor proportion score ≥ 50% had significantly lower miR200b expression in the bronchoscopy specimens (P = 0.025) and serum-derived exosomes (P = 0.022) than that with PD-L1 tumor proportion score < 50%.

CONCLUSIONS

miR200b can regulate PD-L1 expression in lung cancer cells, and miR200b expression in clinical specimens negatively correlated with PD-L1 expression. Thus, miR200b may be a useful surrogate biomarker for PD-L1 expression in lung cancer patients.

KEY POINTS

SIGNIFICANT FINDINGS OF THE STUDY: High PD-L1 expression was linked to low miR200b expression, whereas low PD-L1 expression was linked to high miR200b expression in human lung cancer patients. Thus, miR200b overexpression or silencing can control PD-L1 expression in cancer cells. What this study adds We demonstrated the potential of miR200b as a surrogate biomarker for PD-L1 expression in lung cancer patients.

GC-Derived EVs Enriched with MicroRNA-675-3p Contribute to the MAPK/PD-L1-Mediated Tumor Immune Escape by Targeting CXXC4

MicroRNAs (miRNAs) delivered by gastric cancer (GC)-secreted extracellular vesicles (GC-EVs) are associated with the immune escape in GC. Microarray analysis based on the GEO: GSE112369 dataset identified the presence of poorly expressed CXXC finger protein 4 (CXXC4) in GC, which was validated in clinical samples of GC patients. Moreover, prediction based on TargetScan analysis demonstrated the putative miR-675-3p binding site in the 3′ UTR region of CXXC4. Thereby, our study aims to determine the role of GC-EV-encapsulated miR-675-3p in GC. First, CXXC4 was found to be negatively correlated with programmed cell death 1 ligand 1 (PD-L1). The effects of mitogen-activated protein kinase (MAPK) signaling on GC were evaluated using activator of the MAPK pathway. The overexpression of CXXC4 led to a downregulated MAPK signaling pathway, thus decreasing PD-L1 expression to augment the proliferation and activation of T cells co-cultured with GC HGC-27 cells. GC-EV-encapsulated miR-675-3p negatively regulated the expression of its target gene CXXC4. GC-EV-encapsulated miR-675-3p increased PD-L1 expression to stimulate the immune escape in vitro and EV-encapsulated miR-675-3p accelerated cisplatin resistance in vivo. Collectively, the aforementioned findings present a mechanism in which EV-mediated miR-675-3p upregulates PD-L1 expression, promoting immune escape in GC.

PD-L1 Expression and a High Tumor Infiltrate of CD8+ Lymphocytes Predict Outcome in Patients with Oropharyngeal Squamous Cells Carcinoma

Carcinogenesis of human papillomavirus (HPV)-related (+) oropharyngeal squamous cell carcinoma (OPSCC) differs from HPV-negative (–) OPSCC. HPV-related immune-escape-mechanism could be responsible for the development and progression of HPV+ tumors and an immunophenotype different from HPV– OPSCC is expected. The purpose of this study was to analyze the expression of programmed cell death protein 1 ligand 1 (PD-L1) and its prognostic relevance in relation to CD8+ tumor infiltrating lymphocytes (TILs) and the major histocompatibility complex (MHC) I expression in OPSCC. We quantified PD-L1 expression on tumor cells (TC) and macrophages and MHC I expression in association to CD8⁺ TILs by immunohistochemistry on tissue microarray derived from 171 HPV+/-OPSCC. HPV-status was determined by p16^INK4a immunohistochemistry/HPV-DNA detection. Presence of CD8⁺ TILs, PD-L1 expression on TC, and a more frequent loss of MHC I in HPV+ compared to HPV- OPSCC was detected. A high amount of CD8⁺ TILs in the whole cohort and in HPV+ OPSCC and PD-L1 expression on TC in HPV- OPSCC was associated with favorable overall survival. There was a trend for an improved outcome according to PD-L1 expression (macrophages) in HPV+ OPSCC without reaching statistical significance. CD8⁺ TILs and PD-L1-expression have prognostic impact in OPSCC and might present useful biomarkers for predicting clinical outcome and personalized therapy concepts.

Combination of pembrolizumab and 125I attenuates the aggressiveness of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-associated mortality. Therapies targeting programmed cell death 1 ligand 1 (PD1L1) have promising effects on NSCLC. However, resistance to targeted therapy has become the main problem and the underling molecular mechanism remains unclear. In the present study, the expression of PD1L1 in NSCLC was determined and the association with clinicopathological characteristics was analyzed. A combination therapy was also constructed, including pembrolizumab (Pem) and iodine-125 (¹²⁵I), which represented an efficient strategy for the treatment of NSCLC. The expression of PD1L1 was upregulated in NSCLC tissues and positively correlated with the Ki-67 index, pathological subtypes and risk stages. A higher level of PD1L1 expression was associated with poorer survival in patients with NSCLC, which could be used as a prognostic indicator. When NSCLC cells were cultured in the presence of Pem and ¹²⁵I seeds, the combination treatment significantly abrogated the tumor proliferation and aggressiveness through the inhibition of matrix metalloproteinase-2 and -9 secretion. Flow cytometry analysis revealed pembrolizumab combined with ¹²⁵I contributed to a higher rate of apoptosis and cell cycle arrest, indicating that the combination treatment improved the resistance to immunotherapy. Furthermore, the associated molecular mechanism was the dysregulation of ADAM metallopeptidase domain 17. The findings from the present study revealed that PD1L1 could be used as a predictive biomarker, and the application of combination treatment of pembrolizumab and ¹²⁵I showed promising effects on NSCLC.

Age-related EBV-associated B-cell lymphoproliferative disorders and other EBV + lymphoproliferative diseases: New insights into immune escape and immunodeficiency through staining with anti-PD-L1 antibody clone SP142

Epstein-Barr virus (EBV) is prevalent among healthy individuals, and is implicated in numerous reactive and neoplastic processes in the immune system. The authors originally identified a series of senile or age-related EBV-associated B-cell lymphoproliferative disorders (LPD) bearing a resemblance to immunodeficiency-associated ones. These LPDs may be associated with immune senescence and are now incorporated into the revised 4th edition of 2017 WHO lymphoma classification as EBV-positive (EBV+) diffuse large B-cell lymphoma (DLBCL), not otherwise specified (NOS). These EBV+ B-cells often have a Hodgkin/Reed-Sternberg (HRS)-like appearance and are shared beyond the diagnostic categories of mature B-cell neoplasms, mature T-cell neoplasms, classic Hodgkin lymphoma, and immunodeficiency-associated LPD. In addition, peculiar new diseases, such as EBV+ mucocutaneous ulcer and EBV+ DLBCL affecting the young, were recognized. On the other hand, lymphoma classification is now evolving in accord with deeper understanding of the biology of programmed death ligand 1 (PD-L1). Assessing PD-L1 positivity by staining with the anti-PD-L1 monoclonal antibody SP142 provides new insight by discriminating between immune evasion and senescence or immunodeficiency. The aim of the present review is to briefly summarize the diagnostic use of immunostaining with SP142 in malignant lymphomas and/or LPDs that feature tumor and nonmalignant large B-cells harboring EBV.

Induction of PD-L1 by Nitric Oxide via JNK Activation in A172 Glioblastoma Cells

Glioblastoma comprises 54% of all the gliomas derived from glial cells and are lethally malignant tumors of the central nervous system (CNS). Glioma cells disrupt the blood-brain barrier, leading to access of circulating immune cells to the CNS. Blocking the interaction between programmed cell death 1 (PD-1) and programmed cell death 1 ligand 1 (PD-L1) enhances T-cell responses against tumor cells, and inhibition of the PD-1/PD-L1 pathway is used as immunotherapy for cancer, including glioblastoma. Nitric oxide (NO) has multiple physiological roles, such as immune modulation and neural transmission in the CNS. Moreover, it has both tumor-promoting and tumor-suppressive functions. We examined the effects of NOC-18, an NO donor, on the expression of PD-L1 in A172 glioblastoma cells. NOC-18 increased PD-L1 expression in A172 glioblastoma cells. Moreover, this increase is regulated via the c-Jun N-terminal kinase pathway.

Targeted therapy and immunotherapy: Emerging biomarkers in metastatic melanoma

Targeted therapy directed against oncogenic BRAF mutations and immune checkpoint inhibitors have transformed melanoma therapy over the past decade and prominently improved patient outcomes. However, not all patients will respond to targeted therapy or immunotherapy and many relapse after initially responding to treatment. This unmet need presents two major challenges. First, can we elucidate novel oncogenic drivers to provide new therapeutic targets? Second, can we identify patients who are most likely to respond to current therapeutic strategies in order to both more accurately select populations and avoid undue drug exposure in patients unlikely to respond? In an effort to evaluate the current state of the field with respect to these questions, we provide an overview of some common oncogenic mutations in patients with metastatic melanoma and ongoing efforts to therapeutically target these populations, as well as a discussion of biomarkers for response to immune checkpoint inhibitors-including tumor programmed death ligand 1 expression and the future use of neoantigens as a means of truly personalized therapy. This information is becoming important in treatment decision making and provides the framework for a treatment algorithm based on the current landscape in metastatic melanoma.

Characteristics of Tumor-Infiltrating Lymphocytes Prior to and During Immune Checkpoint Inhibitor Therapy

The tumor immune contexture plays a major role for the clinical outcome of patients. High densities of CD45RO⁺ T helper 1 cells and CD8⁺ T cells are associated with improved survival of patients with various cancer entities. In contrast, a higher frequency of tumor-infiltrating M2 macrophages is correlated with poor prognosis. Recent studies provide evidence that the tumor immune architecture also essentially contributes to the clinical efficacy of immune checkpoint inhibitor (CPI) therapy in patients. Pretreatment melanoma samples from patients who experienced a clinical response to anti-programmed cell death protein 1 (PD-1) treatment show higher densities of infiltrating CD8⁺ T cells compared to samples from patients that progressed during therapy. Anti-PD-1 therapy results in an increased density of tumor-infiltrating T lymphocytes in treatment responders. In addition, elevated frequencies of melanoma-infiltrating TCF7⁺CD8⁺ T cells are correlated with beneficial clinical outcome of anti-PD-1-treated patients. In contrast, a high density of tumor-infiltrating, dysfunctional PD-1⁺CD38^hi CD8⁺ cells in melanoma patients is associated with anti-PD-1 resistance. Such findings indicate that comprehensive tumor immune contexture profiling prior to and during CPI therapy may lead to the identification of underlying mechanisms for treatment response or resistance, and the design of improved immunotherapeutic strategies. Here, we focus on studies exploring the impact of intratumoral T and B cells at baseline on the clinical outcome of CPI-treated cancer patients. In addition, recent findings demonstrating the influence of CPIs on tumor-infiltrating lymphocytes are summarized.

Role and mechanism of programmed death-ligand 1 in hypoxia-induced liver cancer immune escape

Immune escape plays a vital role in the development of liver cancer. The interaction between programmed death-ligand 1 (PD-L1) and programmed cell death-1 is a key mediator of cancer immune escape, which leads to the suppression of anticancer immunity and promotion of tumor progression. Hypoxia is a common phenomenon in the tumor microenvironment. Under hypoxic conditions, suppressive immune cells, such as regulatory T cells, myeloid-derived suppressor cells and M2 macrophages, are frequently recruited to tumor tissues to form the immunosuppressive microenvironment in liver cancer. These cells secrete cancer-promoting inflammatory cytokines, which activate the STAT3 and NF-κB signaling pathways. Recent studies have shown that STAT3 is associated with NF-κB and that these transcription factors are often co-activated to regulate tumor proliferation, survival, angiogenesis and invasion. The activation of STAT3 and NF-κB signaling pathways can directly and indirectly induce PD-L1 expression. Therefore, further understanding of the association between hypoxia and PD-L1 may help in the future treatment of liver cancer. The present review summarizes the recent progresses on PD-L1-mediated regulation and facilitation of liver cancer cell immune escape in response to hypoxia.

The Evolving Landscape of Biomarkers for Anti-PD-1 or Anti-PD-L1 Therapy

The administration of antibodies blocking the immune checkpoint molecules programmed cell death protein 1 (PD-1) or programmed cell death 1 ligand 1 (PD-L1) has evolved as a very promising treatment option for cancer patients. PD-1/PD-L1 inhibition has significantly enhanced expansion, cytokine secretion, and cytotoxic activity of CD4⁺ and CD8⁺ T lymphocytes, resulting in enhanced antitumor responses. Anti-PD-1 or anti-PD-L1 therapy has induced tumor regression and improved clinical outcome in patients with different tumor entities, including melanoma, non-small-cell lung cancer, and renal cell carcinoma. These findings led to the approval of various anti-PD-1 or anti-PD-L1 antibodies for the treatment of tumor patients. However, the majority of patients have failed to respond to this treatment modality. Comprehensive immune monitoring of clinical trials led to the identification of potential biomarkers distinguishing between responders and non-responders, the discovery of modes of treatment resistance, and the design of improved immunotherapeutic strategies. In this review article, we summarize the evolving landscape of biomarkers for anti-PD-1 or anti-PD-L1 therapy.

Sequential Blockade of PD-1 and PD-L1 Causes Fulminant Cardiotoxicity-From Case Report to Mouse Model Validation

The combined administration of programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) inhibitors might be considered as a treatment for poorly responsive cancer. We report a patient with brain metastatic lung adenocarcinoma in whom fatal myocarditis developed after sequential use of PD-1 and PD-L1 inhibitors. This finding was validated in syngeneic tumor-bearing mice. The mice bearing lung metastases of CT26 colon cancer cells treated with PD-1 and/or PD-L1 inhibitors showed that the combination of anti-PD-1 and anti-PD-L1, either sequentially or simultaneously administered, caused myocarditis lesions with myocyte injury and patchy mononuclear infiltrates in the myocardium. A significant increase of infiltrating neutrophils in myocytes was noted only in mice with sequential blockade, implying a role for the pathogenesis of myocarditis. Among circulating leukocytes, concurrent and subsequent treatment of PD-1 and PD-L1 inhibitors led to sustained suppression of neutrophils. Among tumor-infiltrating leukocytes, combinatorial blockade increased CD8⁺ T cells and NKG2D⁺ T cells, and reduced tumor-associated macrophages, neutrophils, and natural killer (NK) cells in the lung metastatic microenvironment. The combinatorial treatments exhibited better control and anti-PD-L1 followed by anti-PD-1 was the most effective. In conclusion, the combinatory use of PD-1 and PD-L1 blockade, either sequentially or concurrently, may cause fulminant cardiotoxicity, although it gives better tumor control, and such usage should be cautionary.

Somatic mutational profiles of stage II and III gastric cancer according to tumor microenvironment immune type

We aimed to determine somatic mutational profiles of stage II/III gastric cancers (GCs) according to their tumor microenvironment immune types (TMITs), which classify cancer based on co-assessment of PD-L1 expression and CD8⁺ tumor infiltrating lymphocytes. Eighty patients with stage II/III GC were classified as follows: TMIT I (PD-L1⁺ /CD8^High ), TMIT II (PD-L1^- /CD8^Low ), TMIT III (PD-L1⁺ /CD8^Low ), and TMIT IV (PD-L1^- /CD8^High ). Deep targeted sequencing using a panel of 170 cancer-related genes was performed on an Illumina HiSeq-2500 system. Most frequently mutated genes included GNAQ (41.3%), TP53 (38.8%), CREBBP (35.0%), and MAP3K1 (35.0%). PIK3CA mutations were observed more frequently in TMIT I (45.8%) and III (66.7%), than in II (12.0%) and IV (8.0%). Other genes with enriched mutations within TMIT I included ATM (33.3%), BRCA2 (33.3%), MAP3K4 (29.2%), and FLT4 (25.0%). FGFR3, MAP3K1, and RUNX1 mutations were more frequently found in TMIT II. TMIT III had a unique somatic mutation profile harboring enriched mutations of histone modifiers including CREBBP and KMT2A, and we found FGFR2 amplification exclusively within TMIT IV. Fuzzy clustering analysis based on somatic mutation frequencies identified a hypermutated group (cluster 1) and a hypomutated group (cluster 2). Cluster 1 had significant associations with TMIT I, EBV⁺ GCs, and MSI-H GCs (P = .023, .014, and .004), and had better overall survival (P = .057) than Cluster 2. TMIT I, EBV⁺ , and MSI-H GCs were estimated to have greater tumor mutational burden (P = .023, .003, and .015). By analyzing somatic mutation profiles according to TMIT classification, we identified TMIT-specific genetic alterations that provide clues for biological linkage between GC genetics and microenvironment.

Rapid Progressive Disease After Nivolumab Therapy in Three Patients with Metastatic Renal Cell Carcinoma

BACKGROUND/AIM

Rapid progressive disease (RPD), accelerated tumour growth immediate after the initiation of immune checkpoint inhibitor therapy, has been reported in melanoma and lung cancer. Herein, we describe 3 cases of RPD during the initial phase of nivolumab treatment for metastatic renal cell carcinoma.

PATIENTS AND METHODS

The first and second patients received nivolumab in the fourth-line setting. The third patient received nivolumab therapy as third-line treatment.

RESULTS

The first patient developed severe respiratory failure due to carcinomatous lymphangiosis 14 days after initiation of nivolumab therapy. The second patient developed leg paraplegia due to rapid growth of the metastatic tumour at the sixth thoracic vertebrae 5 days later. The third patient developed grade 4 hypercalcemia due to RPD on day 3.

CONCLUSION

Clinicians should be aware of RPD during the initial phase of nivolumab therapy, especially in patients with critical lesions in the late-line setting.

Clinicopathologic implications of immune classification by PD-L1 expression and CD8-positive tumor-infiltrating lymphocytes in stage II and III gastric cancer patients

We co-assessed PD-L1 expression and CD8⁺ tumor-infiltrating lymphocytes in gastric cancer (GC), and categorized into 4 microenvironment immune types. Immunohistochemistry (PD-L1, CD8, Foxp3, E-cadherin, and p53), PD-L1 mRNA in situ hybridization (ISH), microsatellite instability (MSI), and EBV ISH were performed in 392 stage II/III GCs treated with curative surgery and fluoropyrimidine-based adjuvant chemotherapy, and two public genome databases were analyzed for validation. PD-L1⁺ was found in 98/392 GCs (25.0%). The proportions of immune types are as follows: PD-L1⁺/CD8^High, 22.7%; PD-L1⁻/CD8^Low, 22.7%; PD-L1⁺/CD8^Low, 2.3%; PD-L1⁻/CD8^High, 52.3%. PD-L1⁺/CD8^High type accounted for majority of EBV⁺ and MSI-high (MSI-H) GCs (92.0% and 66.7%, respectively), and genome analysis from public datasets demonstrated similar pattern. PD-L1⁻/CD8^High showed the best overall survival (OS) and PD-L1⁻/CD8^Low the worst (P < 0.001). PD-L1 expression alone was not associated with OS, however, PD-L1⁻/CD8^High type compared to PD-L1⁺/CD8^High was independent favorable prognostic factor of OS by multivariate analysis (P = 0.042). Adaptation of recent molecular classification based on EBV, MSI, E-cadherin, and p53 showed no significant survival differences. These findings support the close relationship between PD-L1/CD8 status based immune types and EBV⁺, MSI-H GCs, and their prognostic significance in stage II/III GCs.

Immune Monitoring of Cancer Patients Prior to and During CTLA-4 or PD-1/PD-L1 Inhibitor Treatment

Targeting the immune checkpoint receptors cytotoxic T lymphocyte antigen 4 (CTLA-4), programmed cell death protein 1 (PD-1), or programmed cell death 1 ligand 1 (PD-L1) represents a very attractive treatment modality for tumor patients. The administration of antibodies against these receptors can promote efficient antitumor effects and can induce objective clinical responses in about 20–40% patients with various tumor types, accompanied by improved survival. Based on their therapeutic efficiency, several antibodies have been approved for the treatment of tumor patients. However, many patients do not respond to checkpoint inhibitor therapy. Therefore, the identification of biomarkers is required to guide patient selection for this treatment modality. Here, we summarize recent studies investigating the PD-L1 expression or mutational load of tumor tissues as well as the frequency and phenotype of immune cells in tumor patients prior to and during CTLA-4 or PD-1/PD-L1 inhibitor treatment.

The relationship between the PD-1/PD-L1 pathway and DNA mismatch repair in cervical cancer and its clinical significance

Background

According to recent clinical observations, deficient DNA mismatch repair (dMMR) is capable of improving antitumor effects of the PD-1/PD-L1 pathway, suggesting that dMMR may act as a prognostic indicator of PD-1/PD-L1 antibody drugs. In this study, we examined the dMMR and PD-1/PD-L1 expression, as well as explored the correlation of dMMR status with PD-1/PD-L1 expression in cervical cancer patients, in order to optimize cervical cancer patient selection for PD-1/PD-L1 antibody drug treatment, which is helpful to avoid adverse effects and keep costs manageable.

Methods

Sixty-six tissue samples from patients with squamous cell carcinoma were collected, and data of their clinical characteristics were also gathered. Based on these samples, the expression levels of MLH1, MSH2, and PD-L1 in cancer cells were tested by immunohistochemical assay (IHC). Moreover, PD-1/PD-L1 expression in tumor-invading lymphocytes (TILs) was detected by IHC as well. Six single-nucleotide-repeat markers of microsatellite instability (MSI), including NR-27, MONO-27, BAT-25, NR-24, NR-21, and BAT-26, were tested by capillary electrophoresis sequencer analysis. According to expression of MLH1, MSH2 and the MSI test, all 66 cases were divided into dMMR or proficient DNA mismatch repair (pMMR) groups. The comparisons of dMMR and PD-L1 in cancer cells and of PD-1/PD-L1 in TILs were conducted categorized by age, childbearing history, history of abortion, ethnicity, and cancer cell differentiation subgroup. Furthermore, PD-L1 levels in cancer cells and PD-1/PD-L1 in TILs were analyzed and compared in both dMMR and pMMR subgroups.

Results

Of the patient samples, 25.8% were associated with dMMR. PD-L1 in cancer cells, PD-L1 in TILs, and PD-1 in TILs took up 59.1%, 47.0%, and 60.6%, respectively. The data indicated that both dMMR and PD-L1 overexpression resulted from lower cancer differentiation, more incidences of childbearing, and a history of abortion. Abortion could significantly increase PD-1 expression levels in TILs. Additionally, more incidence of childbearing or older age (35–55 years) was able to upregulate PD-L1 expression in TILs. Statistical difference of PD-L1 in cancer cells could be observed between dMMR and pMMR subgroups. In the dMMR group, PD-L1 in cancer cells and PD-1 in TILs had no correlation (r_s=0.161, p=0.537), but in the pMMR group, they had good correlation (r_s=0.645, p<0.001).

Conclusion

According to prior studies and our own experiments, PD-L1 in both cancer cells and TILs and PD-1 in TILs are widely observed in cervical cancer patients, indicating that there may be potential to apply PD-1/PD-L1 antibody drugs in cervical cancer. dMMR patients are associated with higher PD-L1 expression compared with pMMR ones, which suggested that PD-1/PD-L1 antibody drugs may work well in dMMR cervical cancer patients. Moreover, in patients with more incidences of childbearing or abortion, dMMR may be a molecular detection target for clinical application of PD-1/PD-L1 antibody drugs.

PD-L1 expression is associated with p16INK4A expression in non-oropharyngeal head and neck squamous cell carcinoma

PD-L1 expression is critical in helping tumor cells evade the immune system. However, the level of PD-L1 expression in non-oropharyngeal head and neck squamous cell carcinoma (non-OPHNSCC) and its association with patient prognosis remains unclear. A retrospective clinicopathological analysis was performed on 106 patients with non-OPHNSCC diagnosed between 2007 and 2014. In the current study, tissue arrays from paraffin-embedded non-OPHNSCC samples obtained from patients were constructed, and PD-L1 and p16^INK4A expression were determined using immunohistochemistry. Systemic inflammatory factors, including C-reactive protein, serum white blood cell, neutrophil, monocyte and lymphocyte counts were also analyzed. The current study demonstrated that PD-L1 was overexpressed in 32.1% (34/106) and p16^INK4A in 20.8% (22/106) of patients. The expression of PD-L1 was associated with p16^INK4A expression (P<0.01) but was not associated with levels of systemic inflammatory factors. Tumor stage was determined to be a significant prognostic value (stage I/II vs. III/IV, P=0.03), however, PD-L1, p16^INK4A or other clinicopathological factors were not. The current study identified an association between PD-L1 and p16^INK4A expression in non-OPHNSCC. This may facilitate the development of anti-PD1/PDL1 therapies to treat patients with head and neck cancer.

Evaluation of rare but severe immune related adverse effects in PD-1 and PD-L1 inhibitors in non-small cell lung cancer: a meta-analysis

Background

Programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) inhibitor therapy is showing marked efficacy in advanced non-small cell lung cancer (NSCLC). Meanwhile, it is concomitant with distinctive immune-related adverse effects. We aim to describe the incidence of pneumonitis and other rare but severe immune-related adverse effects (IRAEs), as well as treatment related deaths. In addition, we analyze the differences in incidence of pneumonitis between PD-1 and PD-L1 inhibitors and standard-of-care chemotherapy.

Methods

PubMed was searched up to 24 March 2017 for clinical trials of PD-1 inhibitors (nivolumab and pembrolizumab) and PD-L1 inhibitors (atezolizumab, avelumab and durvalumab) in treatment of NSCLC. Besides, references of relevant articles were screened.

Results

Finally, 22 trials were included in our study, 14 with data of pneumonitis, 19 with other severe IRAEs or treatment related deaths and 5 with control groups. Incidence of all-grade pneumonitis was 2.9% (95% CI, 2.0-4.8%) and grade 3 or higher pneumonitis 2.0% (95% CI, 1.0-2.0%). Incidence of all-grade pneumonitis in PD-1 and PD-L1 inhibitor therapy (n=1,313) was significantly higher than that in chemotherapy (n=918) (OR=2.35, 95% CI, 1.32-4.20, P=0.004), but had no significance in grade 3-5 pneumonitis. Incidence of cardiorespiratory arrest (n=537) was 1.0% (95% CI, 0-2.0%), cardiac failure (n=214) 2.0% (95% CI, 1.0-5.7%), myocardial infarction (n=402) 1.0% (95% CI, 0-3.8%), stroke (n=135) 2.0% (95% CI, 0-13.0%), disease progression (n=391) 1.0% (95% CI, 0-2.9%), pancreatitis (n=700) 1.0% (95% CI, 0-2.0%) and severe skin reactions (n=836) 2.0% (95% CI, 1.0-3.8%). Incidence of treatment related deaths was 0.7%.

Conclusions

Immune related adverse effects can on occasion be life-threatening even though usually rare. Incidence of pneumonitis in PD-1 and PD-L1 inhibitors was significantly higher than that in chemotherapy. More studies should be conducted to investigate the incidence of these rare but life-threatening IRAEs.

Association between PD-L1 and HPV status and the prognostic value for HPV treatment in premalignant cervical lesion patients

The difference of PD-L1 expression between only HPV-positive patients and premalignant cervical lesion patients did not be reported in present studies. And to test the PD-L1 expression in some cervical cell lesion studies using cervical exfoliated cells sample also was ignored. Meanwhile, the PD-L1 expression as a predictive biomarker still existed controversy. So in the study, first to compare the expression of PD-L1 between only HPV-positive patients and premalignant cervical lesion patients, then to research the association between PD-L1 and HPV status, lastly to explore the possible prognostic value for HPV treatment in premalignant cervical lesion patients.Cervical exfoliated cells samples of 54 premalignant cervical lesion patients with HPV16 infection were collected; meanwhile the cervical exfoliated cells samples from 20 healthy women without HPV infection and 20 patients with only HPV16 infection but cervical cytology normal were collected as 2 control groups. Flow-through hybridization and gene chip (FHGC) was used to detect the HPV type, the PD-L1 expression was tested by Flow cytometry analysis, the methylation-sensitive high-resolution melting (MS-HRM) was used to test the HPV16 L1 gene methylation. The 54 premalignant cervical lesion patients were followed up in 18 months to assess the prognostic value of PD-L1 for HPV treatment.The PD-L1 positive cell rate and mean fluorescence intensity of PD-L1 positive cell in premalignant cervical lesion patients with HPV16 infection were higher than 2 control groups. Mean fluorescence intensity of PD-L1 positive cell were increased in 54 cases when existing multiple HPV status and high HPV16-L1 gene methylation (L1 gene methylation more than 50%). High PD-L1 expression (PD-L1 positive cell rate more than 10%), high HPV16-L1 gene methylation, and multiple HPV infection status could prolong the time to clean HPV infection by Kaplan-Meier analysis. Multivariate Cox proportional hazards analysis also showed that all of high PD-L1 expression, high HPV-L1 methylation, and multiple HPV infection status should increase the risk of HPV unclearance in premalignant cervical lesion patients; the hazard ratio (HR) was 2.043 (CI: 1.050-3.973), 2.797 (CI: 1.277-6.122), and 3.050 (CI: 1.406-6.615).PD-L1 expression only was correction with HPV infection when the infection induced the cervical cells to create the lesion. PD-L1 was the risk factor of HPV unclearance in premalignant cervical lesion patients, so anti-PD-L1 therapy could be a potential effectiveness way of HPV infection in premalignant cervical lesion patients.

Immunomodulatory antibodies for the treatment of lymphoma: Report on the CALYM Workshop

In November 2015, the CALYM Carnot Institute held a 2-d workshop to discuss the current and future development of immunomodulatory antibodies for the treatment of lymphoma. Highlights from the workshop are presented in this article.

Essential role of program death 1-ligand 1 in regulatory T-cell-afforded protection against blood-brain barrier damage after stroke

BACKGROUND AND PURPOSE

Our recent research revealed that adoptively transferred regulatory T cells (Tregs) reduced acute ischemic brain injury by inhibiting neutrophil-derived matrix metalloproteinase-9 (MMP-9) and protecting against blood-brain barrier damage. The mechanisms underlying Treg interactions with neutrophils remain elusive. This study evaluates the contribution of program death 1-ligand 1 (PD-L1) to Treg-mediated neutrophil inhibition and neuroprotection after cerebral ischemia.

METHODS

In vitro experiments were performed using a transwell system or a coculture system allowing cell-to-cell contact. Focal cerebral ischemia was induced in mice for 60 minutes. Tregs (2×10(6)) isolated from donor animals (wild-type or PD-L1-/-) were intravenously injected into ischemic recipients 2 hours after middle cerebral artery occlusion (MCAO). MMP-9 production, blood-brain barrier permeability, and brain infarct were assessed at 1 or 3 days after MCAO.

RESULTS

In vitro experiments reveal that Treg-mediated inhibition of neutrophil MMP-9 required direct cell-to-cell contact. The suppression of MMP-9 was abolished when Tregs were pretreated with PD-L1 neutralizing antibodies or when neutrophils were pretreated with PD-1 antibodies. In vivo studies confirmed that intravenous administration of Tregs pretreated with PD-L1 antibodies or Tregs isolated from PD-L1-deficient mice failed to inhibit MMP-9 production by blood neutrophils 1 day after 60 minutes MCAO. Furthermore, the blood-brain barrier damage after MCAO was greatly ameliorated in PD-L1-competent Treg-treated mice but not in PD-L1-compromised Treg-treated mice. Consequently, PD-L1 dysfunction abolished Treg-mediated brain protection and neurological improvements 3 days after MCAO.

CONCLUSIONS

PD-L1 plays an essential role in the neuroprotection afforded by Tregs against cerebral ischemia by mediating the suppressive effect of Tregs on neutrophil-derived MMP-9.

PD-L1 is increased in the spinal cord and infiltrating lymphocytes in experimental allergic encephalomyelitis

Experimental allergic encephalomyelitis is a mouse model of human multiple sclerosis with similar pathology and pathogenesis. Th1 cells play an important role in the pathogenesis of experimental allergic encephalomyelitis. This study determined the potential effect of programmed cell death 1 ligand 1 in the pathogenesis of experimental allergic encephalomyelitis induced by injecting myelin oligodendrocyte glycoprotein, complete Freund's adjuvant and Bordetella pertussis toxin into C57BL/6J mice. Experimental allergic encephalomyelitis mice developed disease and showed inflammatory changes in the central nervous system by hematoxylin-eosin staining of spinal cord pathological sections, demyelination by Luxol fast-blue staining and clinical manifestations. The expression of programmed cell death 1 ligand 1 in mice was detected by immunohistochemistry, flow cytometry and western blot analysis. The expression of programmed cell death 1 ligand 1 in the spinal cord and splenocytes of mice was significantly increased compared with normal mice. Our findings suggest the involvement of programmed cell death 1 ligand 1 in the pathogenesis of experimental allergic encephalomyelitis and suggest this should be studied in multiple sclerosis.

PD-L1 gene expression in Japanese lung cancer patients

An imbalance in immune regulation affects tumor-specific T-cell immunity in the cancer microenvironment and reshapes tumor progression and metastasis. Blockade of interactions of immune function mediates anti-tumor activity in preclinical models. In the present study, we investigated programmed cell death 1 ligand 1 (PD-L1) mRNA expression by real-time polymerase chain reaction (RT-PCR) using a LightCycler in surgically treated non-small cell lung cancer (NSCLC) cases. This study included 123 surgically removed NSCLC cases for mRNA level analyses. The PD-L1/β-actin mRNA levels showed no marked difference in lung cancer (131.398±421.596) and adjacent normal lung tissues (78.182±254092, P=0.1482). The tumor/normal (T/N) ratio of PD-L1/β-actin mRNA levels was more than 2 in 49 cases and more than 1 in 63 cases. No difference was found in the T/N ratio of PD-L1/β actin mRNA levels among factors inlcuding gender, age, smoking status and pathological subtypes. The T/N ratio of PD-L1/β actin mRNA levels was markedly higher in pathological T4 cases (15.811±36.883) compared to T1 cases (3.492±8.494, P=0.0235). However, the PD-L1 mRNA status did not correlate with lymph node metastasis status. Thus, PD-L1 may drive tumor invasion, while providing a candidate for blockade of its function as a strategy to antagonize the progression process in NSCLC.