The Role of Anti-PD-1/PD-L1 Agents in Melanoma: Progress to Date

Single-cell transcriptomics and functional validation revealed PLEKHA5-L as a promoter of growth and migration in brain metastatic melanoma cells

Background

Melanoma brain metastasis is an lethal event. Investigating the molecules that potentially promoted melanoma metastasis is important for targeted therapy.

Methods

The transcriptional profiles of totaling 7 melanoma samples, including 4 primary and 3 brain metastatic tissues were studied on the single-cell RNA sequencing level, and the expression of PLEKHA5 was examined in tumor clusters. Then PLEKHA5 expression was validated in brain Metastatic model by left ventricular injections in nude mice. The functional effect of PLEKHA5 isoforms (Long or Short) on proliferation and migration of melanoma was studied by RNA interference, overexpression by lentivirus vector, CCK8 test, colony formation test, transwell chamber assay. The targets and signal pathways that was potentially regulated by PLEKHA5 was studied by RNA-sequencing.

Result

PLEKHA5 expression increased in brain metastatic melanoma at single cell level. PLEKH5 was constantly upregulated in brain metastatic tissue of melanoma in animal model. PLEKHA5-L had the potential for melanoma migration and proliferation by upregulating oncogenes such as HRAS, AKT3 etc. PLEKHA5-L also upregulated expression of PD-L1 and ABC transporters that were associated with therapy resistant.

Conclusion

PLEKHA5-L was potential therapeutic target for metastatic melanoma.

Immune cells in skin inflammation, wound healing, and skin cancer

Given the self-evident importance of cutaneous immunity in the maintenance of body-surface homeostasis, disturbance of the steady-state skin is inextricably intertwined with dysfunction in cutaneous immunity. It is often overlooked by people that skin, well-known as a solid physical barrier, is also a strong immunological barrier, considering the abundant presence of immune cells including lymphocytes, granulocytes, dendritic cells, and macrophages. What's more, humoral immune components including cytokines, immunoglobulins, and antimicrobial peptides are also rich in the skin. This review centers on skin inflammation (acute and chronic, infection and aseptic inflammation), wound healing, and skin cancer to elucidate the elaborate network of immune cells in skin diseases.

PD-1/PD-L1 Correlates With the Efficacy of the Treatment of Concurrent Chemoradiotherapy in Cervical Cancer

Background

Cervical cancer (CC) is the third most common cancer worldwide, with high mortality rates. The programmed cell death 1 (PD-1)/(PD-1 ligand) PD-L1 has been reported to be an effective indicator in cancer development. In this study, we aim to explore the role of PD-1/PD-L1 in the evaluation of concurrent chemoradiotherapy (CCRT) efficacy and prognosis in CC patients.

Methods

We included 55 CC patients in this study. Immunohistochemistry and flow cytometry were employed to detect the expression of PD-1, T_reg cells, CD8, and CD68 in tumor tissues, and the contents of PD-1⁺ CD8⁺ T cells, PD-1⁺ CD4⁺ T cells, and PD-1⁺ T_reg cells in the peripheral blood. The relationships of these indexes with CCRT efficacy were measured by Spearman correlation analysis, overall survival (OS), and disease-free survival (DFS) of patients were analyzed by Kaplan-Meier estimator, and the diagnostic values of these indexes in CC were assessed by a receiver operating characteristic (ROC) curve.

Results

The clinical effectivity rate of CCRT was 89.10%. The positive expressions of PD-L1, T_reg cells, PD-1⁺ CD8⁺ T cells, PD-1⁺ CD4⁺ T cells, and PD-1⁺ T_reg cells were reduced after CCRT, while the CD8 and CD68 increased. All 7 indexes had diagnostic values in evaluating CCRT efficacy and were considered the influencing factors of OS, DFS, and the prognosis of CC patients.

Conclusion

These findings indicate that PD-1/PD-L1 may be a potential indicator for the efficacy evaluation of CCRT and the prognosis of CC. This study may offer potential targets for CC treatment.

A Novel Bispecific Antibody Targeting PD-L1 and VEGF With Combined Anti-Tumor Activities

Therapeutic monoclonal antibodies (mAbs) blocking immune checkpoints have been mainly used as monotherapy. Recently, combination therapy targeting multiple immune checkpoints has recently been explored to increase anti-cancer efficacy. Particularly, a single molecule targeting more than one checkpoints has been investigated. As dual blocking of PD-1/PD-L1 and VEGF/VEGFR has demonstrated synergism in anti-tumor activities, we developed a novel bispecific antibody, termed HB0025, which is formed via fusing the domain 2 of vascular endothelial growth factor receptor 1 (VEGFR1D2) and anti-PD-L1 mAb by using mAb-Trap technology. HB0025 almost completely retains the binding affinities and the biological activities in-vitro when compared with the parent anti-PD-L1 mAb or VEGFR1D2 fusion protein. Preclinical data demonstrated that HB0025 was more effective in inhibiting cancer growth than anti PD-L1 mAb or VEGFR1D2 fusion protein. Thus, our bispecific antibody may bring about greater clinical benefits and broader indications.

Prognostic Role of Plasma PD-1, PD-L1, pan-BTN3As and BTN3A1 in Patients Affected by Metastatic Gastrointestinal Stromal Tumors: Can Immune Checkpoints Act as a Sentinel for Short-Term Survival?

Gastrointestinal stromal tumors (GISTs) represent 1% of all primary gastrointestinal tumors. Immune surveillance is often overcome by cancer cells due to the activation of immunoregulatory molecules such as programmed death protein (PD-1) and its ligand PD-L1, and butyrophilin sub-family 3A/CD277 receptors (BTN3A). Because several studies demonstrated that tumor PD-1 and PD-L1 expression may have a prominent prognostic function, this investigation aimed to discover if soluble forms of these molecules may be useful in predicting survival of metastatic GIST (mGIST) patients. Through specific ad hoc developed ELISA assays not yet available on the market, the circulating PD-1, PD-L1, BTN3A1, and pan-BTN3As levels were examined in 30 c-KIT exon 11-mutated mGIST patients, prior to imatinib therapy. Using specific thresholds derived by ROC analysis, we found that high baseline levels of sPD-1 (>8.1 ng/mL), sPD-L1 (>0.7 ng/mL), sBTN3A1 (>7.0 ng/mL), and pan-BTN3As (>5.0 ng/mL) were correlated with shorter progression-free survival (PFS) and poor prognosis. Contrariwise, subjects with lower plasma concentrations exhibited a median PFS about 20 months longer than to the earlier. Finally, an additional multivariate analysis revealed that circulating levels of sPD-L1 ≤ 0.7 ng/mL and pan-sBTN3As ≤ 5.0 ng/mL, and the absence of KIT exon 11 deletions or delins at codons 557 and/or 558 were associated with a longer PFS in mGIST patients. Our investigation, for the first time, revealed that evaluating the plasma concentration of some immune checkpoints may help prognosticate survival in mGIST patients, suggesting their potential use as prognostic biomarkers beyond the presence of KIT exon 11 Del or Delins at codons 557/558.

Implementing biological markers as a tool to guide clinical care of patients with pancreatic cancer

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A major obstacle for the effective treatment of PDAC is its molecular heterogeneity.

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Stratification of PDAC using markers highly specific, reproducible, sensitive, easily measurable and inexpensive is necessary.

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At the early stages, clinician’s priority lies in rapid diagnosis, so that the patient receives surgery without delay.

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At advanced disease stages, priority is to determine the tumor subtype and select a suitable effective treatment.

A major obstacle for the effective treatment of pancreatic ductal adenocarcinoma (PDAC) is its molecular heterogeneity, reflected by the diverse clinical outcomes and responses to therapies that occur. The tumors of patients with PDAC must therefore be closely examined and classified before treatment initiation in order to predict the natural evolution of the disease and the response to therapy. To stratify patients, it is absolutely necessary to identify biological markers that are highly specific and reproducible, and easily measurable by inexpensive sensitive techniques. Several promising strategies to find biomarkers are already available or under development, such as the use of liquid biopsies to detect circulating tumor cells, circulating free DNA, methylated DNA, circulating RNA, and exosomes and extracellular vesicles, as well as immunological markers and molecular markers. Such biomarkers are capable of classifying patients with PDAC and predicting their therapeutic sensitivity. Interestingly, developing chemograms using primary cell lines or organoids and analyzing the resulting high-throughput data via artificial intelligence would be highly beneficial to patients. How can exploiting these biomarkers benefit patients with resectable, borderline resectable, locally advanced, and metastatic PDAC? In fact, the utility of these biomarkers depends on the patient's clinical situation. At the early stages of the disease, the clinician's priority lies in rapid diagnosis, so that the patient receives surgery without delay; at advanced disease stages, where therapeutic possibilities are severely limited, the priority is to determine the PDAC tumor subtype so as to estimate the clinical outcome and select a suitable effective treatment.

Why Formalin-fixed, Paraffin-embedded Biospecimens Must Be Used in Genomic Medicine: An Evidence-based Review and Conclusion

Fresh-frozen tissue is the “gold standard” biospecimen type for next-generation sequencing (NGS). However, collecting frozen tissue is usually not feasible because clinical workflows deliver formalin-fixed, paraffin-embedded (FFPE) tissue blocks. Some clinicians and researchers are reticent to embrace the use of FFPE tissue for NGS because FFPE tissue can yield low quantities of degraded DNA, containing formalin-induced mutations. We describe the process by which formalin-induced deamination can lead to artifactual cytosine (C) to thymine (T) and guanine (G) to adenine (A) (C:G > T:A) mutation calls and perform a literature review of 17 publications that compare NGS data from patient-matched fresh-frozen and FFPE tissue blocks. We conclude that although it is indeed true that sequencing data from FFPE tissue can be poorer than those from frozen tissue, any differences occur at an inconsequential magnitude, and FFPE biospecimens can be used in genomic medicine with confidence:

Cutaneous Malignant Melanoma and Targeted Therapy Based on the Biomarkers

Malignant melanoma is the most aggressive form of cutaneous malignancy. It accounts for more than 75% of cancer-related deaths among cutaneous malignancies. It accounts for <5% of cutaneous malignancy. Numerous biomarkers are used in malignant melanoma with varying clinical applications, including diagnostic purposes, prognosis, therapeutic purpose, and targeted therapy against melanoma. Systemic chemotherapy in malignant melanoma has little benefit compared to immunotherapy and targeted therapy. The observed overall survival with systemic chemotherapy is much less compared with targeted therapy in advanced or metastatic melanoma. Various targeted therapies are currently used in melanoma treatment including BRAF inhibitors such as vemurafenib and dabrafenib; MEK inhibitors such as trametinib; anti-CTLA-4 antibodies such as ipilimumab; and anti-programmed cell death 1 antibodies such as nivolumab, pembrolizumab, and pidilizumab. This study discusses the role of biomarkers and targeted therapies based on the biomarker.

Prognostic significance of circulating PD-1, PD-L1, pan-BTN3As, BTN3A1 and BTLA in patients with pancreatic adenocarcinoma

PDAC is one of the most heterogeneous cancers with low chemotherapeutic sensitivity due to a dense stroma, a weak vasculature and significant biological aggressivity. In cancer, suppressive immune checkpoints are often hyper-activated to ensure an effective evasion of tumor cells from immune surveillance. These immune checkpoints include in part, the B7/butyrophilin-like receptors such as butyrophilin sub-family 3A/CD277 receptors (BTN3A), the B and T lymphocyte attenuator (BTLA) belonging to the B7-like receptors and the programmed death protein (PD-1) with its ligand PD-L1. We evaluated the plasma level of these markers in 32 PDAC patients (learning cohort) by ad hoc developed ELISA’s and showed that there are highly correlated. We used ROC curves and univariate analysis to characterize their prognostic relevance in these patients and showed that their plasma level can serve as survival predictor. Plasma level thresholds that correlate with less than six months survival were established for sPD-1 (>8.6 ng/ml), sPD-L1 (>0.36 ng/ml), sBTLA (>1.91 ng/ml), sBTN3A1 (>6.98 ng/ml) and pan-sBTN3A (>6.92 ng/ml). These thresholds were applied in independent validation cohort composed by 27 new samples and could efficiently discriminate short versus long PDAC survivors. Our study reveals that monitoring the concentration of soluble forms of inhibitory immune checkpoints in plasma can help predict survival in PDAC patients and therefore improve their treatments.

PD-1/PD-L1 immune checkpoint: Potential target for cancer therapy

Recent studies show that cancer cells are sometimes able to evade the host immunity in the tumor microenvironment. Cancer cells can express high levels of immune inhibitory signaling proteins. One of the most critical checkpoint pathways in this system is a tumor-induced immune suppression (immune checkpoint) mediated by the programmed cell death protein 1 (PD-1) and its ligand, programmed death ligand 1 (PD-L1). PD-1 is highly expressed by activated T cells, B cells, dendritic cells, and natural killer cells, whereas PD-L1 is expressed on several types of tumor cells. Many studies have shown that blocking the interaction between PD-1 and PD-L1 enhances the T-cell response and mediates antitumor activity. In this review, we highlight a brief overview of the molecular and biochemical events that are regulated by the PD-1 and PD-L1 interaction in various cancers.

Current status and future direction in the management of malignant melanoma

The incidence of malignant melanoma is increasing rapidly on a global scale. Although some types of melanoma, for example primary cutaneous melanoma, can be managed by surgery, metastatic melanoma cannot and it has a high mortality rate. Both oncogene and immune-targeted strategies have shown marked efficacy in some patients, but their effect on overall survival is still variable. Therefore, newer therapeutic approaches are needed. Fortunately, new advances in molecular medicine have led to an understanding of an individual patient's cancer at the genomic level. This information is now being used in all stages of cancer treatment including diagnosis, treatment selection, and treatment monitoring. This new strategy of personalized medicine may lead to marked shifts in immunotherapeutic treatment approaches such as individualized cancer vaccines and adoptive transfer of genetically modified T cells. This review provides an overview of recent approaches in cancer research and expected impact on the future of treatment for metastatic melanoma.

Identification of a gene expression signature associated with the metastasis suppressor function of NME1: prognostic value in human melanoma

Although NME1 is well known for its ability to suppress metastasis of melanoma, the molecular mechanisms underlying this activity are not completely understood. Herein, we utilized a bioinformatics approach to systematically identify genes whose expression is correlated with the metastasis suppressor function of NME1. This was accomplished through a search for genes that were regulated by NME1, but not by NME1 variants lacking metastasis suppressor activity. This approach identified a number of novel genes, such as ALDOC, CXCL11, LRP1b, and XAGE1 as well as known targets such as NETO2, which were collectively designated as an NME1-Regulated Metastasis Suppressor Signature (MSS). The MSS was associated with prolonged overall survival in a large cohort of melanoma patients in The Cancer Genome Atlas (TCGA). The median overall survival of melanoma patients with elevated expression of the MSS genes was >5.6 years longer compared with that of patients with lower expression of the MSS genes. These data demonstrate that NMEl represents a powerful tool for identifying genes whose expression is associated with metastasis and survival of melanoma patients, suggesting their potential applications as prognostic markers and therapeutic targets in advanced forms of this lethal cancer.

Sex disparity in cancer: roles of microRNAs and related functional players

A sexual dimorphism at the cellular level has been suggested to play a role in cancer onset and progression. In particular, very recent studies have unraveled striking differences between cells carrying XX or XY chromosomes in terms of response to stressful stimuli, indicating the presence of genetic and epigenetic differences determining sex-specific metabolic or phenotypic traits. Although this field of investigation is still in its infancy, available data suggest a key role of sexual chromosomes in determining cell life or death. In particular, cells carrying XX chromosomes exhibit a higher adaptive potential and survival behavior in response to microenvironmental variations with respect to XY cells. Cells from females also appear to be equipped with more efficient epigenetic machinery than the male counterpart. In particular, the X chromosome contains an unexpected high number of microRNAs (miRs), at present 118, in comparison with only two miRs localized on chromosome Y, and an average of 40-50 on the autosomes. The regulatory power of these small non-coding RNAs is well recognized, as 30-50% of all protein-coding genes are targeted by miRs and their role in cell fate has been well demonstrated. In addition, several further insights, including DNA methylation patterns that are different in males and females, claim for a significant gender disparity in cancer and in the immune system activity against tumors. In this brief paper, we analyze the state of the art of our knowledge on the implication of miRs encoded on sex chromosomes, and their related functional paths, in the regulation of cell homeostasis and depict possible perspectives for the epigenetic research in the field.

Clinical development of talimogene laherparepvec (T-VEC): a modified herpes simplex virus type-1-derived oncolytic immunotherapy

Tumor immunotherapy is emerging as a promising new treatment option for patients with cancer. T-VEC is an intralesional oncolytic virus therapy based on a modified herpes simplex virus type-1. T-VEC selectively targets tumor cells, causing regression in injected lesions and inducing immunologic responses that mediate regression at uninjected/distant sites. In a randomized phase III trial, T-VEC met its primary endpoint of improving the durable response rate vs granulocyte-macrophage colony-stimulating factor in patients with unresectable melanoma. Responses were observed in injected and uninjected regional and visceral lesions. Exploratory analyses suggested survival differences in favor of T-VEC in patients with untreated or stage IIIB/IIIC/IVM1a disease. T-VEC was generally well tolerated, the most common adverse events being flu-like symptoms. Here, we overview recent advances in cancer immunotherapy, focusing on the clinical development of T-VEC, from first-in-human studies and studies in other cancer types, to ongoing combination trials with checkpoint inhibitors.

Nivolumab: A Review in Advanced Melanoma

An improved understanding of cancer genetics and immune regulatory pathways, including those associated with evasion of immune surveillance by tumours, has culminated in the development of several targeted therapies. One such strategy that acts to negate evasion of immune surveillance by tumours is inhibition of the programmed cell death receptor-1 (PD-1) checkpoint pathway. Intravenous nivolumab (Opdivo(®)), a PD-1 checkpoint inhibitor, is approved or in pre-registration in various countries for use in adult patients with advanced melanoma, with the recommended monotherapy dosage being a 60-min infusion of 3 mg/kg once every 2 weeks. In well-designed multinational trials, as monotherapy or in combination with ipilimumab (a cytotoxic T-lymphocyte antigen 4 checkpoint inhibitor), nivolumab significantly improved clinical outcomes and had a manageable tolerability profile in adult patients with advanced melanoma with or without BRAF mutations. Nivolumab monotherapy was associated with a higher objective response rate (ORR) than chemotherapy in treatment-experienced patients and a higher ORR and prolonged progression-free survival (PFS) and overall survival than dacarbazine in treatment-naive patients. In combination with ipilimumab, nivolumab was associated with an improved ORR and prolonged PFS compared with ipilimumab monotherapy in treatment-naive patients. In addition, nivolumab monotherapy significantly prolonged PFS and improved ORRs compared with ipilimumab monotherapy. The optimal combination regimen for immune checkpoint inhibitors remains to be fully elucidated, with various combination regimens and different sequences of individual immunotherapies currently being investigated in ongoing clinical trials. Given the significant improvements in outcomes associated with nivolumab in clinical trials, nivolumab monotherapy or combination therapy is a valuable first-line or subsequent treatment option for adult patients with unresectable or metastatic melanoma, irrespective of BRAF mutation status.

The efficacy and safety of nivolumab in the treatment of advanced melanoma: a meta-analysis of clinical trials

Background

Nivolumab has become a therapeutic regimen for the treatment of patients with advanced melanoma. The goal of this study was to assess the efficacy and safety of nivolumab in patients with advanced melanoma.

Methods

A systematic search from January 2008 to August 2015 with “nivolumab” and “advanced melanoma” as search terms was performed for possible clinical trials. According to the hazard ratio and the 95% confidence interval (CI) for progression-free survival (PFS), rates of objective response, complete response, partial response, rates of toxic effects, and the efficacy and safety of nivolumab were assessed. Using the software Review Manager (version 5.3) a meta-analysis was performed.

Results

There were four trials with 1,910 patients included. Based on the four trials, the pooled hazard ratio of PFS was 0.53 (95% CI, 0.43–0.66; P<0.001). The pooled risk ratio for the objective response rate, complete response, and partial response was 2.98% (95% CI, 2.38%–3.73%; P<0.001), 3.71% (95% CI, 2.67%–5.14%; P<0.001), and 2.51% (95% CI, 2.12%–2.99%; P<0.001), respectively. Nivolumab plus ipilimumab therapy significantly increased the risk of grade 3/4 rash and fatigue.

Conclusion

Nivolumab-based therapy prolonged PFS in treatment of advanced melanoma, with less adverse effects. Nivolumab appears to be a favorable treatment option as a novel, targeted anticancer agent, for patients with advanced melanoma.

B7-H3 increases thymidylate synthase expression via the PI3k-Akt pathway

B7-H3, a member of the B7 family, has been reported to be highly expressed in colorectal cancer and is associated with poor prognosis and overall survival. In this study, we found that overexpression of B7-H3 protected SW80 and HCT8 cells from 5-fluorouracil (5-FU) using CCK-8 assays by inducing resistance to 5-FU chemotherapy. Further investigation has revealed elevated expression of thymidylate synthase (TS) and upregulation of the PI3-kinase (PI3K)/Akt pathway in B7-H3 overexpressing cells. The effects of B7-H3 on activation of the PI3K/Akt pathway and elevation of TS expression could be blocked by LY294002, a specific inhibitor of the PI3K signaling pathway. These results implied that B7-H3 can induce colorectal cancer cell resistance to 5-FU by increasing TS expression and PI3K/Akt/TS signaling and plays an important role during these processes. This study provides more proof concerning the non-immunology effect of B7 molecules, a reminder that both co-stimulatory or inhibitory effects and non-immunology effects should be devoted equal attention.

Hepatic Stellate Cells Directly Inhibit B Cells via Programmed Death-Ligand 1

We demonstrated previously that mouse hepatic stellate cells (HSCs) suppress T cells via programmed death-ligand 1 (PD-L1), but it remains unknown whether they exert any effects on B cells, the other component of the adaptive immune system. In this study, we found that mouse HSCs directly inhibited B cells and that PD-L1 was also integrally involved. We found that HSCs inhibited the upregulation of activation markers on activated B cells, as well as the proliferation of activated B cells and their cytokine/Ig production in vitro, and that pharmaceutically or genetically blocking the interaction of PD-L1 with programmed cell death protein 1 impaired the ability of HSCs to inhibit B cells. To test the newly discovered B cell-inhibitory activity of HSCs in vivo, we developed a protocol of intrasplenic artery injection to directly deliver HSCs into the spleen. We found that local delivery of wild-type HSCs into the spleens of mice that had been immunized with 4-hydroxy-3-nitrophenylacetyl-Ficoll, a T cell-independent Ag, significantly suppressed Ag-specific IgM and IgG production in vivo, whereas splenic artery delivery of PD-L1-deficient HSCs failed to do so. In conclusion, in addition to inhibiting T cells, mouse HSCs concurrently inhibit B cells via PD-L1. This direct B cell-inhibitory activity of HSCs should contribute to the mechanism by which HSCs maintain the liver's immune homeostasis.

Adolescent and young adult patients with cancer: a milieu of unique features

Adolescent and young adult (AYA) patients with cancer are a unique category of patients who, depending on age at time of diagnosis, might receive treatment from oncologists specializing either in the treatment of children or adults. In the USA, AYA oncology generally encompasses patients 15-39 years of age. AYA patients with cancer typically present with diseases that span the spectrum from 'paediatric' cancers (such as acute lymphoblastic leukaemia [ALL] and brain tumours) to 'adult' tumours (such as breast cancer and melanoma), as well as cancers that are largely unique to their age group (such as testicular cancer and bone tumours). Research indicates that outcomes of AYA patients with cancer are influenced not only by the treatment provided, but also by factors related to 'host' biology. In addition to the potential biological and cancer-specific differences between AYAs and other patients with cancer, AYA patients also often have disparate access to clinical trials and suffer from a lack of age-appropriate psychosocial support services and health services, which might influence survival as well as overall quality of life. In this Review, these issues are discussed, with a focus on two types of AYA cancer--ALL and melanoma--highlighting findings arising from the use of emerging technologies, such as whole-genome sequencing.