Retrospective Analysis of HLA Class II-Restricted Neoantigen Peptide-Pulsed Dendritic Cell Vaccine for Breast Cancer.

: Neoantigens have attracted attention as ideal therapeutic targets for anti-tumour immunotherapy because the T cells that respond to neoantigens are not affected by central immune tolerance. Recent findings have revealed that the activation of CD4-positive T cells plays a central role in antitumor immunity, and thus targeting human leukocyte antigen (HLA) class II-restricted neoantigens, which are targets of CD4-positive T cells, is of significance. However, there are very few detailed reports of neoantigen vaccine therapies that use an HLA class II-restricted long peptide.

Inhibition of PTPN3 Expressed in Activated Lymphocytes Enhances the Antitumor Effects of Anti-PD-1 Therapy in Head and Neck Cancer, Especially in Hypoxic Environments.

In the tumor microenvironment, wherein cytotoxic lymphocytes interact with cancer cells, lymphocyte exhaustion, an immune checkpoint inhibitor target, is promoted. However, the efficacy of these inhibitors is limited, and improving response rates remains challenging. We previously reported that protein tyrosine phosphatase nonreceptor type (PTPN) 3 is a potential immune checkpoint molecule for activated lymphocytes and that PTPN3 inhibition should be a focus area for cancer immunotherapy development.

Immunological analysis of hybrid neoantigen peptide encompassing class I/II neoepitope-pulsed dendritic cell vaccine.

Neoantigens/ are tumor-specific antigens that evade central immune tolerance mechanisms in the thymus. Long-term tumor-specific cytotoxic T lymphocyte activity maintenance requires class II antigen-reactive CD4 T cells. We had previously shown that intranodal vaccination with class I neoantigen peptide-pulsed dendritic cells (DCs) induced a robust immune response in a subset of patients with metastatic cancer.

PTPN3 inhibition contributes to the activation of the dendritic cell function to be a promising new immunotherapy target.

Purpose: In a previous study, protein tyrosine phosphatase non-receptor type (PTPN) 3 was identified as an immune checkpoint molecule in lymphocytes, and its potential as a novel target for cancer immunotherapy was anticipated. However, evaluation of dendritic cell (DC) function as antigen-presenting cells is critical for the development of immunotherapy. In this study, we aimed to analyze the biological effect of PTPN3 on DCs induced from human peripheral blood monocytes obtained from healthy individuals.

Contribution of pre-existing neoantigen-specific T cells to a durable complete response after tumor-pulsed dendritic cell vaccine plus nivolumab therapy in a patient with metastatic salivary duct carcinoma.

Although immune checkpoint inhibitors (ICIs) have emerged as new therapeutic options for refractory cancer, they are only effective in select patients. Tumor antigen-pulsed dendritic cell (DC) vaccine therapy activates tumor-specific cytotoxic T lymphocytes, making it an important immunotherapeutic strategy. Salivary ductal carcinoma (SDC) carries a poor prognosis, including poor long-term survival after metastasis or recurrence.

Efficacy of Intranodal Neoantigen Peptide-pulsed Dendritic Cell Vaccine Monotherapy in Patients With Advanced Solid Tumors: A Retrospective Analysis.

Background/aim: Neoantigens are tumor-specific antigens that emerge due to gene mutations in tumor cells, and are highly antigenic epitopes that escape central immune tolerance in the thymus, making cancer vaccine therapy a desirable option.

Patients And Methods: Tumor neoantigens were predicted in 17 patients with advanced cancer. They were resistant to the standard treatment regime, and their synthetic peptides were pulsed to the patient's monocyte-derived dendritic cells (DCs), and administered to the patient's lymph nodes via ultrasound.

TrkB/BDNF Signaling Could Be a New Therapeutic Target for Pancreatic Cancer.

Background/aim: Tropomyosin-related kinase B (TrkB)/brain-derived neurotrophic factor (BDNF) signaling plays a role in inducing malignant phenotypes in several aggressive types of cancers. To create a conclusive therapy targeting TrkB/BDNF signaling in solid refractory cancers, the biological significance of TrkB/BDNF signaling was analyzed in pancreatic ductal adenocarcinoma (PDAC) cells.

Materials And Methods: Three PDAC cell lines were used as target cells to investigate proliferation and invasiveness.

Neoantigens elicit T cell responses in breast cancer.

Neoantigens are tumour-specific antigens that arise from non-synonymous mutations in tumour cells. However, their effect on immune responses in the tumour microenvironment remains unclear in breast cancer. We performed whole exome and RNA sequencing of 31 fresh breast cancer tissues and neoantigen prediction from non-synonymous single nucleotide variants (nsSNVs) among exonic mutations.

PTPN3 is a potential target for a new cancer immunotherapy that has a dual effect of T cell activation and direct cancer inhibition in lung neuroendocrine tumor.

In our previous study, we found that inhibition of protein tyrosine phosphatase non-receptor type 3 (PTPN3), which is expressed in lymphocytes, enhances lymphocyte activation, suggesting PTPN3 may act as an immune checkpoint molecule. However, PTPN3 is also expressed in various cancers, and the biological significance of PTPN3 in cancer cells is still not well understood, especially for lung neuroendocrine tumor (NET).Therefore, we analyzed the biological significance of PTPN3 in small cell lung cancer and examined the potential for PTPN3 inhibitory treatment as a cancer treatment approach in lung NET including small cell lung cancer (SCLC) and large cell neuroendocrine cancer (LCNEC).

Mutant Promotes NKG2D T Cell Infiltration and CD155 Dependent Immune Evasion.

Background/aim: Roles for mutant (mt) KRAS in the innate immune microenvironment in colorectal cancer (CRC) were explored.

Materials And Methods: Human CRC HCT116-derived, mtKRAS-disrupted (HKe3) cells that express exogenous mtKRAS and allogenic cytokine-activated killer (CAK) cells were co-cultured in 3D floating (3DF) culture. The anti-CD155 antibody was used for function blocking and immuno histochemistry.

Patched 1-interacting Peptide Represses Fibrosis in Pancreatic Cancer to Augment the Effectiveness of Immunotherapy.

Pancreatic ductal adenocarcinoma (PDAC) is resistant to immunotherapy. As a factor of resistance, the dense fibrosis of this cancer acts as a barrier to inhibit immune cell infiltration into a tumor. We examined the influence of a Hedgehog signal inhibitor, Patched 1-interacting peptide, on fibrosis, infiltration of immune cells, and immunotherapeutic effects on PDAC.

PTPN3 expressed in activated T lymphocytes is a candidate for a non-antibody-type immune checkpoint inhibitor.

It has been shown that protein tyrosine phosphatase non-receptor type (PTPN) 3 inhibits T-cell activation. However, there is no definitive conclusion about how the inhibition of PTPN3 in lymphocytes affects immune functions in human lymphocytes. In the present study, we showed that PTPN3 inhibition significantly contributes to the enhanced activation of activated human lymphocytes.

Usefulness of the nCounter Analysis System to Monitor Immune-related Biomarkers in PBMCs During Anti-PD-1 Therapy.

Background/aim: Immune checkpoint inhibitors (ICIs) have dramatically changed the clinical outcomes of advanced tumours. However, biomarkers for monitoring immunological features during immunotherapy remain unclear, especially those in the peripheral blood, which are easily available. This study evaluated the usefulness of nCounter Analysis System in identifying immunological biomarkers in peripheral blood mononuclear cells (PBMCs) during ICI therapy.

Liprin-α4 as a New Therapeutic Target for SCLC as an Upstream Mediator of HIF1α.

Background/aim: Small-cell lung cancer (SCLC) remains one of deadliest types of cancers. Cis-diamminedichloroplatinum (CDDP) is a key chemotherapeutic agent for SCLC, however, its therapeutic effect is limited. Recently, hypoxia in the cancer microenvironment has been suggested to influence the effect of cancer therapy.

RBPJ and MAML3: Potential Therapeutic Targets for Small Cell Lung Cancer.

Background/aim: Small cell lung cancer (SCLC) is still a deadly type of cancer for which there are few effective therapeutic strategies. Development of a new molecule targeting agent is urgently desired. Previously we showed that recombination signal binding protein for immunoglobulin-kappa-J region (RBPJ) and mastermind-like 3 (MAML3) are new therapeutic targets for pancreatic cancer.

Catumaxomab with Activated T-cells Efficiently Lyses Chemoresistant EpCAM-positive Triple-negative Breast Cancer Cell Lines.

Background/aim: Epithelial cell adhesion molecule (EpCAM) is expressed in various types of cancer, including breast cancer, and is correlated with metastasis, invasion, therapeutic resistance and prognosis. Moreover, several cell surface markers, such as CD44 and EpCAM, are molecular targets on cancer stem-like cells of breast cancer. The aim of this study was to investigate whether catumaxomab, a clinical-grade bispecific antibody that binds to both EpCAM on tumor cells and CD3 on T-cells, combined with activated T-cells can eliminate chemoresistant triple-negative breast cancer (TNBC) cells in vitro.

Combined Gemcitabine and Metronidazole Is a Promising Therapeutic Strategy for Cancer Stem-like Cholangiocarcinoma.

Background/aim: Metronidazole (MNZ) is a common antibiotic that exerts disulfiram-like effects when taken together with alcohol. However, the relationship between MNZ and aldehyde dehydrogenase (ALDH) activity remains unclear. This study investigated whether MNZ reduces cancer stemness by suppressing ALDH activity and accordingly reducing the malignancy of cholangiocarcinoma (CCA).

Hedgehog signaling regulates PDL-1 expression in cancer cells to induce anti-tumor activity by activated lymphocytes.

We investigated whether hypoxia-induced activation of Hh signaling contributes to PDL-1 expression in cancer and whether it affects the anti-tumor function of activated lymphocytes. Hypoxia augmented PDL-1 expression and inhibition of Hh signaling reduced PDL-1 expression under hypoxia. When activated lymphocytes were cocultured with cancers treated with a Hh inhibitor, activated lymphocyte cell numbers increased under hypoxia.

Resveratrol Overcomes Cellular Resistance to Vemurafenib Through Dephosphorylation of AKT in BRAF-mutated Melanoma Cells.

Background/aim: The serine/threonine-protein kinase B-Raf (BRAF) V600E mutant (BRAF(V600E)) inhibitor vemurafenib, has improved clinical outcomes for patients with BRAF(V600E) melanoma, but acquired cellular resistance mediated by AKT serine/threonine kinase 1 (AKT) phosphorylation limits its efficacy. We examined the effect of resveratrol on vemurafenib-resistant melanoma cells.

Materials And Methods: A vemurafenib-resistant human metastatic melanoma cell line positive for the BRAF V600E mutation was established.

Hypoxic Conditions Promote Gemcitabine Sensitivity in a Pancreatic Cancer Stem Cell Line.

Development of an effective therapeutic strategy for refractory pancreatic cancer must consider whether chemosensitivity can be induced in chemoresistant cells. We established a pancreatic cancer stem cell-rich cell line using TIG-1 feeder cells and leukemia inhibitory factor (LIF)-rich SNL76/7 conditioned medium. We generated a cell line, namely YNPC031312-B, following isolation of cells from the malignant ascites of a patient with gemcitabine-resistant pancreatic cancer.

CD24 suppresses malignant phenotype by downregulation of SHH transcription through STAT1 inhibition in breast cancer cells.

Hedgehog (Hh) signaling has been found to be activated in breast cancer stem cells (BCSCs). However, the precise role of the BCSCs marker, CD24, remains unclear. Here, we describe a relationship between CD24 and Sonic Hedgehog (SHH), and reveal a role for this relationship in the induction of a malignant phenotype of breast cancer.

NKG2D-directed cytokine-activated killer lymphocyte therapy combined with gemcitabine for patients with chemoresistant metastatic solid tumors.

Natural-killer group 2, member D (NKG2D) is an activating receptor found on activated natural killer cells and on activated T-cells, here termed cytokine-activated killer (CAK) cells. NKG2D ligands are expressed on various human cancer types. Gemcitabine is an anticancer drug which is a less immune-destructive agent than others.

An epithelial cell adhesion molecule- and CD3-bispecific antibody plus activated T-cells can eradicate chemoresistant cancer stem-like pancreatic carcinoma cells in vitro.

Cancer stem-like properties of various types of cancer, including pancreatic cancer, one of the most aggressive types, correlate with metastasis, invasion, and therapeutic resistance. More importantly, chemoresistance in cancer stem-like cells (CSLCs) is a critical problem for eradication of pancreatic cancer. Several cell surface markers, such as CD44 and epithelial cell adhesion molecule (EpCAM), are molecular targets on CSLCs of pancreatic carcinoma.

Random migration contributes to cytotoxicity of activated CD8+ T-lymphocytes but not NK cells.

Activated lymphocytes have the ability to undergo non-directional cell movement known as random migration, although the biological role for this remains unclear. Herein, we investigated how random migration affects cytotoxicity of activated lymphocytes using time-lapse imaging analysis. The kinetics of random migration paralleled cytotoxicity in activated lymphocytes.