Reply: Lymph stasis promotes tumor growth

Our study suggested that surgical damage of the lymphatic system promotes tumor progression via impaired immune response. However, as pointed out by Valerio et al, lymph stasis is likely to induce immune stasis, resulting in not only enhanced tumor growth but also tumor generation. Although mechanisms of the tumor generation may not only include impaired immune response but also other factors induced by lymph stasis, we should avoid unnecessary lymphatic disruption in any surgeries and carefully consider the flap design to minimalize lymphatic disruption even in cases with benign tumors.

NK Cells Control Tumor-Promoting Function of Neutrophils in Mice

Although natural killer (NK) cells are recognized as direct antitumor effectors, the ability of NK cells to control cancer-associated inflammation, which facilitates tumor progression, remains unknown. In this study, we demonstrate that NK cells control tumor-promoting inflammation through functional modification of neutrophils. NK cells control the tumor-promoting function of neutrophils through an IFNγ-dependent mechanism. Tumor progression in an NK cell-depleted host is diminished when the IL17A-neutrophil axis is absent. In NK cell-depleted mice, neutrophils acquire a tumor-promoting phenotype, characterized by upregulation of VEGF-A expression, which promotes tumor growth and angiogenesis. A VEGFR inhibitor which preferentially suppressed tumor growth in NK cell-depleted mice was dependent on neutrophils. Furthermore, the systemic neutropenia caused by an antimetabolite treatment showed an anticancer effect only in mice lacking NK cells. Thus, NK cells likely control the tumor-promoting and angiogenic function of neutrophils. Cancer Immunol Res; 6(3); 348-57. ©2018 AACR.

Surgical damage to the lymphatic system promotes tumor growth via impaired adaptive immune response

BACKGROUND

Both lymph nodes (LNs) and lymphatic channels from primary sites to regional LNs are critical for initiation of adaptive immunity. However, as LNs are common metastatic sites in skin cancers, LN biopsies or dissections are frequently performed. In addition, reconstructive skin flaps after tumor resection may damage lymphatic flow from primary sites to regional LNs.

OBJECTIVE

This study was designed to investigate the effect on tumor progression by such surgeries.

METHODS

We developed a mouse model that simulates LNs dissection or skin flap that blocks lymphatic flow from primary sites to regional LNs and monitored tumor progression.

RESULTS

As a poor immunogenic tumor line, the growth of inoculated B16F10 melanoma into syngeneic C57BL/6 mice was not affected by these surgeries. However, the growth of the same cell line in allogenic Balb/c mice was accelerated while immune cell infiltration (CD4⁺ and CD8⁺ T cells) into the tumor was reduced by these surgeries. In addition, both cytotoxicity against B16F10 melanoma and numbers of apoptotic tumor cells were diminished by these surgeries. Similarly, tumor growth of the immunogenic MC38 cell line in syngeneic C57BL/6 mice was accelerated and immune cell infiltration and apoptotic tumor cells were reduced by these surgeries.

CONCLUSION

These results strongly indicate that surgical damage of the lymphatic system may promote tumor progression via impaired adaptive immune response.

Cytokine biomarkers to predict antitumor responses to nivolumab suggested in a phase 2 study for advanced melanoma

Promising antitumor activities of nivolumab, a fully humanized IgG4 inhibitor antibody against the programmed death‐1 protein, were suggested in previous phase 1 studies. The present phase 2, single‐arm study (JAPIC‐CTI #111681) evaluated the antitumor activities of nivolumab and explored its predictive correlates in advanced melanoma patients at 11 sites in Japan. Intravenous nivolumab 2 mg/kg was given repeatedly at 3‐week intervals to 35 of 37 patients enrolled from December 2011 to May 2012 until they experienced unacceptable toxicity, disease progression, or complete response. Primary endpoint was objective response rate. Serum levels of immune modulators were assessed at multiple time points. As of 21 October 2014, median response duration, median progression‐free survival, and median overall survival were 463 days, 169 days, and 18.0 months, respectively. The overall response rate and 1‐ and 2‐year survival rates were 28.6%, 54.3%, and 42.9%, respectively. Thirteen patients remained alive at the end of the observation period and no deaths were drug related. Grade 3–4 drug‐related adverse events were observed in 31.4% of patients. Pretreatment serum interferon‐γ, and interleukin‐6 and ‐10 levels were significantly higher in the patients with objective tumor responses than in those with tumor progression. In conclusion, giving repeated i.v. nivolumab had potent and durable antitumor effects and a manageable safety profile in advanced melanoma patients, strongly suggesting the usefulness of nivolumab for advanced melanoma and the usefulness of pretreatment serum cytokine profiles as correlates for predicting treatment efficacy.

Antiglycopeptide Mouse Monoclonal Antibody LpMab-21 Exerts Antitumor Activity Against Human Podoplanin Through Antibody-Dependent Cellular Cytotoxicity and Complement-Dependent Cytotoxicity

The interaction between podoplanin (PDPN) and C-type lectin-like receptor 2 (CLEC-2) is involved in tumor malignancy. We have established many monoclonal antibodies (mAbs) against human podoplanin using the cancer-specific mAb (CasMab) technology. LpMab-21, one of the mouse antipodoplanin mAbs, is of the IgG_2a subclass, and its minimum epitope was determined to be Thr76-Arg79 of the human podoplanin. Importantly, sialic acid is linked to Thr76; therefore, LpMab-21 is an antiglycopeptide mAb (GpMab). In this study, we investigated whether LpMab-21 shows antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against human podoplanin-expressing cancer cell lines in vitro and also studied its antitumor activities using a xenograft model. LpMab-21 showed high ADCC and CDC activities against not only podoplanin-expressing Chinese hamster ovary cells but also LN319 glioblastoma cells and PC-10 lung cancer cells, both of which endogenously express podoplanin. Furthermore, LpMab-21 decreased tumor growth in vivo, indicating that LpMab-21 could be useful for antibody therapy against human podoplanin-expressing cancers.

MELD and Child-Pugh Scores Are Related to Immune Status of Intrahepatic Natural Killer Cells in Liver Transplant Candidates

BACKGROUND

The role and phenotypic alterations of intrahepatic natural killer (NK) cells in liver disease were investigated. Although intrahepatic NK cells reportedly functionally deteriorate in the fibrotic liver, it remains unclear how the clinical severity of liver disease affects intrahepatic NK cells in patients with advanced liver failure.

METHODS

We analyzed the phenotypic properties of intrahepatic NK cells by using mononuclear cells extracted from ex vivo liver perfusate effluents from patients who underwent liver transplantation. The relationship between the clinical severity of liver disease and the phenotype of intrahepatic NK cells in these patients was also evaluated. To estimate the immunological responsiveness of intrahepatic NK cells, phenotypic enhancement after interleukin-2 stimulation was analyzed.

RESULTS

Intrahepatic NK cells from patients with advanced liver failure exhibited down-regulated monomodal expression of NKp46, a major activating molecule. Notably, the expression level of NKp46 decreased depending on the severity of liver disease, Model for End-Stage Liver Disease score, and Child-Pugh score rather than the etiology. After in vitro recombinant interleukin-2 stimulation, the enhancement of expression of cytotoxic molecules, NKp44, and tumor necrosis factor-related apoptosis-inducing ligand was significantly impaired in intrahepatic NK cells from patients with liver failure, concurrently with decreased expression of CD122 and interleukin-2 receptor beta.

CONCLUSIONS

Our results suggest that terminal deterioration of liver environments by chronic liver disease impairs the potential of local NK cells, depending on the severity of the deterioration. These influences of advanced liver failure on intrahepatic NK cells may be attributed to multicentric carcinogenesis in patients with liver failure.

IL-17A-producing CD30(+) Vδ1 T cells drive inflammation-induced cancer progression

Although it has been suspected that inflammation is associated with increased tumor metastasis, the exact type of immune response required to initiate cancer progression and metastasis remains unknown. In this study, by using an in vivo tumor progression model in which low tumorigenic cancer cells acquire malignant metastatic phenotype after exposure to inflammation, we found that IL‐17A is a critical cue for escalating cancer cell malignancy. We further demonstrated that the length of exposure to an inflammatory microenvironment could be associated with acquiring greater tumorigenicity and that IL‐17A was critical for amplifying such local inflammation, as observed in the production of IL‐1β and neutrophil infiltration following the cross‐talk between cancer and host stromal cells. We further determined that γδT cells expressing Vδ1 semi‐invariant TCR initiate cancer‐promoting inflammation by producing IL‐17A in an MyD88/IL‐23‐dependent manner. Finally, we identified CD30 as a key molecule in the inflammatory function of Vδ1T cells and the blockade of this pathway targeted this cancer immune‐escalation process. Collectively, these results reveal the importance of IL‐17A‐producing CD30⁺ Vδ1T cells in triggering inflammation and orchestrating a microenvironment leading to cancer progression.

Negative influence of programmed death-1-ligands on the survival of esophageal cancer patients treated with chemotherapy

The programmed death‐1/programmed death‐1 ligands (PD‐1/PD‐L) pathway plays an important role in immunological tumor evasion. However, the clinical significance of the PD‐L (L1 and L2) expression in esophageal cancer treated with chemotherapy has not been fully investigated. We examined the expression of PD‐L of the primary tumors obtained from 180 esophageal cancer patients who underwent radical resection with or without neoadjuvant chemotherapy (NAC) using immunohistochemical staining. The relationship between the expression patterns and clinico‐pathological characteristics was examined. In the present study, 53 patients (29.4%) and 88 patients (48.3%) were classified into positive for PD‐L1 and PD‐L2 expression, respectively. In all the patients examined, overall survival rates of the patients with tumors positive for PD‐L1 or PD‐L2 were significantly worse than those with tumors negative for PD‐L1 or PD‐L2 (P = 0.0010 and P = 0.0237, respectively). However, subgroup analysis showed that these tendencies are only found in the patients treated with NAC, and not in those without NAC. The patients with positive PD‐L1 expression had a significantly higher rate of NAC history (P = 0.0139), but those with positive PD‐L2 expression did not have a significantly high rate of NAC history (P = 0.6127). There is no significant relationship between PD‐L1 expression and response to chemotherapy (P = 0.3118), but patients with positive PD‐L2 expression had significantly inferior responses to chemotherapy (P = 0.0034). The PD‐1/PD‐L pathway might be an immunological mechanism associated with the long‐term effectiveness of chemotherapy in esophageal cancer patients. Further investigation into the roles of PD‐1 pathway in chemotherapy could lead to the development of better treatment options for this disease.

Augmentation of Immune Checkpoint Cancer Immunotherapy with IL18

PURPOSE

Recent clinical trials and animal models demonstrated that immune checkpoint blockade enhanced effector cell responses and tumor rejection; however, further development and improvement of cancer immunotherapy is necessary for more favorable objective responses. In this study, we examined the effect of IL18 on the antitumor effect of immune checkpoint inhibitors.

EXPERIMENTAL DESIGN

We examined the effect of IL18 on the peritoneal dissemination of CT-26 cells or tail vein injection metastasis of B16/F10 cells using antiprogrammed death-1 ligand-1 (αPD-L1) and/or anti-CTL-associated antigen-4 (αCTLA-4) mAbs.

RESULT

Massive ascites developed after intraperitoneal inoculation of CT-26, resulting in animal death within 30 days. Treatment of mice with αPD-L1 and/or αCTLA-4 significantly prolonged their survival, and a combination of the antibodies and IL18 provided a much greater therapeutic benefit. The combination modality led to the accumulation of precursor of mature natural killer (pre-mNK) cells in the peritoneal cavity together with increased CD8(+) T and decreased CD4(+)CD25(+)Foxp3(+) T cells. Depletion of the pre-mNK cells abrogated the therapeutic effects and increased the number of CD4(+)CD25(+)Foxp3(+) T cells. The combination treatment also suppressed tail vein injection metastasis of B16/F10 cells.

CONCLUSIONS

The results demonstrated that IL18 enhanced therapeutic effects of immune checkpoint blockade against peritoneal dissemination of carcinoma or tail vein injection metastasis of melanoma through accumulation of pre-mNK cells, memory-type CD8(+) T cells, and suppression of CD4(+)CD25(+)Foxp3(+) T cells. A combination of immune checkpoint inhibitors with IL18 may give a suggestion to the development of next-generation cancer immunotherapy. Clin Cancer Res; 22(12); 2969-80. ©2016 AACR.

Uremic serum contains humoral factor(s) larger than fifty kilodaltons which suppresses endothelin production in cultured endothelial cells

Direct effects of human uremic serum on the production of endothelin-1 in cultured porcine endothelial cells were examined in this study. Uremic serum decreased the level of monomeric endothelin-1 secreted into the culture medium by endothelial cells. This effect occurred at a transcriptional step because uremic serum decreased the endothelin-1 mRNA level in those cells. For the partial characterization of this inhibitory activity, uremic serum was fractionated with a centricut column. Uremic serum contains humoral factor(s) larger than 50 kD which suppress the endothelin-1 mRNA level in cultured endothelial cells.

Clinical efficacy of simultaneous splenectomy in liver transplant recipients with hepatitis C virus

BACKGROUND

Interferon (IFN) therapy is a well-established antiviral treatment for hepatitis C virus (HCV) - infected patients. However, susceptibility to thrombocytopenia is a major obstacle in its initiation or continuation, particularly in patients with HCV who underwent liver transplantation (LT). We previously showed that the coexistence of splenomegaly and thrombocytopenia could result in persistent thrombocytopenia after LT. Here we retrospectively evaluated the validity of this criterion for simultaneous splenectomy in recipients with HCV.

PATIENTS AND METHODS

Subjects included 36 recipients with HCV who received LT between January 2006 and February 2012 at Hiroshima University. We analyzed the spleen volume, body surface area, platelet (PLT) count, and rate of completion or continuation with IFN therapy in these recipients.

RESULT

Of these recipients, 30 did not require simultaneous splenectomy according to the criterion, and 24 actually did not receive simultaneous splenectomy. In this group, 21 (87.5%) started IFN therapy. Fifteen (71.4%) of these recipients completed or continued IFN therapy, whereas 13 (61.9%) achieved either a sustained virological response (SVR) or an end-of-treatment response. The PLT count increased to >100,000/mm(3) 1 month after LT in 16 (66.7%) recipients from this group.

CONCLUSION

Our criterion detected the PLT count outcome after LT in recipients with HCV and achieved a better SVR result after IFN therapy.

Long-time correlation in non-Markovian dephasing of an exciton-phonon system in InAs quantum dots

We have observed a time-correlated frequency fluctuation in non-Markovian dephasing of excitons in InAs quantum dots using a six-wave mixing technique. In this measurement, the arrival times of the excitation pulses were controlled to eliminate the influence of Markovian dephasing and to measure the pure non-Markovian behavior. The experimental result shows that the time correlation of the frequency fluctuation due to exciton-phonon interactions was maintained in the quantum dots for over 10 ps. This long-time correlation is caused by the modification of the phonon coupling distribution.

[Mechanism of action for immunotherapy drugs]

Cancer therapy utilizing cellular immunity has been developed using various reagents including stimulus for innate immunity, cytokines, vaccines, autologous cells and gene-vectors. Recently, mono-clonal antibodies have been added to the list as well. These reagents of modalities have been developed base on the findings in the basic research in cellular immunology which has been proven to have potent activities to suppress the tumor growth in either in vitro or in vivo. This review describes the characteristics of the reagents of modalities focusing on their mechanisms of action.

Sox9 is upstream of microRNA-140 in cartilage

MicroRNA-140 (miR-140) is specifically expressed in developing cartilage tissues. We have previously reported that miR-140 plays an important role during palatal cartilage development by modulating platelet-derived growth factor receptor alpha (pdgfra) in zebrafish. However, the regulatory mechanism of miR-140 in cartilage is still unknown. Using developing zebrafish, sox9a mutant (sox9a-/-) and sox9b mutant (sox9b-/-) zebrafish and SOX9 small interfering RNA in human chondrocytes, T/C-28 cells, we found that miR-140 is regulated by the cartilage master transcription regulator Sox9 in zebrafish and mammalian cells.