Non-classical Monocytes Enhance the Efficacy of Immune Checkpoint Inhibitors on Colon Cancer in a Syngeneic Mouse Model

BACKGROUND/AIM

The response rate to immune checkpoint inhibitors (ICIs) is approximately 10%-30% and only in a few cancer types. In the present study, we determined whether non-classical monocytes (NCMs) could enhance ICI efficacy in colon cancer using a syngeneic mouse model.

MATERIALS AND METHODS

The MC38 C57BL/6 mouse colon cancer model was used. Cells collected from the bone marrow of C57BL/6 mice were cultured, and NCMs were fractionated by cell sorting and administered via the tail veins to the mice implanted with MC38 cells. The anti-mouse PD-L1 antibody was administered three times, and tumor volume and overall survival were observed.

RESULTS

More tumors were eradicated and more complete response occurred, after cotreatment with ICIs and NCMs than after treatment with ICIs alone. Moreover, no efficacy was observed when NCMs were administered alone.

CONCLUSION

NCMs enhance ICI efficacy. The underlying mechanisms and clinical applications will be studied in the future.

Novel quantitative immunohistochemical analysis for evaluating PD-L1 expression with phosphor-integrated dots for predicting the efficacy of patients with cancer treated with immune checkpoint inhibitors

Introduction

Programmed cell death ligand 1 (PD-L1) expression in tumor tissues is measured as a predictor of the therapeutic efficacy of immune checkpoint inhibitors (ICIs) in many cancer types. PD-L1 expression is evaluated by immunohistochemical staining using 3,3´-diaminobenzidine (DAB) chronogenesis (IHC-DAB); however, quantitative and reproducibility issues remain. We focused on a highly sensitive quantitative immunohistochemical method using phosphor-integrated dots (PIDs), which are fluorescent nanoparticles, and evaluated PD-L1 expression between the PID method and conventional DAB method.

Methods

In total, 155 patients with metastatic or recurrent cancer treated with ICIs were enrolled from four university hospitals. Tumor tissue specimens collected before treatment were subjected to immunohistochemical staining with both the PID and conventional DAB methods to evaluate PD-L1 protein expression.

Results

PD-L1 expression assessed using the PID and DAB methods was positively correlated. We quantified PD-L1 expression using the PID method and calculated PD-L1 PID scores. The PID score was significantly higher in the responder group than in the non-responder group. Survival analysis demonstrated that PD-L1 expression evaluated using the IHC-DAB method was not associated with progression-free survival (PFS) or overall survival (OS). Yet, PFS and OS were strikingly prolonged in the high PD-L1 PID score group.

Conclusion

Quantification of PD-L1 expression as a PID score was more effective in predicting the treatment efficacy and prognosis of patients with cancer treated with ICIs. The quantitative evaluation of PD-L1 expression using the PID method is a novel strategy for protein detection. It is highly significant that the PID method was able to identify a group of patients with a favorable prognosis who could not be identified by the conventional DAB method.

Low syntaxin 17 expression in donor liver is associated with poor graft prognosis in recipients of living donor liver transplantation

AIM

Liver transplantation (LT) is the only curative therapy for decompensated liver cirrhosis. For recipients of living donor LT (LDLT), restoration of liver function after transplantation is highly dependent on liver regenerative capacity, which requires large amounts of intracellular energy. Mitochondrial metabolism provides a stable supply of adenosine 5'-triphosphate (ATP) for liver regeneration. Mitophagy is a selective process in which damaged, non-functional mitochondria are degraded and replaced with new functional mitochondria. We investigated the relationship between expression of Syntaxin17 (STX17), a key protein in mitophagy regulation, in donor livers and graft survival.

METHODS

We examined STX17 expression in grafts from 143 LDLT donors who underwent right lobe resection and investigated the relationship between STX17 expression and graft function. We investigated the correlations among STX17 expression, mitochondrial membrane potential and cell proliferation, using a STX17-knockdown hepatocyte cell line.

RESULTS

Recipients transplanted with low STX17-expression grafts had significantly lower graft survival rates than recipients transplanted with high STX17-expression grafts (88.9% vs. 100%, p < 0.01). Multivariate analysis showed that low STX17 expression (HR: 10.7, CI: 1.29-88.0, p < 0.05) and the absence of splenectomy (HR: 6.27, CI: 1.59-24.8, p < 0.01) were independent predictive factors for small-for-size graft syndrome, which is the severe complication in LDLT. In the vitro experiments, the percentage of depolarized damaged mitochondria was increased in the STX17-knockdown hepatocyte cell line, suggesting decreased mitophagy and ATP synthesis. Cell proliferation was significantly decreased in the STX17-knockdown hepatocyte cell line.

CONCLUSION

STX17 contributes to mitophagy and maintenance of mitochondrial function in hepatocytes and may be a predictor of graft dysfunction in LDLT patients.

Ferroptosis is induced by lenvatinib through fibroblast growth factor receptor-4 inhibition in hepatocellular carcinoma

The tyrosine kinase inhibitor lenvatinib is used to treat advanced hepatocellular carcinoma (HCC). Ferroptosis is a type of cell death characterized by the iron‐dependent accumulation of lethal lipid reactive oxygen species (ROS). Nuclear factor erythroid‐derived 2‐like 2 (Nrf2) protects HCC cells against ferroptosis. However, the mechanism of lenvatinib‐induced cytotoxicity and the relationships between lenvatinib resistance and Nrf2 are unclear. Thus, we investigated the relationship between lenvatinib and ferroptosis and clarified the involvement of Nrf2 in lenvatinib‐induced cytotoxicity. Cell viability, lipid ROS levels, and protein expression were measured using Hep3B and HuH7 cells treated with lenvatinib or erastin. We examined these variables after silencing fibroblast growth factor receptor‐4 (FGFR4) or Nrf2 and overexpressing‐Nrf2. We immunohistochemically evaluated FGFR4 expression in recurrent lesions after resection and clarified the relationship between FGFR4 expression and lenvatinib efficacy. Lenvatinib suppressed system X_c⁻ (xCT) and glutathione peroxidase 4 (GPX4) expression. Inhibition of the cystine import activity of xCT and GPX4 resulted in the accumulation of lipid ROS. Silencing‐FGFR4 suppressed xCT and GPX4 expression and increased lipid ROS levels. Nrf2‐silenced HCC cells displayed sensitivity to lenvatinib and high lipid ROS levels. In contrast, Nrf2‐overexpressing HCC cells displayed resistance to lenvatinib and low lipid ROS levels. The efficacy of lenvatinib was significantly lower in recurrent HCC lesions with low‐FGFR4 expression than in those with high‐FGFR4 expression. Patients with FGFR4‐positive HCC displayed significantly longer progression‐free survival than those with FGFR4‐negative HCC. Lenvatinib induced ferroptosis by inhibiting FGFR4. Nrf2 is involved in the sensitivity of HCC to lenvatinib.

Assessment of the albumin-bilirubin grade as a prognostic factor in patients with non-small-cell lung cancer receiving anti-PD-1-based therapy

Introduction

The albumin-bilirubin (ALBI) grade is a novel indicator of the liver function. Some studies showed that the ALBI grade was a prognostic and predictive biomarker for the efficacy of chemotherapy in cancer patients. The association between the ALBI grade and outcomes in patients with non-small-cell lung cancer (NSCLC) treated with cancer immunotherapy, however, is poorly understood.

Methods

We retrospectively enrolled 452 patients with advanced or recurrent NSCLC who received anti-programmed cell death protein 1 (PD-1)-based therapy between 2016 and 2019 at three medical centers in Japan. The ALBI score was calculated from albumin and bilirubin measured at the time of treatment initiation and was stratified into three categories, ALBI grade 1-3, with reference to previous reports. We examined the clinical impact of the ALBI grade on the outcomes of NSCLC patients receiving anti-PD-1-based therapy using Kaplan–Meier survival curve analysis with log-rank test and Cox proportional hazards regression analysis.

Results

The classifications of the 452 patients were as follows: grade 1, n = 158 (35.0%); grade 2, n = 271 (60.0%); and grade 3, n = 23 (5.0%). Kaplan–Meier survival curve analysis showed that the ALBI grade was significantly associated with progression-free survival and overall survival. Moreover, Cox regression analysis revealed that the ALBI grade was an independent prognostic factor for progression-free survival and overall survival.

Conclusion

The ALBI grade was an independent prognostic factor for survival in patients with advanced or recurrent NSCLC who receive anti-PD-1-based therapy. These findings should be validated in a prospective study with a larger sample size.

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ALBI grade is calculated from albumin and bilirubin.

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We evaluated the impact of ALBI grade on survival in NSCLC patients receiving immune checkpoint inhibitors.

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ALBI grade was an independent prognostic factor for progression-free survival (PFS) and overall survival (OS).

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ALBI grade effectively stratified PFS and OS in patients with performance status 1-3.

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ALBI grade was significantly associated with PFS and OS, regardless of programmed death ligand-1.

Impact of Nuclear Factor Erythroid 2-Related Factor 2 in Hepatocellular Carcinoma: Cancer Metabolism and Immune Status

We examined phosphorylated nuclear factor erythroid 2–related factor 2 (P‐NRF2) expression in surgically resected primary hepatocellular carcinoma (HCC) and investigated the association of P‐NRF2 expression with clinicopathological features and patient outcome. We also evaluated the relationship among NRF2, cancer metabolism, and programmed death ligand 1 (PD‐L1) expression. In this retrospective study, immunohistochemical staining of P‐NRF2 was performed on the samples of 335 patients who underwent hepatic resection for HCC. Tomography/computed tomography using fluorine‐18 fluorodeoxyglucose was performed, and HCC cell lines after NRF2 knockdown were analyzed by array. We also analyzed the expression of PD‐L1 after hypoxia inducible factor 1α (HIF1A) knockdown in NRF2‐overexpressing HCC cell lines. Samples from 121 patients (36.1%) were positive for P‐NRF2. Positive P‐NRF2 expression was significantly associated with high alpha‐fetoprotein (AFP) expression, a high rate of poor differentiation, and microscopic intrahepatic metastasis. In addition, positive P‐NRF2 expression was an independent predictor for recurrence‐free survival and overall survival. NRF2 regulated glucose transporter 1, hexokinase 2, pyruvate kinase isoenzymes L/R, and phosphoglycerate kinase 1 expression and was related to the maximum standardized uptake value. PD‐L1 protein expression levels were increased through hypoxia‐inducible factor 1α after NRF2 overexpression in HCC cells. Conclusions: Our large cohort study revealed that P‐NRF2 expression in cancer cells was associated with clinical outcome in HCC. Additionally, we found that NRF2 was located upstream of cancer metabolism and tumor immunity.

Molecular and immunological paradigms of hepatocellular carcinoma: Special reference to therapeutic approaches

The development of hepatocellular carcinoma (HCC) is a multistep process with a complex interaction of various genetic backgrounds and the tumor microenvironment. In addition to the development of rational approaches to epidemiologic research, early detection, and diagnosis, considerable progress has been made in systemic treatment with molecular-targeted agents for patients with advanced HCC. Moreover, encouraging reports of recent clinical trials of combination therapy with immune-checkpoint inhibitors (ICIs) has raised high hopes. Each HCC is the result of a unique combination of somatic alterations, including genetic, epigenetic, transcriptomic, and metabolic events, leading to conclusive tumoral heterogeneity. Recent advances in comprehensive genetic analysis have accelerated molecular classification and defined subtypes with specific characteristics, including immune-associated molecular profiles reflecting the immune reactivity in the tumor. In considering the development of therapeutic strategies in combination with immunotherapy, proper interpretation of molecular pathological characterization could lead to effective therapeutic deployment and enable individualization of the management of HCC. Here, we review distinctive molecular alterations in the subtype classification of HCC, current therapies, and representative clinical trials with alternative immune-combination approaches from a molecular pathological point.

Modulation of Nqo1 activity intercepts anoikis resistance and reduces metastatic potential of hepatocellular carcinoma

The processing of intracellular reactive oxygen species (ROS) by nuclear factor erythroid‐derived 2‐like 2 (Nrf2) and NADPH quinone oxidoreductase 1 (Nqo1) is important for tumor metastasis. However, the clinical and biological significance of Nrf2/Nqo1 expression in hepatocellular carcinoma (HCC) remains unclear. We aimed to clarify the clinical importance of Nrf2/Nqo1 expression in HCC and evaluate the association of Nrf2/Nqo1 expression with HCC metastasis. We also evaluated the impact of Nqo1 modulation on HCC metastatic potential. We used spheroids derived from HCC cell lines. In anchorage‐independent culture, HCC cells showed increased ROS, leading to the upregulation of Nrf2/Nqo1. Futile stimulation of Nqo1 by β‐lapachone induces excessive oxidative stress and dramatically increased anoikis sensitivity, finally diminishing the spheroid formation ability, which was far stronger than depletion of Nqo1. We analyzed 117 cases of primary HCC who underwent curative resection. Overexpression of Nrf2/Nqo1 in primary HCC was associated with tumor size, high α‐fetoprotein, and des‐γ‐carboxy‐prothrombin levels. Overexpression of Nrf2/Nqo1 was also associated with multiple intrahepatic recurrences (P = .0073) and was an independent risk factor for poor prognosis (P = .0031). NADPH quinone oxidoreductase 1 plays an important role in anchorage‐independent survival, which is essential for survival for circulation and distant metastasis of HCC cells. These results suggest that targeting Nqo1 activity could be a potential strategy for HCC adjuvant therapy.

Final overall survival results of WJTOG3405, a randomized phase III trial comparing gefitinib versus cisplatin with docetaxel as the first-line treatment for patients with stage IIIB/IV or postoperative recurrent EGFR mutation-positive non-small-cell lung cancer

BACKGROUND

Primary analysis of the phase III study WJTOG 3405 demonstrated superiority of progression-free survival (PFS) for gefitinib (G) in patients treated with the epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) gefitinib compared with cisplatin plus docetaxel (CD) as the first-line treatment of stage IIIB/IV or postoperative recurrent EGFR mutation-positive non-small-cell lung cancer. This report presents final overall survival (OS) data.

PATIENTS AND METHODS

Patients were randomized between G (250 mg/day orally) and cisplatin (80 mg/m2 intravenously) plus docetaxel (60 mg/m2 i.v.), administered every 21 days for three to six cycles. After the exclusion of 5 patients, 172 patients (86 in each group, modified intention-to-treat population) were included in the survival analysis. OS was re-evaluated using updated data (data cutoff, 30 September 2013; median follow-up time 59.1 months). The Kaplan-Meier method and the log-rank test were used for analysis, and hazard ratios (HRs) for death were calculated using the Cox proportional hazards model.

RESULTS

OS events in the G group and CD group were 68 (79.1%) out of 86 and 59 (68.6%) out of 86, respectively. Median survival time for G and CD were 34.9 and 37.3 months, respectively, with an HR of 1.252 [95% confidence interval (CI): 0.883-1.775, P = 0.2070]. Multivariate analysis identified postoperative recurrence and stage IIIB/IV disease as independent prognostic factors, with an HR of 0.459 (95% CI: 0.312-0.673, P < 0.001). Median survival time (postoperative recurrence versus stage IIIB/IV disease) were 44.5 and 27.5 months in the G group and 45.5 and 32.8 months in the CD group, respectively.

CONCLUSION

G did not show OS benefits over CD as the first-line treatment. OS of patients with postoperative recurrence was better than that of stage IIIB/IV disease, even though both groups had metastatic disease.This study was registered with UMIN (University Hospital Medical Information Network in Japan), number 000000539.

Characterization of human pegivirus infection in liver transplantation recipients

Approximately 2% of healthy persons are infected with human pegivirus (HPgV). HPgV is transmitted via vertical, sexual, and blood-borne routes. Recently, the association of HPgV infection with the risk of lymphoma was reported. Here, we examined the prevalence of chronic HPgV infection in liver transplantation (LT) recipients and patients with hepatectomy and the influence of HPgV infection after LT on clinical and perioperative factors. We enrolled 313 LT recipients and 187 patients with hepatectomy who received care at the Kyusyu University Hospital between May 1997 and September 2017. Of the 313 recipients and 187 patients enrolled in this study, 44 recipients (14.1%) and 2 patients (1.1%) had HPgV viremia, respectively. There was no significant association between HPgV infection and LT outcomes. Interestingly, one recipient was infected with HPgV during the peritransplant period, which was likely transmitted via blood transfusion because HPgV RNA was detected from the blood bag transfused to the recipient during LT. We reviewed the available literature on the prevalence HPgV infections in other organ-transplanted patients and whether they impacted clinical outcomes. They also had the higher prevalence of HPgV infection, while it appears to be of low or no consequences. In addition, HPgV infection induced the upregulation of interferon-stimulated gene (ISG) expression in peripheral blood mononuclear cells. LT recipients had higher HPgV viremia compared to patients with hepatectomy. Although HPgV infection was not associated with LT-related outcomes, it induced ISG expression in recipients.

Prognostic significance of inflammatory biomarkers in hepatocellular carcinoma following hepatic resection

Background

Cancer‐related inflammation has been correlated with cancer prognosis. This study evaluated inflammatory biomarkers, including neutrophil‐to‐lymphocyte ratio (NLR), platelet‐to‐lymphocyte ratio (PLR) and lymphocyte‐to‐monocyte ratio (LMR), programmed death ligand (PD‐L) 1 expression, and tumour microenvironment in relation to prognosis and clinicopathological features of patients with hepatocellular carcinoma (HCC) undergoing curative hepatic resection.

Methods

Patients who had liver resection for HCC in 2000–2011 were analysed. Univariable and multivariable analyses were conducted for overall (OS) and recurrence‐free (RFS) survival. Immunohistochemical analyses of PD‐L1, CD8 and CD68 expression were performed. HCC cell lines were evaluated for PD‐L1 expression. A subgroup analysis was conducted to determine patient features, survival and the tumour microenvironment. Results were validated in a cohort of patients with HCC treated surgically in 2012–2016.

Results

Some 281 patients who underwent hepatic resection for HCC were included. Multivariable analysis showed that low LMR was an independent prognostic factor of OS (hazard ratio (HR) 1·59, 95 per cent c.i. 1·00 to 2·41; P = 0·045) and RFS (HR 1·47, 1·05 to 2·04; P = 0·022) after resection. Low preoperative LMR values were correlated with higher α‐fetoprotein values (P < 0·001), larger tumour size (P < 0·001), and high rates of poor differentiation (P = 0·035) and liver cirrhosis (P = 0·008). LMR was significantly lower in PD‐L1‐positive patients than in those with PD‐L1 negativity (P < 0·001). Results were confirmed in the validation cohort. PD‐L1 expression was upregulated in HCC cell lines treated with interferon‐γ and co‐cultured with THP‐1 monocyte cells.

Conclusion

LMR is an independent predictor of survival after hepatic resection in patients with HCC. Modulation of the immune checkpoint pathway in the tumour microenvironment is associated with a low LMR.

Evaluation of the compliance with antiemetic guidelines for prevention of chemotherapy-induced nausea and vomiting in patients with hematologic malignancy

To assess compliance with the Japanese antiemetic guidelines for chemotherapy-induced nausea and vomiting (CINV), the frequencies of CINV occurrence and use of antiemetic rescue medications were examined in patients with hematological malignancy. A total of 40 patients with hematologic malignancy were eligible in this study. This study was performed in the Department of Hematology, Kyushu University Hospital, as a subgroup analysis from a nationwide, multicenter prospective cohort study conducted by the CINV Study Group of Japan. In the patients with hematological malignancy, the guideline compliance rate was 45 %. Five patients (22.7 %) experienced vomiting during the observation period after receiving non-guideline-consistent antiemetic prophylaxis, whereas no patient experienced vomiting after receiving guideline-consistent antiemetic prophylaxis. The study was not sufficiently powered to reach a statistical significance in its frequency of occurrence between the compliance and non-compliance groups. In the entire study period, 8 out of 40 patients required rescue medication, but there was no association between the status of compliance and the antiemetic guidelines. A total of 22 (55.0 %) patients achieved complete response, which was defined as no vomiting and no use of antiemetic rescue medication, during the study period. The rate of compliance with the prophylactic antiemetic treatment guidelines seemed to be low in patients with hematological malignancy, although the status of the guideline compliance did not always influence the antiemetic effects.

PCR Analysis Methods for Detection and Identification of Beer-Spoilage Lactic Acid Bacteria

Polymerase chain reaction (PCR) analysis enables rapid and accurate detection of beer-spoilage lactic acid bacteria (LAB). Hop resistance genes, horA and horC, are utilized as genetic markers to determine the spoilage ability of LAB strains. PCR analysis of horA and horC, combined with multiplex PCR methods of 12 beer-spoilage species, enables simultaneous and comprehensive detection easily and inexpensively.

Liver-enriched transcription factor expression relates to chronic hepatic failure in humans

The mechanisms by which the liver fails in end-stage liver disease remain elusive. Disruption of the transcription factor network in hepatocytes has been suggested to mediate terminal liver failure in animals. However, this hypothesis remains unexplored in human subjects. To study the relevance of transcription factor expression in terminal stages of chronic liver failure in humans, we analyzed the expression of liver-enriched transcription factors (LETFs) hepatocyte nuclear factor (HNF)4α, HNF1α, forkhead box protein A2 (FOXA2), CCAAT/enhancer-binding protein (CEBP)α, and CEBPβ. We then selected downstream genes responsible for some hepatic functions (ornithine transcarbamylase [OTC], cytochrome P450 3A4 [CYP3A4], coagulation factor VII [F7], cadherin 1 [CDH1], phospho-ezrin (Thr567)/radixin (Thr564)/moesin (Thr558) [p-ERM], phospho-myosin light chain [p-MLC], low-density lipoprotein receptor-related protein 1 [LRP1]) in liver tissue from patients at different stages of decompensated liver function based upon Child-Pugh classification, Model for End-Stage Liver Disease score, and degree of inflammatory activity/fibrosis. We first examined differential expression of LETF and determined whether a relationship exists between transcript and protein expression, and liver function. We found HNF4α expression was down-regulated and correlated well with the extent of liver dysfunction (P = 0.001), stage of fibrosis (P = 0.0005), and serum levels of total bilirubin (P = 0.009; r = 0.35), albumin (P < 0.001; r = 0.52), and prothrombin time activity (P = 0.002; r = 0.41). HNF4α expression also correlated with CYP3A4, OTC, and F7 as well as CDH1 RNA levels. The Rho/Rho-associated protein kinase pathways, which have been implicated in the regulation of HNF4α, were also differentially expressed, in concert with LRP1, a reported upstream regulator of RhoA function. Conclusion: HNF4α and other members of the LETFs appear to be important regulators of hepatocyte function in patients with chronic hepatic failure. (Hepatology Communications 2018;2:582-594).