NUF2 Expression in Cancer Tissues and Lymph Nodes Suggests Post-Surgery Recurrence of Non-Small Cell Lung Cancer

In non-small cell lung cancer (NSCLC) cases, detecting potential lymph node metastases is essential to determine the indications for sublobar resection or adjuvant therapy. NUF2 is a tumor-specific antigen that is highly expressed in lung cancer tissues. However, the significance of analyzing NUF2 expression in dissected lymph nodes has not yet been studied. Thus, we investigated the association between NUF2 expression in lung cancer tissues and dissected lymph nodes and early recurrence of NSCLC to determine its usefulness as a marker of lymph node micrometastasis. This retrospective study quantified NUF2 expression in the cancer tissues of 88 patients with NSCLC who underwent complete resection using real-time polymerase chain reaction and investigated its relationship with clinicopathological features and prognosis. We also quantified NUF2 RNA expression in mediastinal lymph nodes from 255 patients with pN0 NSCLC who underwent complete resection with lymph node dissection and analyzed its association with prognosis. NUF2 expression in primary tumors was correlated with lymph node metastasis and unfavorable outcomes in terms of poor recurrence-free and cancer-specific survival. In N0 NSCLC cases, high NUF2 expression in mediastinal lymph nodes indicated poor prognosis, especially in lymph node recurrence. NUF2 emerges as a promising marker for predicting lymph node metastatic recurrence, offering potential utility in guiding post-surgical adjuvant therapy for lung cancer or assisting in intraoperative decisions for sublobar resection.

IL-32 production from lung adenocarcinoma cells is potentially involved in immunosuppressive microenvironment

Interleukin 32 (IL-32) is a proinflammatory cytokine secreted from several kinds of cancer cells. In the present study, we investigated the significance of IL-32 in lung adenocarcinoma by immunohistochemistry and bioinformatics analysis. IL-32 was positive in cancer cells of 21 cases (9.2%) of total 228 cases. Increased IL-32 gene expression was linked to worse clinical course in TCGA analysis, however, IL-32 expression in immunohistochemistry was not associated to clinical course in our cohort. It was also found that high IL-32 expression was seen in cases with increased lymphocyte infiltration. In vitro studies indicated that IFN-γ induced gene expression of IL-32 and PD1-ligands in lung adenocarcinoma cell lines. IL-32, especially IL-32β, also induced overexpression of PD1-ligands in human monocyte-derived macrophages. Additionally, Cancer-cell-derived IL-32 was elevated by stimulation with anticancer agents. In conclusion, IL-32 potentially induced by inflammatory conditions and anticancer therapy and contribute to immune escape of cancer cells via development the immunosuppressive microenvironment. IL-32 might be a target molecule for anti-cancer therapy.

PD-L2 overexpression on tumor-associated macrophages is one of the predictors for better prognosis in lung adenocarcinoma

Immunotherapies that target programmed cell death protein 1 (PD-1) signals are standard therapies for advanced-stage lung cancer, and the expression of programmed death-ligand 1 (PD-L1) in cancer tissue predicts immunotherapy efficacy. Although programmed death-ligand 2 (PD-L2) is expressed in cancer cells and macrophages, similar to PD-L1, its significance in lung cancer is unclear. Double immunohistochemistry analyses using anti-PD-L2 and anti-PU.1 antibodies were carried out on tissue array sections from 231 cases of lung adenocarcinoma, and PD-L2 expression in macrophages was evaluated. High PD-L2 expression in macrophages was associated with longer progression-free survival (PFS) and cancer-specific survival (CSS) and observed more often in females, non-heavy smokers, and patients with epidermal growth factor receptor (EGFR) mutations and those at a lower disease stage. Significant correlations were found more frequently in patients with EGFR mutations. Cell culture studies revealed that cancer cell-derived soluble factors induced PD-L2 overexpression in macrophages, suggesting the involvement of the JAK-STAT signaling pathway. The present findings suggest that PD-L2 expression in macrophages predicts PFS and CSS in lung adenocarcinoma without immunotherapy.

The Significance of SPP1 in Lung Cancers and Its Impact as a Marker for Protumor Tumor-Associated Macrophages

Macrophages are a representative cell type in the tumor microenvironment. Macrophages that infiltrate the cancer microenvironment are referred to as tumor-associated macrophages (TAMs). TAMs exhibit protumor functions related to invasion, metastasis, and immunosuppression, and an increased density of TAMs is associated with a poor clinical course in many cancers. Phosphoprotein 1 (SPP1), also known as osteopontin, is a multifunctional secreted phosphorylated glycoprotein. Although SPP1 is produced in a variety of organs, at the cellular level, it is expressed on only a few cell types, such as osteoblasts, fibroblasts, macrophages, dendritic cells, lymphoid cells, and mononuclear cells. SPP1 is also expressed by cancer cells, and previous studies have demonstrated correlations between levels of circulating SPP1 and/or increased SPP1 expression on tumor cells and poor prognosis in many types of cancer. We recently revealed that SPP1 expression on TAMs is correlated with poor prognosis and chemoresistance in lung adenocarcinoma. In this review, we summarize the significance of TAMs in lung cancers and discuss the importance of SPP1 as a new marker for the protumor subpopulation of monocyte-derived TAMs in lung adenocarcinoma. Several studies have shown that the SPP1/CD44 axis contribute to cancer chemoresistance in solid cancers, so the SPP1/CD44 axis may represent one of the most critical mechanisms for cell-to-cell communication between cancer cells and TAMs.

The expression of PD-1 ligand 1 on macrophages and its clinical impacts and mechanisms in lung adenocarcinoma

Programmed cell death-1 (PD-1) and PD-1 ligand 1 (PD-L1) are target molecules for immunotherapy in non-small cell lung cancer. PD-L1 is expressed not only in cancer cells, but also on macrophages, and has been suggested to contribute to macrophage-mediated immune suppression. We examined the clinical significance of PD-L1 expression on macrophages in human lung adenocarcinoma. The mechanism of PD-L1 overexpression on macrophages was investigated by means of cell culture studies and animal studies. The results showed that high PD-L1 expression on macrophages was correlated with the presence of EGFR mutation, a lower cancer grade, and a shorter cancer-specific overall survival. In an in vitro study using lung cancer cell lines and human monocyte-derived macrophages, the conditioned medium from cancer cells was found to up-regulate PD-L1 expression on macrophages via STAT3 activation, and a cytokine array revealed that granulocyte–macrophage colony-stimulating factor (GM-CSF) was a candidate factor that induced PD-L1 expression. Culture studies using recombinant GM-CSF, neutralizing antibody, and inhibitors indicated that PD-L1 overexpression was induced via STAT3 activation by GM-CSF derived from cancer cells. In a murine Lewis lung carcinoma model, anti-GM-CSF therapy inhibited cancer development via the suppression of macrophage infiltration and the promotion of lymphocyte infiltration into cancer tissue; however, the PD-L1 expression on macrophages remained unchanged. PD-L1 overexpression on macrophages via the GM-CSF/STAT3 pathway was suggested to promote cancer progression in lung adenocarcinoma. Cancer cell-derived GM-CSF might be a promising target for anti-lung cancer therapy.

SPP1 Derived from Macrophages Is Associated with a Worse Clinical Course and Chemo-Resistance in Lung Adenocarcinoma

Simple Summary

Osteopontin, also called secreted phosphoprotein 1 (SPP1), is expressed by cancer cells and is known as a poor prognostic factor. Although the production of SPP1 by tumor-associated macrophages (TAMs) has been attracting much attention recently, there have been no studies distinguishing the SPP1 expression of cancer cells and TAMs. In the present study, we demonstrated the following points. (1) Increased SPP1 expression on TAMs is associated with a worse clinical course in EGFR-wild-type adenocarcinoma. (2) SPP1 expression on macrophages is dependent on GM-CSF-mediated macrophage differentiation. (3) Macrophage-derived SPP1 potentially contributed to chemoresistance in lung cancer.

Abstract

Osteopontin, also called secreted phosphoprotein 1 (SPP1), is a multifunctional secreted phosphorylated glycoprotein. SPP1 is also expressed in tumor cells, and many studies demonstrated that a high level of circulating SPP1 is correlated with a poor prognosis in various cancers. SPP1 is expressed not only by tumor cells but also by stromal cells, such as macrophages. However, there have been no studies distinguishing the SPP1 expression of cancer cells and tumor-associated macrophages (TAMs). Thus, in this study, we tried to accurately evaluate the SPP1 expression status on cancer cells and TAMs separately in patients with non-small cell lung cancer by using double immunohistochemistry. We demonstrated that high SPP1 expression on TAMs predicted a poor prognosis in lung adenocarcinoma patients. Additionally, we investigated the expression mechanisms related to SPP1 using human-monocyte-derived macrophages and revealed that the SPP1 expression level increased in macrophage differentiation mediated by granulocyte-macrophage colony-stimulating factor. Furthermore, SPP1 contributed to anti-cancer drug resistance in lung cancer cell lines. In conclusion, SPP1 production on TAMs predicted a poor prognosis in lung adenocarcinoma patients, and TAM-derived SPP1′s involvement in the chemo-resistance of cancer cells was suggested.

Classification of PD-L1 expression in various cancers and macrophages based on immunohistocytological analysis

Programmed death (PD)‐1/PD‐ligand 1 (PD‐L1) antibodies have shown an intense clinical effect in some patients with PD‐L1⁺ tumors, and their applications have rapidly expanded to various cancer types with or without the application of new companion diagnostics (CDx) with a lower cutoff value and inclusion of macrophage evaluation. However, the pathological background explaining the difference in the cutoff value remains unknown. To address this, we evaluated tissue array samples from 231 patients with lung adenocarcinoma, 186 with lung squamous cell carcinoma, and 38 with renal cell carcinoma (RCC) who were not receiving PD‐1/PD‐L1 antibodies to investigate the relationship between PD‐L1 expression on tumor cells and CD8⁺ T‐cell infiltration in tumor tissues. PD‐L1 expression in RCC was clearly lower than that in non–small‐cell lung cancer (NSCLC) tissue, whereas CD8⁺ T‐cell infiltration was low in all cancers. We next analyzed PD‐L1 expression by interferon (α, β, and γ) and LPS stimulation in both macrophages and 41 cancer cell lines derived from various organs and histological types. The PD‐L1 expression patterns were classified into three types, which differed depending on each organ or tissue type. Interestingly, NSCLC cell lines showed highly diverse PD‐L1 expression patterns compared with RCC cell lines. Conversely, PD‐L1 expression was stronger and more prolonged in macrophages than in typical cell lines. Here, we revealed the diversity of the PD‐L1 expression patterns in tumor cells and macrophages, demonstrating the pathological and cytological significance of the transition of cutoff values in PD‐L1 CDx for PD‐1/PD‐L1 antibody administration.

Soluble Factors Involved in Cancer Cell-Macrophage Interaction Promote Breast Cancer Growth

BACKGROUND/AIM

Recent studies have indicated the clinical significance of tumor-associated macrophages (TAMs) in breast cancer; however, the detailed mechanisms of cell-cell interactions between TAMs and cancer cells remain unclear.

MATERIALS AND METHODS

In vitro cell culture studies using human monocyte-derived macrophages and breast cancer cell lines were performed to test which cytokines would be involved in cell-cell interactions between cancer cells and macrophages. In addition, studies using human resected samples and animal breast cancer models were performed to examine the significance of TAMs in cancer development.

RESULTS

Osteopontin, HB-EGF, and IL-6 were suggested to be macrophage-derived growth factors for breast cancer cells. FROUNT inhibitor significantly blocked TAM infiltration and subcutaneous tumor growth in an E0771 mouse breast cancer model.

CONCLUSION

TAMs express growth factors, such as osteopontin, for cancer cells, and targeting of TAM infiltration might be a promising approach for anti-breast cancer therapy.

CD163-positive cancer cells are a predictor of a worse clinical course in lung adenocarcinoma

CD163 is one of the scavenger receptors expressed on macrophages. However, several immunohistochemical studies have demonstrated that CD163 is also detected on cancer cells, and is associated with a poor prognosis. In the present study, we detected CD163 staining on cancer cells in lung adenocarcinoma and squamous cell carcinoma (SCC), and investigated the relationship between CD163 on cancer cells and the clinical prognosis. CD163 staining was seen in 128 of 342 adenocarcinoma cases and 35 of 103 SCC cases. Among the lung adenocarcinoma cases, the progression-free survival and overall survival were significantly shorter in the CD163 high group than the CD163 low group. A similar trend was observed among the SCC cases, but the difference was not statistically significant. Additionally, a higher number of macrophages was detected in areas with CD163-positive cancer cells when compared to areas with CD163-negative cancer cells. In summary, we found that CD163-positive cancer cells are a predictor of a worse clinical course in lung adenocarcinoma and SCC.

Clinical impact of TROP2 in non-small lung cancers and its correlation with abnormal p53 nuclear accumulation

Tumor-associated calcium signal transducer 2 (TROP2) is a cell-surface glycoprotein involved in the high malignant potential of several cancers. Antibody-drug conjugates that target TROP2 represent a promising approach for the treatment of TROP2-expressing cancers including lung cancer and breast cancer. TROP2 expression was tested by immunohistochemistry in lung adenocarcinoma (ADC) and squamous cell carcinoma samples, and its correlation with clinicopathological factors, including survival rate and p53 mutation, was statistically analyzed. We found that increased TROP2 expression was significantly associated with a poor clinical course in patients with ADC, but not in patients with squamous cell carcinoma. A more significant association with poor outcome was seen in ADC cases with a high histological grade as well as those without the epidermal growth factor receptor (EGFR) mutation. A significant correlation between TROP2 expression and abnormal p53 nuclear accumulation/expression was also found in ADC. In the present study, we discovered a significant correlation between TROP2 expression and p53 mutation in ADC, and that TROP2 expression was a prognostic factor in ADC cases with a high histological grade as well as those without the EGFR mutation. Signals mediated by mutated p53 might influence TROP2 expression in ADC.

Accurate expression of PD-L1/L2 in lung adenocarcinoma cells: A retrospective study by double immunohistochemistry

The percentage of programmed death ligand 1 (PD‐L1) positivity in cancer cells, named as the tumor proportion score, is considered to be a predictive biomarker for anti‐PD‐1/PD‐L1 therapy in lung cancer. PD‐L1 is expressed on not only cancer cells but also on immune cells, including macrophages. Although previous studies related to PD‐L1/2 expression in cancer tissues have been generally based on single immunohistochemistry (IHC), in the present study, we attempted to evaluate accurate PD‐L1/2 expression in cancer cells in lung adenocarcinoma cells using double IHC to also evaluate macrophages. Of the 231 patients, PD‐L1 expression was negative in 169 patients (73.2%), 1%‐49% positive in 47 patients (20.3%), and ≥50% positive in 15 patients (6.5%). Interestingly, PD‐L1 positivity was decreased when using double IHC compared with the estimation by single IHC. High PD‐L1 expression was associated with high‐grade cancer cells and in higher stage cancer. PD‐L2 was negative in 109 patients (47.2%), 1%‐49% positive in 50 patients (21.6%), and ≥50% positive in 72 patients (31.2%). The number of PD‐L2‐positive patients was increased in cases that had an epidermal growth factor receptor (EGFR) mutation and in lower stage cancer. Thirty‐five patients (15.2%) were positive for both PD‐L1 and PD‐L2, whereas 81 patients (35.1%) were negative for both PD‐L1 and PD‐L2. Log‐rank analysis showed that progression‐free survival and overall survival were significantly the longest in the PD‐L1‐negative and PD‐L2‐positive groups (P < .0001 and P = .0120). We observed lower PD‐L1 or PD‐L2 expression in lung adenocarcinoma than previously reported. Double IHC for macrophages may help clinicians to evaluate PD‐L1 or PD‐L2 expression specifically in cancer cells.

Clinical outcomes of percutaneous radiofrequency ablation for small renal cancer

Partial nephrectomy is the treatment of choice for small renal cell carcinoma (RCC) from the perspective of cancer management and renal function. However, when patients with RCC are of advanced age, exhibit severe comorbidities, including cardiovascular and pulmonary diseases, or have hereditary RCC, ablative therapies, including radiofrequency ablation (RFA) and cryoablation are useful treatment options. In the present study, the clinical outcomes of percutaneous RFA for treating small RCC were evaluated. Between December 2005 and March 2015, 40 patients (41 renal tumors in total) underwent RFA and a total of 50 sessions of RFA were performed. The average tumor size was 2.5 cm. A total of 18 tumors were exophytic and 23 were parenchymal. Of the 41 tumors, 85.4% were completely ablated by initial RFA and the rate of complete ablation following reablation for residual viable lesions was 95.1%. Local recurrence-free survival following complete ablation was 84.2% at 3 years. A patient with a 4.7 cm RCC tumor rapidly progressed following four RFA treatments until complete ablation was achieved. The metastasis-free survival rate following initial RFA was 95.7% at 3 years. The RCC-specific survival was 100% (mean follow-up, 38 months). Adverse events occurred in five sessions (10%); however, only 1 patient with arteriovenous fistula required intervention (transarterial embolization). The mean hospital stay following RFA was 3.2 days. The mean decrease in estimated glomerular filtration rate following RFA was 2.7%. The results of the present study indicate that percutaneous RFA was an effective treatment for small RCCs with respect to management of cancer, minimal invasiveness and minimal loss of renal function, particularly in patients for whom surgery would be a high risk and those at increased risk of deterioration of renal function.

Synchronous Multiple Lung Adenocarcinomas: Estrogen Concentration in Peripheral Lung

BACKGROUND

The detection rate of synchronous multiple lung adenocarcinomas (SMLA), which display multiple ground glass opacity nodules in the peripheral lung, is increasing due to advances in high resolution computed tomography. The backgrounds of multicentric development of adenocarcinoma are unknown. In this study, we quantitated estrogen concentration in the peripheral lungs of postmenopausal female patients with SMLA.

METHODS

The tissue concentration of estrogens (estrone [E1] and estdadiol [E2]) in the noncancerous peripheral lung were measured with liquid chromatography/electrospray tandem mass spectrometry in postmenopausal female patients with lung adenocarcinoma. The expression levels of CYP19A1 in the normal lung were also quantitated with real-time PCR. Thirty patients with SMLA and 79 cases of control patients with single lung adenocarcinoma were analyzed.

RESULTS

The concentrations of E1 and E2 in the noncancerous tissue were significantly higher in SMLA cases than control cases (P = 0.004 and P = 0.02, respectively). The minor allele (A) of single nucleotide polymorphism rs3764221 were significantly associated with higher concentration of E1 and E2 (P = 0.002 and P = 0.01, respectively) and higher CYP19A1 mRNA expression (P = 0.03).

CONCLUSION

The tissue estrogen concentration of peripheral lung was significantly higher in SMLA than control cases. The high concentration of estrogen may be one of the causes of multicentric development of peripheral lung adenocarcinomas.