Increased Osteopontin-Positive Macrophage Expression in Colorectal Cancer Stroma with Synchronous Liver Metastasis

New Angiogenic Regulators Produced by TAMs: Perspective for Targeting Tumor Angiogenesis

Simple Summary

Since the targeting of a single pro-angiogenic factor fails to improve oncological disease outcome, significant efforts have been made to identify new pro-angiogenic factors that could compensate for the deficiency of current therapy or act independently as single drugs. Our review aims to present the state-of-the art for well-known and recently described factors produced by macrophages that induce and regulate angiogenesis. A number of positive and negative regulators of angiogenesis in the tumor microenvironment are produced by tumor-associated macrophages (TAMs). Accumulating evidence has indicated that, apart from the well-known angiogenic factors, there are plenty of novel angiogenesis-regulating proteins that belong to different classes. We summarize the data regarding the direct or indirect mechanisms of the interaction of these factors with endothelial cells during angiogenesis. We highlight the recent findings that explain the limitations in the efficiency of current anti-angiogenic therapy approaches.

Abstract

Angiogenesis is crucial to the supply of a growing tumor with nutrition and oxygen. Inhibition of angiogenesis is one of the main treatment strategies for colorectal, lung, breast, renal, and other solid cancers. However, currently applied drugs that target VEGF or receptor tyrosine kinases have limited efficiency, which raises a question concerning the mechanism of patient resistance to the already developed drugs. Tumor-associated macrophages (TAMs) were identified in the animal tumor models as a key inducer of the angiogenic switch. TAMs represent a potent source not only for VEGF, but also for a number of other pro-angiogenic factors. Our review provides information about the activity of secreted regulators of angiogenesis produced by TAMs. They include members of SEMA and S100A families, chitinase-like proteins, osteopontin, and SPARC. The COX-2, Tie2, and other factors that control the pro-angiogenic activity of TAMs are also discussed. We highlight how these recent findings explain the limitations in the efficiency of current anti-angiogenic therapy. Additionally, we describe genetic and posttranscriptional mechanisms that control the expression of factors regulating angiogenesis. Finally, we present prospects for the complex targeting of the pro-angiogenic activity of TAMs.

Geriatric nutritional risk index as a prognostic marker of pTNM-stage I and II esophageal squamous cell carcinoma after curative resection

The geriatric nutritional risk index (GNRI) is associated with mortality in several malignancies. We retrospectively analyzed whether the GNRI can predict long-term outcomes in 191 patients with esophageal squamous cell carcinoma (ESCC) after curative esophagectomies by evaluating their cancer-specific survival (CSS). In multivariate analyses, serum albumin (hazard ratio [HR], 2.498; p = 0.0043), GNRI (HR, 1.941; p = 0.0181), pathological tumor-node-metastasis (pTNM) stage (HR, 3.884; p < 0.0001), and tumor differentiation (HR, 2.307; p = 0.0066) were independent prognostic factors for CSS.

In pTNM stage I, multivariate analysis identified C-reactive protein (HR, 7.172; p = 0.0483) and GNRI (HR, 5.579; p = 0.0291) as independent prognostic factors for CSS. In univariate analyses in pTNM stages II and III, only low GNRI (p = 0.0095) and low serum albumin levels (p = 0.0119), respectively, were significantly associated with worse CSS. In patients with low GNRI, CSS was significantly worse than in those with normal GNRI (p = 0.0011), especially in pTNM stages I (p = 0.0044) and II (p = 0.0036) groups, but not in stage III group (p = 0.5099).

Preoperative GNRI may sort patients into low- or high-risk groups for shorter CSS, especially in those with pTNM stage I and II ESCC.

Chemotherapy-generated cell debris stimulates colon carcinoma tumor growth via osteopontin

Colon cancer recurrence after therapy, such as 5-fluorouracil (5-FU), remains a challenge in the clinical setting. Chemotherapy reduces tumor burden by inducing cell death; however, the resulting dead tumor cells, or debris, may paradoxically stimulate angiogenesis, inflammation, and tumor growth. Here, we demonstrate that 5-FU–generated colon carcinoma debris stimulates the growth of a subthreshold inoculum of living tumor cells in subcutaneous and orthotopic models. Debris triggered the release of osteopontin (OPN) by tumor cells and host macrophages. Both coinjection of debris and systemic treatment with 5-FU increased plasma OPN levels in tumor-bearing mice. RNA expression levels of secreted phosphoprotein 1, the gene that encodes OPN, correlate with poor prognosis in patients with colorectal cancer and are elevated in chemotherapy-treated patients who experience tumor recurrence vs. no recurrence. Pharmacologic and genetic ablation of OPN inhibited debris-stimulated tumor growth. Systemic treatment with a combination of a neutralizing OPN antibody and 5-FU dramatically inhibited tumor growth. These results demonstrate a novel mechanism of tumor progression mediated by OPN released in response to chemotherapy-generated tumor cell debris. Neutralization of debris-stimulated OPN represents a potential therapeutic strategy to overcome the inherent limitation of cytotoxic therapies as a result of the generation of cell debris.—Chang, J., Bhasin, S. S., Bielenberg, D. R., Sukhatme, V. P., Bhasin, M., Huang, S., Kieran, M. W., Panigrahy, D. Chemotherapy-generated cell debris stimulates colon carcinoma tumor growth via osteopontin.

Osteopontin-integrin interaction as a novel molecular target for antibody-mediated immunotherapy in adult T-cell leukemia

Background

Adult T-cell leukemia (ATL) is a CD4⁺ T-cell neoplasm with a poor prognosis. A previous study has shown that there is a strong correlation between the secreted matricellular protein osteopontin (OPN) level and disease severity in ATL patients. Here, we investigated the role of OPN in ATL pathogenesis and the possible application of anti-OPN monoclonal antibody (mAb) for ATL immunotherapy in NOD/Shi-scid,IL-2Rg^null (NOG) mice.

Results

Subcutaneous inoculation of ATL cell lines into NOG mice increased the plasma level of OPN, which significantly correlated with metastasis of the inoculated cells and survival time. Administration of an SVVYGLR motif-recognizing anti-OPN mAb resulted in inhibition not only of tumor growth but also of tumor invasion and metastasis. The number of fibroblast activating protein-positive fibroblasts was also reduced by this mAb. We then co-inoculated mouse embryonic fibroblasts (MEFs) isolated from wild-type (WT) or OPN knockout mice together with ATL-derived TL-OmI cells into the NOG mice. The mice co-inoculated with WT MEFs displayed a significant decrease in survival relative to those injected with TL-OmI cells alone and the absence of OPN in MEFs markedly improved the survival rate of TL-OmI-inoculated mice. In addition, tumor volume and metastasis were also reduced in the absence of OPN.

Conclusion

We showed that the xenograft NOG mice model can be a useful system for assessment of the physiological role of OPN in ATL pathogenesis. Using this xenograft model, we found that fibroblast-derived OPN was involved in tumor growth and metastasis, and that this tumor growth and metastasis was significantly suppressed by administration of the anti-OPN mAbs. Our findings will lead to a novel mAb-mediated immunotherapeutic strategy targeting against the interaction of OPN with integrins on the tumor of ATL patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12977-015-0225-x) contains supplementary material, which is available to authorized users.

Osteopontin-expressing macrophages in non-small cell lung cancer predict survival

BACKGROUND

Tumor-associated macrophages (TAMs) are a major component of leukocyte infiltration in the tumor microenvironment. Osteopontin is related to tumor metastasis and proliferation. Osteopontin is expressed not only by tumor cells but also by TAMs. The purpose of the current study was to assess the prognostic significance of osteopontin expressed by TAMs (TOPN) in patients with non-small cell lung cancer.

METHODS

Tissue microarray was used to detect the expression of TOPN, TAMs, and microvascular density in 159 patients with non-small cell lung cancer undergoing complete pulmonary resection in our hospital between 2003 and 2006. The correlations between TOPN, TAMs, and clinicopathologic data were analyzed with χ(2) tests. Quantitation of TAMs or TOPN and microvascular density analyses was performed using Bonferroni correction and the Student's t test. The prognostic value of TOPN was evaluated by univariate Kaplan-Meier survival analysis and multivariate Cox proportional hazard model analysis.

RESULTS

In the recurrence and metastasis group, microvascular density was higher than that in the control group (14.4 ± 1.06 versus 8.9 ± 1.02; p = 0.0002). In the TOPN-positive group, microvascular density was increased compared with that in the TOPN-negative group (14.3 ± 1.37 versus 10.7 ± 0.91; p = 0.0273). Osteopontin expressed by TAMs was an independent predictor for overall survival (p = 0.017) and disease-free survival (p < 0.001), especially for stage I non-small cell lung cancer. The 6-year overall and disease-free survival rates in TOPN-positive patients were 22.64% and 16.98%, respectively, which were significantly lower than those of TOPN-negative patients (50.00% and 39.62%, respectively).

CONCLUSIONS

Osteopontin expressed by TAMs is a valuable independent predictor of tumor recurrence and survival in patients with non-small cell lung cancer.

Increased osteopontin expression is associated with progression from vulvar precancerous lesions to vulvar squamous cell carcinoma

PURPOSE

Vulvar squamous cell carcinoma (VSCC) contributes to about 3-5% of all gynecological cancers. Vulvar intraepithelial neoplasia (VIN) and vulvar lichen sclerosus (VLS) are regarded as precancerous lesions. Early detection and treatment of precancerous lesions may prevent development of VSCC. Osteopontin (OPN) has been shown to be involved in many physiological and pathological processes, such as tumor progression, by promoting cancer cell invasion and metastasis. As a result of these findings, OPN has been described as a potential marker for tumor progression in some malignancies. In this study, we investigated the expression of OPN in vulvar tissue specimens and compared its expression between different histopathological grades.

METHODS

In the present study, the expression patterns of OPN in 80 paraffin-embedded tissue specimens, including 25 VSCC samples, 21 VIN lesions and 21 VLS, in addition to 13 normal vulvar samples, were examined by the immunohistochemical method and chromogenic in situ hybridization.

RESULTS

The intensity of OPN expression steadily increased according to the pathological grades. In addition, OPN staining was found in the extracellular matrix in VSCC.

CONCLUSIONS

Expression levels of OPN increased from VLS and VIN to VSCC, and steadily increased with the pathological stage of VSCC. Our results suggest that OPN may be associated with the progression of VSCC.

Reciprocal interactions between tumor-associated macrophages and CD44-positive cancer cells via osteopontin/CD44 promote tumorigenicity in colorectal cancer

PURPOSE

CD44 is of functional importance for tumor initiation and progression in colorectal cancer, but how this molecule benefits cancer cells from the tumor microenvironment, especially tumor-associated macrophages (TAM), remains poorly defined.

EXPERIMENTAL DESIGN

In vivo tumorigenic assays were conducted to assess the role of murine TAMs in the tumorigenesis of human colorectal cancer cells. Both in vitro and in vivo osteopontin (OPN) expression levels in TAMs were examined by immunohistochemistry, quantitative PCR, and Western blotting. Soft agar colony formation assays were used to estimate the clonogenicity of colorectal cancer cells that had received different treatments. The relationships between the expression levels of OPN, CD44v6, and CD68 and clinical prognosis were evaluated by tissue microarray analysis.

RESULTS

We found that macrophages, when coinjected or cocultured with CD44-positive colorectal cancer cells, were able to produce higher levels of OPN, which in turn facilitated the tumorigenicity and clonogenicity of the colorectal cancer cells. The knockdown of CD44 or treatment with blocking antibodies to CD44 attenuated OPN secretion. OPN, through binding to its receptor CD44, activated c-jun-NH(2)-kinase signaling and promoted the clonogenicity of colorectal cancer cells. Moreover, tissue microarray data have shown that OPN expression, in combination with CD44v6, has a negative correlation with colorectal cancer patient survival.

CONCLUSIONS

These results suggest that the OPN-CD44 interaction is important for colorectal cancer progression and could serve as a potential therapeutic target for the treatment of colorectal cancer.

Osteopontin Induced by Macrophages Contribute to Metachronous Liver Metastases in Colorectal Cancer

Even after radical surgery for stage II and stage III colorectal cancer, metachronous liver metastasis is frequently observed. The aim of this study was to identify the risk of metachronous liver metastasis with retrospective clinicopathological study. Immunohistochemistry was performed to evaluate the expression of Osteopontin (OPN), CD-68, and CD105 in 41 cases of stage II and stage III colorectal cancer tissue. Stage II and stage III colorectal cancer patients who had undergone R0 resection were classified into two groups: with metachronous liver metastasis (m-LM; n = 17) and without liver metastases (control; n = 24). Additionally, double-immunofluorescence staining was performed using antibodies to OPN and CD68. OPN-positive cells were frequently colocalized with CD68 immunoreactivity. OPN and microvascular density expression in the central area were significantly higher in the m-LM (OPN; control 4.3 ± 0.56, m-LV 10.8 ± 1.48, P < 0.05; microvascular density control 18.5 ± 2.86, m-LV 31.4 ± 4.39, P < 0.05), while CD68 expression in the invasive margin was significantly higher in the control group (control 98.9 ± 7.31, m-LV 28.2 ± 3.18, P < 0.05). These results suggest that the risk of metachronous liver metastasis could be well predicted by immunohistochemical staining of OPN in the central areas, and CD68 in the invasive margins of tumors.

The role of tumour stroma in colorectal cancer invasion and metastasis

Colorectal cancer (CRC) is a major cause of mortality in western society with a 5-year survival of approximately 50%. Metastasis to the liver and lungs is the principal cause of death and occurs in up to 25% of patients at presentation. Despite advances in available techniques for treating metastases, the majority of patients remain incurable and existing adjuvant therapies such as chemotherapy are only of limited effectiveness. Understanding the molecular mechanisms underlying the metastatic process may allow us to identify those at greatest risk of recurrence and discover new tumour targets to prevent disease progression. It is now apparent that tumour stroma plays an important role in promoting tumour progression. A pronounced desmoplastic reaction was associated with a reduced immune response and has been shown to be an independent poor prognostic indicator in CRC and cancer recurrence. Determining the cause(s) and effect(s) of this stromal response will further our understanding of tumour cell/stromal interactions, and will help us identify prognostic indicators for patients with CRC. This will not only allow us to target our existing treatments more effectively, we also aim to identify novel and more specific therapeutic targets for the treatment of CRC which will add to our current therapeutic options.

Immune maintenance of self in morphostasis of distinct tissues, tumour growth and regenerative medicine

Morphostasis (tissue homeostasis) is a complex process consisting of three circumstances: (1) tissue renewal from stem cells, (2) preservation of tissue cells in a proper differentiated state and (3) maintenance of tissue quantity. This can be executed by a tissue control system (TCS) consisting of vascular pericytes, immune system-related components--monocyte-derived cells (MDC), T cells and immunoglobulins and autonomic innervation. Morphostasis is established epigenetically, during the critical developmental period corresponding to the morphogenetic immune adaptation. Subsequently, the tissues are maintained in a state of differentiation reached during the adaptation by a 'stop effect' of MDC influencing markers of differentiating tissue cells and presenting self-antigens to T cells. Retardation or acceleration of certain tissue differentiation during adaptation results in its persistent functional immaturity or premature ageing. The tissues being absent during adaptation, like ovarian corpus luteum, are handled as a 'graft.' Morphostasis is altered with age advancement, because of the degenerative changes of the immune system. That is why the ageing of individuals and increased incidence of neoplasia and degenerative diseases occur. Hybridization of tumour stem cells with normal tissue cells causes an augmentation of neoplasia by host pericytes and MDC stimulating a 'regeneration' of depleted functional cells. Degenerative diseases are associated with apoptosis. If we are able to change morphostasis in particular tissue, we may disrupt apoptotic process of the cell. An ability to manage the 'stop effect' of MDC may provide treatment for early post-natal tissue disorders, improve regenerative medicine and delay physical, mental and hormonal ageing.