Prognostic value of the lymph node ratio in oropharyngeal carcinoma stratified for HPV-status

OBJECTIVE

Lymph node ratio (LNR) was shown to be a prognostic factor in laryngeal and oral cavity primaries. The purpose of this study was to investigate the impact of the lymph node ratio in oropharyngeal squamous cell carcinoma (OPSCC) with a high incidence of HPV-related disease. Therefore, the role of LNR was evaluated as an additional predictive parameter to the 8th edition of AJCC TNM staging system.

METHODS

From December 2009 to August 2015, patients diagnosed with primary oropharyngeal squamous cell carcinoma were prospectively enrolled. After tumor resection with uni- or bilateral neck dissection, patients with ≥ 1 nodal metastasis (pN+) were eligible for a retrospective LNR analysis.

RESULTS

137 patients underwent tumor resection with uni- or bilateral neck dissection. The proportion of HPV-associated disease was 42%. Most patients (n = 96; 70%) presented with involved neck nodes. In p16-positive OPSCC, the rate of pN + cases was significantly increased compared to p16-negative OPSCC (86% vs. 58%, p = 0.007). Patients with LNR ≤ 10% had a significant better overall survival (OS) and disease-specific survival (DSS). However, when stratified for p16-status, LNR ≤ 10% had a significant impact on OS only for HPV-associated tumors (p = 0.027), whereas LNR of ≤ 10% was not a significant predictor for better OS in p16-negative OPSCC (p = 0.143).

CONCLUSION

The LNR with a cut-off value of 10% serves as an additional prognostic parameter in HPV-related OPSCC and may help to improve risk stratification in combination with the revised AJCC 8th edition TNM classification.

Midkine Controls Arteriogenesis by Regulating the Bioavailability of Vascular Endothelial Growth Factor A and the Expression of Nitric Oxide Synthase 1 and 3

Midkine is a pleiotropic factor, which is involved in angiogenesis. However, its mode of action in this process is still ill defined. The function of midkine in arteriogenesis, the growth of natural bypasses from pre-existing collateral arteries, compensating for the loss of an occluded artery has never been investigated. Arteriogenesis is an inflammatory process, which relies on the proliferation of endothelial cells and smooth muscle cells. We show that midkine deficiency strikingly interferes with the proliferation of endothelial cells in arteriogenesis, thereby interfering with the process of collateral artery growth. We identified midkine to be responsible for increased plasma levels of vascular endothelial growth factor A (VEGFA), necessary and sufficient to promote endothelial cell proliferation in growing collaterals. Mechanistically, we demonstrate that leukocyte domiciled midkine mediates increased plasma levels of VEGFA relevant for upregulation of endothelial nitric oxide synthase 1 and 3, necessary for proper endothelial cell proliferation, and that non-leukocyte domiciled midkine additionally improves vasodilation.

The data provided on the role of midkine in endothelial proliferation are likely to be relevant for both, the process of arteriogenesis and angiogenesis. Moreover, our data might help to estimate the therapeutic effect of clinically applied VEGFA in patients with vascular occlusive diseases.

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Leukocyte domiciled midkine is decisive for collateral endothelial cell proliferation in arteriogenesis.

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Midkine controls the bioavailability of VEGFA mediating endothelial Nos1 and Nos3 expression.

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Nos1 and Nos3, relevant for endothelial cell proliferation, can substitute for each other.

Arteriogenesis is a life and tissue saving process as it compensates for the loss of an occluded artery. Decoding the underlying molecular mechanisms is a prerequisite for the development of novel therapeutic options to treat patients with vascular occlusive diseases. Lautz et al. identified midkine to be responsible for the increased bioavailability of VEGFA during arteriogenesis, necessary and sufficient to promote endothelial cell proliferation. These data might help to estimate the therapeutic effect of clinically applied VEGFA. As the identified mechanisms might also apply for angiogenesis, they are likely to be of broader relevance, e.g. in terms of tumor treatment.

Perivascular Mast Cells Govern Shear Stress-Induced Arteriogenesis by Orchestrating Leukocyte Function

The body has the capacity to compensate for an occluded artery by creating a natural bypass upon increased fluid shear stress. How this mechanical force is translated into collateral artery growth (arteriogenesis) is unresolved. We show that extravasation of neutrophils mediated by the platelet receptor GPIbα and uPA results in Nox2-derived reactive oxygen radicals, which activate perivascular mast cells. These c-kit(+)/CXCR-4(+) cells stimulate arteriogenesis by recruiting additional neutrophils as well as growth-promoting monocytes and T cells. Additionally, mast cells may directly contribute to vascular remodeling and vascular cell proliferation through increased MMP activity and by supplying growth-promoting factors. Boosting mast cell recruitment and activation effectively promotes arteriogenesis, thereby protecting tissue from severe ischemic damage. We thus find that perivascular mast cells are central regulators of shear stress-induced arteriogenesis by orchestrating leukocyte function and growth factor/cytokine release, thus providing a therapeutic target for treatment of vascular occlusive diseases.

Differential effect of long-term drug selection with doxorubicin and vorinostat on neuroblastoma cells with cancer stem cell characteristics

Numerous studies have confirmed that cancer stem cells (CSCs) are more resistant to chemotherapy; however, there is a paucity of data exploring the effect of long-term drug treatment on the CSC sub-population. The purpose of this study was to investigate whether long-term doxorubicin treatment could expand the neuroblastoma cells with CSC characteristics and histone acetylation could affect stemness gene expression during the development of drug resistance. Using n-myc amplified SK-N-Be(2)C and non-n-myc amplified SK-N-SH human neuroblastoma cells, our laboratory generated doxorubicin-resistant cell lines in parallel over 1 year; one cell line intermittently treated with the histone deacetylase inhibitor (HDACi) vorinostat and the other without exposure to HDACi. Cells' sensitivity to chemotherapeutic drugs, the ability to form tumorspheres, and capacity for in vitro invasion were examined. Cell-surface markers and side populations (SPs) were analyzed using flow cytometry. Differentially expressed stemness genes were identified through whole genome analysis and confirmed with real-time PCR. Our results indicated that vorinostat increased the sensitivity of only SK-N-Be(2)C-resistant cells to chemotherapy, made cells lose the ability to form tumorspheres, and reduced in vitro invasion and the SP percentage. CD133 was not enriched in doxorubicin-resistant or vorinostat-treated doxorubicin-resistant cells. Nine stemness-linked genes (ABCB1, ABCC4, LMO2, SOX2, ERCC5, S100A10, IGFBP3, TCF3, and VIM) were downregulated in vorinostat-treated doxorubicin-resistant SK-N-Be(2)C cells relative to doxorubicin-resistant cells. A sub-population of cells with CSC characteristics is enriched during prolonged drug selection of n-myc amplified SK-N-Be(2)C neuroblastoma cells. Vorinostat treatment affects the reversal of drug resistance in SK-N-Be(2)C cells and may be associated with downregulation of stemness gene expression. This work may be valuable for clinicians to design treatment protocols specific for different neuroblastoma patients.

Pericardial effusion and cardiac tamponade in pediatric stem cell transplant recipients

Pericardial effusion and cardiac tamponade is a rarely reported complication following stem cell transplant (SCT). The incidence among pediatric SCT recipients is not well defined. To assess the frequency of clinically significant pericardial effusions, we retrospectively examined clinically significant cardiac effusions at our center. Between January of 1993 and August 2004, clinically significant pericardial effusions were identified in nine of 205 patients (4.4%). The median age at the time of transplant was 9 years (range 0.6-18 years) and seven received an allogeneic transplant. All nine had normal cardiac function prior to transplant. The effusion developed at a median of 30 days (range 18-210 days). All allogeneic recipients had acute or clinically extensive graft-versus-host disease (GVHD) at the time the effusion was diagnosed. Seven patients (78%) required pericardiocentesis or surgical creation of a pericardial window. No patient died as a complication of the effusion or the therapeutic procedures. Clinically significant pericardial effusions are more common than previously reported in pediatric SCT recipients. Acute and chronic GVHD is an associated factor.