Natural killer cell response to regional lymph node metastases

Progression of Metastasis through Lymphatic System

Lymph nodes are the most common sites of metastasis in cancer patients. Nodal disease status provides great prognostic power, but how lymph node metastases should be treated is under debate. Thus, it is important to understand the mechanisms by which lymph node metastases progress and how they can be targeted to provide therapeutic benefits. In this review, we focus on delineating the process of cancer cell migration to and through lymphatic vessels, survival in draining lymph nodes and further spread to other distant organs. In addition, emerging molecular targets and potential strategies to inhibit lymph node metastasis are discussed.

Producing Capabilities of Interferon-gamma and Interleukin-10 in Peripheral Blood from Oral Squamous Cell Carcinoma Patients

In order to evaluate the Th1 and Th2 responses of Oral Squamous Cell Carcinoma (OSCC) patients, we investigated the cytokine producing capability of peripheral blood (PB), and compared it with clinicopathological appearances of OSCC patients. The production of a Th1-type cytokine, interferon (IFN)-γ, from lipopolysaccharide (LPS)-stimulated PB correlated positively with the frequency of lymph node metastasis. We also investigated the production of a Th2-type cytokine, IL-10, however, no significant correlation was observed with the clinicopathological appearances. Our results suggested that the IFN-γ producing capability was specifically regulated and dependent on the regional metastatic potencies of OSCCs.

Interferon alpha2b augments suppressed immune functions in tobacco-related head and neck squamous cell carcinoma patients by modulating cytokine signaling

We have examined the role of interferon alpha2b (IFNalpha2b) in augmentation of the suppressed immune functions and cytotoxicity of tobacco-related head and neck squamous cell carcinoma (HNSCC) patients. The suppressed killing activity of PBMC of HNSCC patients towards KB, MCF7 and K562 cell lines could be restored by in vitro treatment of PBMC with IFNalpha2b, as detected by LDH release assay. HNSCC patients with cisplatin + 5FU + IFNalpha2b treatment showed greater cytotoxic efficacy than corresponding pretreatment values. Analysis of culture supernatant of HNSCC-PBMC by ELISA revealed the lower secretion of IL-12 and IFNgamma with increased level of IL-4 and IL-10. This altered Th1/Th2 status was rectified after in vitro and in vivo IFNalpha2b stimulation. Increased secretion of monocyte derived IL-12 was observed after IFNalpha2b treatment that can enhance the IFNgamma release, a key regulator for cytotoxicity. IFNalpha2b stimulated enhancement of NK cells may be the source of greater amount of IFNgamma. IFNalpha2b activated STAT1 and STAT4 signaling is observed to be involved in the regulation and maintenance of cytokine milieu. We conclude that IFNalpha2b may be effective as a tool for adjuvant therapy along with conventional therapies to overcome the immunosuppression in HNSCC patients.

Development of a new in vivo model for head and neck cancer

We have developed an improved model for studying in vivo nonsurgical treatment of head and neck cancer. In situ oral cavity implantation has been documented, but its natural history is not defined. In light of this, an improved model is described. Forty-two nude mice had tumor cells from one of two established laryngeal squamous cell carcinoma cell lines implanted into the floor of the mouth. The tumor mass was measured and followed. When the tumor burden was great enough to cause cachexia, the animals were killed and submitted for microscopic examination. Pulmonary metastases were noted in 44%, bone invasion in 80%, angioinvasion in 76%, and soft tissue invasion in 96% of the animals. Growth characteristics in the head and neck have not been documented in previous models. Our model not only exhibits the locally invasive activity typically associated with malignant neoplasms, but also closely parallels the results of clinical studies examining the percent of end stage patients and autopsies with pulmonary metastases. Therefore, this model should open the way for more meaningful in vivo studies of nonsurgical treatment modalities for both local and metastatic tumor foci in head and neck cancer.

Pharyngeal carcinoma and natural killer cell activity

An evaluation of natural killer cell activity was performed in 42 patients with pharyngeal carcinoma. Compared with age- and sex-matched control subjects, the cancer patients expressed significantly lower cytotoxicity against K562 target cells (68 +/- 8 lytic units versus 99 +/- 8 lytic units, p less than 0.01), with 52 percent of the patients expressing deficient activity (below 1 standard deviation of the mean activity of the control population). The probability of deficient activity was greater in these patients than observed in patients with cancer of other head and neck sites. Although natural killer cell activity was lower in patients who drank alcohol or had nodal metastases, no single clinical factor was predictive of deficient cytotoxic response. Prospective longitudinal evaluation (mean = 12 months) of these pharyngeal cancer patients demonstrated that deficient natural killer cell activity measured before treatment identified a population with a significantly increased risk for the development of distant metastases. Distant metastases developed in 7 of 18 patients (39 percent) with deficient natural killer cell activity. In contrast, none of the 16 patients with normal natural killer cell function had evidence of distant disease at last follow-up (p less than 0.01). Deficient natural killer cell activity exists in patients with pharyngeal cancer and is an independent marker for the subsequent development of distant metastases.