Optimism, social support, and adjustment in African American women with breast cancer.

Past studies show that optimism and social support are associated with better adjustment following breast cancer treatment. Most studies have examined these relationships in predominantly non-Hispanic White samples. The present study included 77 African American women treated for nonmetastatic breast cancer. Women completed measures of optimism, social support, and adjustment within 10-months of surgical treatment. In contrast to past studies, social support did not mediate the relationship between optimism and adjustment in this sample. Instead, social support was a moderator of the optimism-adjustment relationship, as it buffered the negative impact of low optimism on psychological distress, well-being, and psychosocial functioning. Women with high levels of social support experienced better adjustment even when optimism was low. In contrast, among women with high levels of optimism, increasing social support did not provide an added benefit. These data suggest that perceived social support is an important resource for women with low optimism.

Melanoma cells exhibit variable signal transducer and activator of transcription 1 phosphorylation and a reduced response to IFN-alpha compared with immune effector cells.

PURPOSE: IFN-alpha is administered to melanoma patients and its endogenous production is essential for immune-mediated tumor recognition. We hypothesized that a reduced capacity for signal transducer and activator of transcription (STAT) 1 activation allows melanoma cells to evade the direct actions of IFN-alpha. EXPERIMENTAL DESIGN: Tyr(701)-phosphorylated STAT1 (P-STAT1) was measured by flow cytometry in IFN-alpha-stimulated human melanoma cell lines, melanoma cells derived from patient tumors, and peripheral blood mononuclear cells (PBMC). Expression of other Janus-activated kinase (Jak)-STAT intermediates (STAT1, STAT2, Jak1, tyrosine kinase 2, IFN-alpha receptor, STAT3, and STAT5) was evaluated by flow cytometry, immunoblot, or immunohistochemistry. RESULTS: Significant variability in P-STAT1 was observed in human melanoma cell lines following IFN-alpha treatment (P < 0.05) and IFN-alpha-induced P-STAT1 correlated with the antiproliferative effects of IFN-alpha (P = 0.042). Reduced formation of P-STAT1 was not explained by loss of Jak-STAT proteins or enhanced STAT5 signaling as reported previously. Basal levels of P-STAT3 were inversely correlated with IFN-alpha-induced P-STAT1 in cell lines (P = 0.013). IFN-alpha-induced formation of P-STAT1 was also variable in melanoma cells derived from patient tumors; however, no relationship between P-STAT3 and IFN-alpha-induced P-STAT1 was evident. Because IFN-alpha acts on both tumor and immune cells, we examined the ability of IFN-alpha to induce P-STAT1 in patient-derived melanoma cells and PBMCs. IFN-alpha induced significantly lower levels of P-STAT1 in melanoma cells compared with matched PBMCs (P = 0.046). Melanoma cells and human melanocytes required 10-fold higher IFN-alpha doses to exert P-STAT1 levels comparable with PBMCs. CONCLUSIONS: Melanoma cells are variable in their IFN-alpha responsiveness, and cells of the melanocytic lineage exhibit a lower capacity for IFN-alpha-induced Jak-STAT signaling compared with immune cells.

Interferon alpha and CPG oligodeoxynucleotides elicit additive immunostimulatory and antitumor effects.

BACKGROUND: We hypothesized that interferon alpha (IFN-alpha) and unmethylated cytosine-phosphothioate-guanine (CpG)-rich oligodexoynucleotides (CpG ODNs) would elicit potent antitumor activity due to the ability of this treatment combination to activate complimentary signal transduction intermediates. METHODS: Peripheral blood mononuclear cells treated with CpG ODNs, IFN-alpha, or both agents combined were evaluated for cytotoxicity against human melanoma cells, Jak-STAT signal transduction by flow cytometry, and ISG-15 gene expression by real-time polymerase chain reaction. The effects of CpG ODNs and IFN-alpha were evaluated in murine models of melanoma in wild-type, IFN-gamma-deficient, and STAT1-deficient mice. Negative controls in all experiments included treatment with control ODN or phosphate-buffered saline. RESULTS: Treatment of peripheral blood mononuclear cells with a combination of CpG ODNs and IFN-alpha resulted in enhanced cytotoxicity, activation of natural killer cells, IFN-alpha-induced STAT1 phosphorylation, and transcription levels of ISG-15. These immunostimulatory effects of CpG ODNs were associated with increased expression of STAT1 and STAT2 proteins. Administration of CpG ODNs plus IFN-alpha elicited superior antitumor activity in a murine model of B16 melanoma compared with either agent alone. The antitumor properties of CpG ODNs were dependent on STAT1-mediated signal transduction within the host but independent of endogenously produced IFN-gamma. CONCLUSIONS: CpG ODNs represent potent immune stimulants that elicit antitumor effects through STAT1-mediated signal transduction.

Multiparametric flow cytometric analysis of inter-patient variation in STAT1 phosphorylation following interferon Alfa immunotherapy.

BACKGROUND: Regulation of gene expression by signal transducer and activator of transcription 1 (STAT1) within host tissues mediates the antitumor effects of interferon alfa (IFN alpha). We used a novel flow cytometric assay to examine phosphorylation-mediated activation of STAT1 within immune effector cell subsets following in vitro or in vivo IFN alpha treatments. METHODS: Peripheral blood mononuclear cells (PBMCs) isolated from healthy donors (n = 17) or melanoma patients (n = 19) were treated in vitro with interferon alfa-2b (IFN alpha-2b) or phosphate-buffered saline (PBS) and subjected to multiparametric flow cytometry to measure the levels of phosphorylated STAT1 (P-STAT1) within immune cell subsets. We similarly analyzed PBMCs isolated from melanoma patients before and 1 hour after immunotherapy with IFN alpha-2b. All statistical tests were two-sided. RESULTS: P-STAT1 levels in all major immune cell subsets increased within 15 minutes of in vitro IFN alpha-2b treatment of PBMCs; the increase was most pronounced in T lymphocytes and monocytes. Relatively low doses of IFN alpha-2b (i.e., 10(2)-10(3) IU/mL) induced maximal STAT1 activation in vitro. Compared with melanoma patients, healthy donors had higher basal levels of P-STAT1 (specific fluorescence [Fsp]; i.e., Fsp(PBS), the level of P-STAT1 in PBS-treated cells) in total PBMCs, natural killer (NK) cells, and T cells (mean Fsp(PBS) in total PBMCs: 5.5 in healthy donors versus 1.6 in patients, difference = 3.9, 95% confidence interval [CI] = 1.4 to 6.5, P =.004; mean Fsp(PBS) in NK cells: 4.6 in healthy donors versus 0.9 in patients, difference = 3.7, 95% CI = 1.7 to 5.7, P =.001; mean Fsp(PBS) in T cells: 6.8 in healthy donors versus 0.9 in patients, difference = 5.9, 95% CI = 2.5 to 9.3, P =.002). P-STAT1 was detected in the NK and T cells of two patients who received IFN alpha-2b immunotherapy (20 MU/m2 [MU = million units], administered by intravenous injection). P-STAT1 levels in the PBMCs of a patient treated sequentially with 5 MU/m2 and 10 MU/m2 IFN alpha-2b (administered by subcutaneous injection) also increased in response to treatments with IFN alpha-2b but did not increase further with the increased dosage of IFN alpha-2b. CONCLUSION: This flow cytometry method can be used to monitor STAT1 activation within subsets of immune cells from patients undergoing IFN alpha immunotherapy.

IL-12 pretreatments enhance IFN-alpha-induced Janus kinase-STAT signaling and potentiate the antitumor effects of IFN-alpha in a murine model of malignant melanoma.

IFN-alpha 2b (IFN-alpha) has been used to treat patients with metastatic malignant melanoma and patients rendered disease-free via surgery but at high risk for recurrence. We hypothesized that IL-12 pretreatments would result in endogenous IFN-gamma production, and that this, in turn, would up-regulate levels of Janus kinase-STAT signaling intermediates and lead to increased expression of genes regulated by IFN-alpha. Treatment of PBMCs with IL-12 stimulated a significant and dose-dependent production of IFN-gamma. Pretreatment of PBMCs and tumor cells with IFN-gamma-containing supernatants from IL-12-stimulated PBMCs led to up-regulation of STAT1, STAT2, and IFN regulatory factor 9 (IRF9) and potentiated IFN-alpha-induced STAT signaling within PBMCs and tumor cells. These effects were abrogated by neutralization of IFN-gamma in the PBMC supernatants with an anti-IFN-gamma Ab. Pretreatment of HT144 melanoma cells and PBMCs with IFN-gamma or IFN-gamma-containing supernatants enhanced the actions of IFN-alpha at the transcriptional level, as measured by real-time RT PCR analysis of the IFN-stimulated gene 15. Experiments in wild-type C57BL/6 and IFN-gamma receptor knockout (B6.129S7-Ifngr(tm1Agt)) mice demonstrated that a regimen of IL-12 pretreatment, followed by IFN-alpha, could cure mice of i.p. B16F1 melanoma tumors (p < 0.007), whereas mice treated with either agent alone or PBS succumbed to fatal tumor burden. However, this treatment regimen did not significantly prolong the survival of IFN-gamma-deficient (B6.129S7-Ifng(tm1Ts)) mice compared with mice treated with IFN-alpha alone. These results suggest that the response to IFN-alpha immunotherapy can be significantly enhanced by IL-12 pretreatment, and this effect is dependent upon endogenous IFN-gamma production and its actions on melanoma cells.