Cutaneous T-cell lymphomas

Interleukin-13 is overexpressed in cutaneous T-cell lymphoma cells and regulates their proliferation

Cutaneous T-cell lymphomas (CTCLs) primarily affect skin and are characterized by proliferation of mature CD4(+) T-helper cells. The pattern of cytokine production in the skin and blood is considered to be of major importance for the pathogenesis of CTCLs. Abnormal cytokine expression in CTCLs may be responsible for enhanced proliferation of the malignant cells and/or depression of the antitumor immune response. Here we show that interleukin-13 (IL-13) and its receptors IL-13Rα1 and IL-13Rα2 are highly expressed in the clinically involved skin of CTCL patients. We also show that malignant lymphoma cells, identified by the coexpression of CD4 and TOX (thymus high-mobility group box), in the skin and blood of CTCL patients produce IL-13 and express both receptors. IL-13 induces CTCL cell growth in vitro and signaling through the IL-13Rα1. Furthermore, antibody-mediated neutralization of IL-13 or soluble IL-13Rα2 molecules can lead to inhibition of tumor-cell proliferation, implicating IL-13 as an autocrine factor in CTCL. Importantly, we established that IL-13 synergizes with IL-4 in inhibiting CTCL cell growth and that blocking the IL-4/IL-13 signaling pathway completely reverses tumor-cell proliferation. We conclude that IL-13 and its signaling mediators are novel markers of CTCL malignancy and potential therapeutic targets for intervention.

An uncommon skin condition illustrates the need for caution when prescribing for friends

PURPOSE

A dual-focused case study written to discuss the legal and medical hazards of informally writing prescriptions for friends or family members and to provide knowledge of early-stage mycosis fungoides (MF), its course, and treatment.

DATA SOURCES

A review of the prescribing practices of clinicians, the cognitive processes needed in diagnosis and treatment, the current ethical guidelines, and a review of MF, its course, and treatments.

CONCLUSIONS

Treating acquaintances and family informally places clinicians at risk for liability and patients at risk for inaccurate diagnosis and treatment. This case illustrates the potential hazard of casually treating a friend for what looks like a benign condition. Resembling atopic dermatitis in its early stages, MF is the most common of a rare group of skin lymphomas. Early diagnosis and treatment are crucial for a better prognosis. Had this clinician complied with the request of her friend, his diagnosis would have been missed and timely treatment delayed.

IMPLICATIONS FOR PRACTICE

No matter what the prior relationship may have been, once a clinician treats a patient, a legally binding relationship begins, requiring the due standard of care. Nurse practitioners (NPs) need to be aware of the potential for error when treating acquaintances. Available NP standards of practice and ethical guidelines should address informal treatment situations.

Cutaneous T-cell lymphoma

OBJECTIVE

To review recent information on the epidemiology, etiology, clinical presentation, staging, treatment approaches, and nursing management of CTCL.

DATA SOURCES

Research and review articles and textbooks.

CONCLUSION

Identifying the etiology and finding a cure for cutaneous T-cell lymphoma is promising as our knowledge and understanding of the T-cell biology evolves, creating more options for innovative therapies or treatment modalities.

IMPLICATIONS FOR NURSING PRACTICE

It is essential for the oncology nurse to understand the disease process, treatment modalities, and side effect profiles to provide astute nursing assessment, establishment of treatment goals, management of cutaneous symptoms, treatment of side effects, and pain control while preventing infection and providing psychological/social support throughout the course of the disease.

In vivo activation of STAT3 in cutaneous T-cell lymphoma. Evidence for an antiapoptotic function of STAT3

A characteristic feature of neoplastic transformation is a perpetual activation of oncogenic proteins. Here, we studied signal transducers and activators of transcription (STAT) in patients with mycosis fungoides (MF)/cutaneous T-cell lymphoma (CTCL). Malignant lymphocytes in dermal infiltrates of CTCL tumors showed frequent and intense nuclear staining with anti-PY-STAT3 antibody, indicating a constitutive activation of STAT3 in vivo in tumor stages. In contrast, only sporadic and faint staining was observed in indolent lesions of patch and plaque stages of MF. Moreover, neoplastic lymphocytes in the epidermal Pautrier abscesses associated with early stages of MF did not express activated STAT3. To address the role of STAT3 in survival/apoptosis, CTCL tumor cells from an advanced skin tumor were transfected with either wild-type STAT3 (STAT3wt) or dominant-negative STAT3 (STAT3D). Forced inducible expression of STAT3D triggered a significant increase in tumor cells undergoing apoptosis, whereas forced expression of STAT3wt or empty vector had no effect. In conclusion, a profound in vivo activation of STAT3 is observed in MF tumors but not in the early stages of MF. Moreover, STAT3 protects tumor cells from apoptosis in vitro. Taken together, these findings suggest that STAT3 is a malignancy factor in CTCL.

Spontaneous interleukin-5 production in cutaneous T-cell lymphoma lines is mediated by constitutively activated Stat3

Mycosis fungoides is a low-grade cutaneous T-cell lymphoma (CTCL) of unknown etiology. In advanced stages of CTCL, a shift in cytokine profile from T(H)1 to T(H)2 is observed, which coincides with eosinophilia, high levels of immunoglobulin E, and increased susceptibility to bacterial infections. It is, however, unknown why T(H)2 cytokines predominate in advanced CTCL, and the cellular source of these cytokines also remains to be identified. In several leukemias and lymphomas, constitutively activated signal transducer and activator of transcription (Stat) signaling pathways have been detected. In a previous study, constitutive activation of Stat3 was found in tumor cells isolated from affected skin and blood from CTCL patients. Here, it is shown that CTCL tumor cell lines, but not nonmalignant cell lines, spontaneously produce interleukin-5 (IL-5), IL-6, and IL-13. Transfection of tumor cells with dominant-negative Stat3 almost completely blocks IL-5 production and strongly inhibits IL-13 production, whereas IL-6 production is unaffected. Thus, the data show that malignant CTCL cells themselves might contribute to the change in cytokine pattern accompanying progression of CTCL. In conclusion, constitutively activated Stat3 is found to mediate a spontaneous IL-5 production and regulate IL-13 production in CTCL cell lines, pointing toward a new role of Stat3 in malignant transformation.