Journal of the National Cancer Institute
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J. Natl. Cancer Inst. · Oct 1980
Role of natural killer cells in the destruction of circulating tumor emboli.
A close correlation was demonstrated between levels of host natural cytotoxic (NC) and/or natural killer (NK) cell activity and capacity to eliminate blood-borne tumor cells. The outcome of experimental metastasis of several tumors with defined biologic behavior was studied in syngeneic mice exhibiting low NK cell activity [3-wk-old normal mice and cyclophosphamide (Cy)-treated adult mice] and high NK cell activity (normal adult mice). An iv injection of metastatic tumor cells into 3-week-old or Cy-treated mice markedly enhanced experimental pulmonary metastasis. ⋯ The adoptive transfer of spleen cells from syngeneic mice or allogeneic nude mice that have high NK activity shortly before (but not after) iv tumor challenge abrogated the Cy-induced enhancement of metastasis. The reactive lymphoid cells were non-T, nonadherent to nylon wool, sensitive to Cy treatment, and endowed with a natural ability to kill tumor cells during a short (12-24 hr) period. The conclusions were that NC-NK cells are important in host defense against circulating tumor cells and therefore can prevent the development of tumor cells into metastases.
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J. Natl. Cancer Inst. · Oct 1980
Preconception radiation, intrauterine diagnostic radiation, and childhood neoplasia.
Diagnostic X-ray examinations as a potential risk for neoplasia were investigated in a prospective study of 55,908 women who participated in the Collaborative Perinatal Project of the National Institute of Neurological and Communicative Disorders and Stroke. The X-ray exposure histories of 145 mothers whose children developed neoplasms and 290 matched controls were examined. ⋯ Generally, the data were consistent with increased risk of malignant neoplasms among children of women exposed to X-rays before and during pregnancy, with a somewhat higher relative risk estimate for preconception exposure. No significant association of X-ray exposure and benign neoplasms was detected.