Production of lymphokines affecting tumor cells by T-T hybridomas

Rapamycin Ameliorates Cognitive Impairments and Alzheimer's Disease-Like Pathology with Restoring Mitochondrial Abnormality in the Hippocampus of Streptozotocin-Induced Diabetic Mice

Alzheimer's disease (AD) and diabetes mellitus (DM) share common pathophysiological findings, in particular, the mammalian target of rapamycin (mTOR) has been strongly implied to link to AD, while it also plays a key role in the insulin signaling pathway. However, the mechanism of how DM and AD is coupled remains elusive. In the present study, we found that streptozotocin (STZ)-induced DM mice significantly increased the levels P-mTOR Ser2448, P-p70S6K Thr389, P-tau Ser356 and Aβ levels (Aβ oligomer/monomer), as well as the levels of Drp1 and p-Drp1 S616 (mitochondrial fission proteins) are increased, whereas no change was found in the expression of Opa1, Mfn1 and Mfn2 (mitochondrial fusion proteins) compared with control mice. Moreover, the expression of 4-HNE and 8-OHdG showed an aberrant increase in the hippocampus of STZ-induced DM mice that is associated with a decreased capacity of spatial memory and a loss of synapses. Rapamycin, an inhibitor of mTOR, rescued the STZ-induced increases in mTOR/p70S6K activities, tau phosphorylation and Aβ levels, as well as mitochondria abnormality and cognitive impairment in mice. These findings imply that rapamycin prevents cognitive impairment and protects hippocampus neurons from AD-like pathology and mitochondrial abnormality, and also that rapamycin treatment could normalize these STZ-induced alterations by decreasing hippocampus mTOR/p70S6K hyperactivity.

The role of lymphokines in neoplastic disease

In this brief review, we have focused on studies demonstrating the existence of low-molecular-weight lymphokines that modify a number of tumor cell functions. We have found that lymphokine preparations of human or murine origin contain a protein, TMIF, that can reversibly inhibit the migration of a variety of tumor cells. Both serially passaged animal tumors and spontaneous human neoplasms respond to TMIF. Determination of physicochemical characteristics, including molecular weight, enzyme inactivation, monosaccharide inhibition profile, and noncoordinate production by hybridomas, has led to the conclusion that TMIF is distinct from the lymphokines that inhibit the migration of nonneoplastic cells. TMIF can be detected in vivo and can modify the behavior of tumor cells in vivo. In addition, TMIF-containing preparations can inhibit the binding of tumor cells to endothelial monolayers. Although migration inhibition by TMIF is not associated with cytotoxicity, partially purified TMIF preparations are cytostatic for tumor cells. Cytostasis is not the cause of the observed results in the migration assay, and these properties are therefore functionally distinct. These three activities, appearing within a narrow range of molecular weights, different from those of other known lymphokines, suggest the existence of a distinct class of lymphokine mediators with the common function of influencing functional properties of tumor cells. We propose that these mediators be tentatively defined as neomodulins. Further characterization of this set of lymphocyte-derived effector macromolecules will require thorough exploration of their effects on the various functions listed as tumor cell "job descriptions," demonstration of their in vivo efficacy, and purification of the various factors to homogeneity. The neomodulins are likely to have therapeutic potential, since the tumor cell functions that they regulate are those involved in the expression of malignant potential. In addition, studies are under way to determine whether the in vitro responsiveness of tumor cells to these factors might correlate with their in vivo biologic behavior. Finally, detection of TMIF or related lymphokines in serum or urine from patients with neoplasms could be useful in the detection of cancer and/or monitoring of occult tumor metastases and tumor recurrence.