Medical treatment of metastatic adrenal cancer is largely unsuccessful and has considerable toxicity. We previously demonstrated the activity of the plant toxin gossypol against human adrenal cancers in nude mice. We therefore examined the efficacy and toxicity of oral gossypol as a treatment for adrenal cancer in humans. Twenty-one patients with metastatic adrenal cancer received oral gossypol at doses of 30-70 mg/day. Patients were monitored for side effects of gossypol, changes in hormone secretion, and tumor response. Eighteen patients completed at least 6 weeks of gossypol treatment. Three of these patients, whose tumors were refractory to other chemotherapeutic agents, had partial tumor responses (> or = 50% decrease in tumor volume) that lasted from several months to over 1 yr. One patient had a minor response followed by resection of her remaining disease, 1 patient had stable disease, and 13 patients had disease progression. Three patients died of their disease without receiving sufficient gossypol to achieve detectable drug levels, and were eliminated from the final analysis. The side effects of gossypol were generally well tolerated; the only serious side effect was abdominal ileus that resolved when the drug was temporarily withheld and restarted at a lower dose. We conclude that oral gossypol can be used relatively safely on an outpatient basis for the treatment of metastatic adrenal cancer. The response rate is similar to the other agents currently available for adrenal cancer, and responses were seen in patients who had failed other chemotherapeutic regimens. This study provides the first indication that gossypol may have activity against cancer in humans, suggesting the need for further investigation of gossypol as an antitumor agent.

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Some children with juvenile hypothyroidism exhibit unexplained precocious puberty. Interaction of TSH with the human FSH receptor (hFSH-R) is a possible pathophysiological mechanism for this syndrome that has not been explored due to the lack of hFSH-free TSH preparations and the scarcity of a suitable hFSH-R-based assay system. To devise an in vitro FSH bioassay suitable for exploring this mechanism, we expressed hFSH-R complementary DNA in COS-7 cells and stimulated them with recombinant hTSH (rec-hTSH). Rec-hTSH elicited a dose-dependent cAMP response in the in vitro hFSH-R bioassay; however, the concentration of rec-hTSH required for half-maximal stimulation was several logs greater than that of hFSH. Rec-hTSH acted as a competitive inhibitor of hFSH at the hFSH-R, indicating that hTSH and hFSH are acting through the same receptor, namely the hFSH-R. This provides a potential novel mechanism for the precocious puberty of juvenile hypothyroidism.

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Separate sites for glycoprotein hormone receptor binding and signal transduction have yet to be elucidated. In general, certain peptide regions are thought to be critical for receptor binding, whereas the oligosacharides are thought to be important for signal transduction. Using site-directed mutagenesis of FSH, we made selective amino acid substitutions and oligosaccharide alterations to try and identify specific sites mediating receptor binding distinct from signal transduction and vice versa. We substituted Lys or Asp for beta Arg35 in the purported receptor binding loop between cysteine-32 and -51, and we substituted Gln for alpha Asn52, alpha Asn78, beta Asn7, or beta Asn24, the attachment sites for each of the oligosaccharide side-chains. We determined the binding and signal-transducing activity of wild-type and mutant human FSH at the human FSH receptor, as recent data suggest that glycoprotein hormone-receptor interactions are species specific. The binding activities of FSH with Lys or Asp substituted for beta Arg35 were reduced 71% and 98%, respectively, but their signal transduction, at equivalent levels of binding activity, was unaffected. The binding activity of FSH lacking the oligosaccharide at alpha Asn52 was enhanced 2- to 3-fold, but its signal-transducing activity, at equivalent levels of receptor binding, was decreased 72%. In contrast, the binding and signal-transducing activities of FSH lacking the alpha Asn78, or alpha Asn7, or beta Asn24 oligosaccharide were unaffected. Thus, a specific amino acid (beta Arg35) is important for high affinity binding, but is not involved in signal transduction, whereas a specific oligosaccharide (alpha Asn52) is important for signal transduction, but is not required for high affinity binding. Therefore, receptor binding and signal transduction are dissociable functions involving different sites on the FSH glycoprotein.

IN our last paper in this Journal (xxxvii. 1908, p. 77) we brought forward evidence which showed that the duration of the period in which the breath can be held depends on the relative partial pressures in the alveolar air of 02 and CO2.Under ordinary conditions the 'breaking point' is reached when the CO tension has risen to 6-7 o/o of an atmosphere and the 02 tension fallen to 9-10 0/0 of an atmosphere. On breathing the expired air in and out of a small bag, we found that the C02 tension rose to about 8 0/0, and the 02 fell to about 85-45 0/0 before the breaking point occurred.We concluded from this that "holding the breath produices some mechanical obstruction to the circulation by the cessation of the respiratory pump."I The fact that the tension of C02 can be raised by breathing 02, from 6-7 0/0 to 8-10 0/0 before the breaking point occurs, led us to try the effect of inhalations of oxygen both on the power to carry on muscular exercise on trained athletes and on untrained persons.An account of results obtained has been published in several short papers. Experiments on short distance runners are described in the Brit. Med. Journ. Aug. 28, 1908. In the same Journal, Oct. 3, 1908, is an account of the effect of oxygen on Wolffe, a cross channel swimmer. We have described a number of experiments on the effect of inhalation of oxygen while running, boxing and stair-climbing (Proc. Physiol. Soc. Jan. 23. This Journal, xxxviii. 1909). The experiments showed that oxygen inhaled before muscular exertion enables it to be carried out more easily, and inhaled after exercise diminishes the distress and the fatigue. Our conclusions were however contested by Douglas and PH. XL 23

Anti-FSH receptor antibodies, detected using animal systems, have been reported in a few patients with premature ovarian failure (POF). However, assays based on animal receptors may be inappropriate for detecting inhibiting antibodies in humans. Accordingly, we tested for interfering antibodies in patients with POF using a recombinant system expressing human (h) FSH and LH receptors. A mouse adrenal cell line transfected with the hFSH receptor (Y1-hFSHR) exhibits a dose-dependent increase in progesterone when exposed to hFSH. An embryonal kidney cell line transfected with the hLH receptor gene (hLHR-293) exhibits a dose-dependent increase in cAMP when exposed to hLH. We isolated immunoglobulins G (IgG) from 38 patients with POF and 14 normal women. We stimulated Y1-hFSHR and hLHR-293 cells with hFSH or hLH in the presence of these IgG and determined the resulting progesterone or cAMP response. The progesterone and cAMP responses obtained in the presence of IgG from patients with POF did not differ significantly from the responses in the presence of IgG from normal women. In contrast, antigonadotropin polyclonal antibodies isolated in the same manner as the above IgGs caused a greater than 90% reduction in the response of the Y1-hFSHR and hLHR-293 cells. We did not detect inhibitory antibodies in any of our 38 patients with POF. Therefore, if blocking antibodies interfering with gonadotropin-receptor interaction are a mechanism for POF, they account for a small minority of cases (< 8%).

FSH has four asparagine-linked oligosaccharides with variable sialic acid contents, so that FSH is not a single molecule, but a heterogeneous group of isoforms. These isoforms differ in their biological properties and their distribution changes in various physiological states, allowing the modulation of FSH activity. Recombinant human (h) FSH has been produced in Chinese hamster ovary cells and has an isoform profile similar to those of both pituitary FSH standard and purified urinary FSH. These FSH preparations, however, do not contain the full spectrum of FSH isoforms found in the circulation. Production of recombinant hFSH in a cell line with a different pattern of glycosylation could broaden its isoform profile and potentially alter its biological activity. Thus, we transfected human embryonal kidney cells (293) with the human alpha and FSH beta genes to produce recombinant hFSH (hFSH-293) and determined its biological activity in a rat granulosa cell bioassay. Although hFSH-293 was immunologically indistinguishable from pituitary FSH standard, its biological potency was 3- to 6-fold higher than those of two different pituitary FSH standards. To investigate this increased potency, we separated the isoforms of hFSH-293 by chromatofocusing and determined their biological potencies in the rat granulosa cell bioassay. The isoform profile of hFSH-293 demonstrated a greater number of basic isoforms than that of pituitary FSH standard. Several of these basic isoforms exhibited enhanced in vitro biological potency, accounting for the increased biological potency of hFSH-293. This pattern of high in vitro biological activity and more basic isoforms is analogous to the FSH circulating during GnRH stimulation, pubertal induction, and ovulation.