Suppression
of N-nitroso-N-methylurea-induced second generation rat mammary
tumors with combined melatonin-tamoxifen therapy
by
Lalita Kothari, Ami Kothan , Anita Borges, Indranil Mitra, Sharayu
Kabre
Cell
Biology Division , Cancer Research Institute. Department of
Pathology , Tumor Marker Laboratory , Tata Memorial Hospital,
Tata Memorial Centre, Parel, Bombay 400012
Received: April 27, 1996
Abstract
Sprague-Dawley rats were injected with N-nitroso-N-methylurea
(NMU) (50mg/kg b.wt.) and the primary tumor which developed
within three months were excised. These tumors were found to
be ER +ve (50±4.3 fmol/mg protein). Animals were regrouped
following excision and melatonin (Mel) and/or tamoxifen (Tarn)
treatment was initiated immediately. There was uniform and significant
delay in secondary tumor appearance in all the treated groups
as compared to the untreated NMU-administered animals. The most
effective suppression was observed in animals treated with combined
therapy and histopathologically, these tumors were benign. The
combination of melatonin and tamoxifen in women having ER+ve
tumors appears to be a useful therapeutic approach.
