Terminal deoxynucleotidyl transferase in human lymphomas: possible existence of forms with high and low molecular weights

Abstract

Optimized methods for extraction and enzyme assay in crude tissue preparations were used to determine the amounts of terminal deoxnucleotidyl transferase (TdT) in malignant lymphomas. The TdT concentration was increased only in lymphoblastic lymphomas (LL) and was as high in these tumours as in the white blood cells from untreated patients with acute lymphoblastic leukaemia (ALL). The enzymes extracted from such lymphomas and from the leukaemic lymphoblasts had the same properties. Moreover, forms of TdT with low and high mol. wt were found in the LL tumours, similar to other reports of TdT-positive leukaemias. The overall study points at some basic biochemical identity of certain lymphoblastic malignancies, irrespective of whether the transformed cells are in solid tumours or are disseminated in the blood.

Adenosine deaminase and terminal deoxynucleotidyl transferase in human lymphomas: An aid to the diagnosis and subclassification of lymphoblastic lymphomas

“…The histological diagnoses are listed in Table I, where it can be seen that all the main histological groups of NHL are represented. Under our experimental conditions [7], cases were defined as negative if they had a TdT content below 0.1 U/mg of protein, while the positive ones were all above 2.5 U/mg of protein. Terminal deoxynucleotidyl transferase was not detected in lymphomas other than lymphoblastic, including ten cases of the immunoblastic type.…”

“…Unlabeled nucleotides and nucleosides were from PL Biochemicals, Milwaukee, Wisconsin. Poly (dA)55 was prepared enzymatically in our laboratory as previously described [7]. All the other chemicals and biochemicals were of the purest grade from commercial sources.…”

“…In all the cases, immediately after excision of a portion for enzymatic analysis, the samples were cut, frozen, and stored at -70°C until use. At the time of the enzymatic studies, tissues were thawed and processed as previously described [7]. Enzymatic activities were tested on the supernatant fraction obtained after centrifugation at 100,OOOg for 60 min.…”

“…TdT was tested with poly(dA)55 as primer and [3H]-dGTP as substrates, as previously described [7]. The ADA was assayed by measuring spectrophotometrically at 265 nm the conversion of adenosine in inosine [13].…”

Multienzymatic analyses of human malignant lymphomas. Correlation of enzymatic data with pathologic and ultrastructural findings in Burkitt's and lymphoblastic lymphomas

“…At the moment of the enzymatic studies, tissues were thawed and processed as described in a previous report. 18 Enzymatic activities were tested on the supernatant fraction obtained after centrifugation at 100,000 X g for 60 minutes. l 8 Proteins were measured according to Bradford24 using gamma globulin as a standard; the protein content ranged between 3 and 10 mg/ml.…”