Naveed Yousuf

Simultaneous immunohistochemical detection of IUdR and BrdU infused intravenously to cancer patients

Cell cycle kinetics of solid tumors in the past have been restricted to an in vitro labeling index (LI) measurement. Two thymidine analogues, bromodeoxyuridine (BrdU) and iododeoxyuridine (IUdR), can be used to label S-phase cells in vivo because they can be detected in situ by use of monoclonal antibodies (MAb) against BrdU (Br-3) or IUdR (3D9). Patients with a variety of solid tumors (lymphoma, brain, colon cancers) received sequential intravenous IUdR and BrdU. Tumor tissue removed at the end of infusion was embedded in plastic and treated with MAb Br-3 and 3D9 sequentially, using a modification of a previously described method. Clearly single and double labeled cells were visible, which enabled us to determine the duration of S-phase (Ts) and the total cell cycle time (Tc), in addition to the LI in these tumors. Detailed control experiments using tissue culture cell lines as well as bone marrow cells from leukemic patients are described, including the comparison of this double label technique with our previously described BrdU-tritiated thymidine technique. We conclude that the two methods are comparable and that the IUdR/BrdU method permits rapid and reliable cell cycle measurements in solid tumors.

In situ cell cycle kinetics in bone marrow biopsies following sequential infusions of IUdR/BrdU in patients with hematopoietic malignancies

Examination of the proliferative characteristics of myeloblasts was undertaken in situ in bone marrow (BM) biopsies of patients with acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) following sequential infusions of iodo- (IUdR) and bromodeoxyuridine (BrdU). The ability to identify S-phase cells which have incorporated both or either one of the labels in vivo by using two monoclonal antibodies in vitro permitted the measurement of labeling index (LI) and durations of S-phase (Ts) and the total cell cycle (Tc) both from the BM aspirates and biopsies. While the LI is 2-3 times higher in biopsies, Ts and Tc are fairly comparable in the two samples in 8/10 cases (p = 0.02 and 0.003 respectively). Advantages associated with the determination of cell cycle parameters in BM biopsies have been discussed at length.

Biological significance of cell cycle kinetics in 128 standard risk newly diagnosed patients with acute myelocytic leukaemia

Bromodeoxyuridine (BrdU) was administered to 128 newly diagnosed patients with standard risk acute myelocytic leukaemia (AML) for cell cycle measurements. Labelling indices (LI) were obtained from both the bone marrow aspirate (BMasp) and biopsies (bx) and durations of S‐phase (Ts) and total cell cycle time (Tc) were measured by double‐labelling the S‐phase cells in vitro with tritiated thymidine. Median LI BMasp was 8% and from BMbx was 25%. The median Ts was 12 h (range 3·1–35 h) and Tc was 48 h (range 11·5–211 h). All patients received induction therapy with a combination of cytosine arabinoside and an anthracycline. Outcome of therapy or FAB type were not related to cell cycle characteristics. Patients with above median LI BMasp, however, had longer remission durations (P= 0·03) as did patients with above median Ts (P= 0·03) and Tc (P= 0·03). Upon longer follow‐ups, even some of the patients with slowly cycling myeloblasts have relapsed (log rank P= 0·453 and 0·203 for Ts and Tc respectively). We conclude that patients with rapidly cycling cells tend to relapse faster; however, slowly cycling nature of myeloblasts is not associated with curability.

In vivo determination of cell cycle kinetics of non-Hodgkin's lymphomas using iododeoxyuridine and bromodeoxyuridine.:

Using sequential infusions of two S-phase-specific drugs, iododeoxyuridine and bromodeoxyuridine, we have developed an in vivo method for determining the labeling index (LI), the S-phase duration (Ts), and total cell cycle times (Tc) of non-Hodgkins lymphomas. In nine non-Hodgkins lymphomas studied, the LI ranged from 1.5% in a follicular small cleaved-cell lymphoma to 29.6% in a diffuse large-cell lymphoma. The Ts ranged from 16 hr in a large-cell lymphoma (immunoblastic type) to 117 hr in a follicular small cleaved-cell lymphoma. The Tc varied from 69 hr in a large-cell lymphoma (immunoblastic type) to over 1000 hr in all low-grade lymphomas studied. Immunohistochemical methods using anti-BrdU antibodies were used to detect cell incorporation of the two S-phase-specific drugs. In this manner, cell cycle times could be calculated while the architecture of the tumor specimen was preserved. Difficulties in using this methodology, specifically in the calculation of the growth fraction and total cell cycle times, are pointed out. This in vivo method does, however, allow for Ts calculations independent of growth fraction considerations. Correlations of cell cycle data with various biological and clinical factors await further patient follow-up.

Contribution of in vivo proliferation/differentiation studies toward the development of a combined functional and morphologic system of classification of neoplastic diseases.

Proliferation kinetics of both leukemia and a variety of solid tumors have been assessed after in vivo infusions of the thymidine analogues, iododeoxyuridine (IUdR) and bromodeoxyuridine (BrdU). In acute myeloid leukemia (AML), these data indicate that the pretherapy cell cycle time (Tc) of myeloblasts is a prognostic indicator for remission duration since patients with slowly cycling myeloblasts had more durable remissions. The presence of in vivo differentiation detected from the day 7 biopsy after chemotherapy was also of favorable prognosis as these individuals had statistically significant improvement in their remission duration. The data in solid tumors are not mature enough for determining their clinical significance. Since cell kinetic information is readily available in a prompt fashion using these novel techniques, data can be used to plan therapeutic strategies for patients. This review discusses the state‐of‐the‐art techniques available for cell cycle kinetic studies and the clinical and prognostic utility of data that have been generated thus far. Cancer 1992; 69:1557‐1566.

Cell Cycle Parameters as Biological Predictors of Prognosis in AML: A Review and Update of Cell Cycle Kinetics and Remission Induction/Duration in Acute Leukemia

Although the prognostic and clinical significance of cell cycle kinetic studies in neoplastic diseases has been inconclusive at worst and controversial at best, new advances in techniques to study cell cycle characteristics have dramatically improved our ability to more accurately measure the parameters of labeling index (LI), S-phase time (Ts) and total cell cycle time (Tc), and subsequently to find any correlations which would enable us to use these as prognostic indicators. Data from 285 patients with acute myeloid leukemia (AML) who were given in-vivo infusion of the thymidine analogue bromodeoxyuridine (BrdU) prior to chemotherapy show differences in mean labeling indices derived from bone marrow aspirates versus biopsies-being 9.2% and 22.2% respectively. The Tc and Ts were obtained by double labeling the aspirates with tritiated thymidine in-vitro. In 102 uniformly treated patients with standard risk de novo AML, correlations between cell cycle parameters thus measured and clinical data were sought...

Cell cycle and clinical characteristics of patients with acute myeloid leukemia and myelodysplasia whose biopsies are reactive with anti-factor VIII antibody

Abstract Presence of megakaryocytic cells in patients with myeloid disorders were investigated by staining plastic embedded biopsy sections with an anti-Factor VIII antibody (AFA). Two hundred and fifty cases were studied, 207 of whom had acute myeloid leukemia (AML) while 43 had myelodysplastic syndromes (MDS). Abnormal clusters of AFA positive cells indicating multilineage disease were identified in 17% with primary AML ( 30 175 ), 38% with secondary AML ( 12 32 ) and 42% cases of MDS ( 18 43 ). Biological characteristics of these 60 AFA positive cases were investigated. No unique differences in cell cycle characteristics following bromodeoxyuridine (BrdU) were identified. We confirm several recent reports that the incidence of multilineage involvement in AML is substantial.

Cell cycle parameters and DNA ploidy in colorectal carcinomas

Seven patients with colorectal adenocarcinoma and one with squamous cell carcinoma of anorectal region were infused preoperatively with iododeoxyuridine (IUdR) and bromodeoxyuridine (BrdU) in sequence (100 mg/m2 x 1 hr each with 1-hr interval in between) to label S-phase cells. The tumor biopsy specimens were embedded in glycol-methacrylate and 2-microns thick sections were treated with two monoclonal antibodies which permitted the identification of cells which incorporated IUdR only, BrdU only, both IUdR and BrdU, or neither IUdR or BrdU. The labeling index of tumors varied from 17.3 to 35.6% (mean = 25.78 +/- 6.162), duration of S-phase ranged from 14.0 to 23.9 hr (mean = 18.73 +/- 3.712), and total cell cycle time ranged from 39.4 to 123.4 hr (mean = 76.78 +/- 24.165). The architecture of the tumor was well preserved and a variable number of DNA synthesizing mononuclear cells were identified within and around the tumor. Image analysis of Feulgen-stained smears of the tumors was done to measure the DNA content of seven tumor samples. Each tumor was found to be hyperdiploid with multiple modal values. The studies described here demonstrate the feasibility of performing cell cycle kinetic measurements on gastrointestinal tumors which have been labeled in vivo. The ability to perform these measurements on tumor biopsies allows the avoidance of artifacts introduced when solid tumors are disaggregated in vitro for study.

Detection of single-stranded DNA damage using monoclonal anti-thymidine antibody

A method to detect single-stranded DNA damage from individual cells has been developed using a monoclonal anti-thymidine antibody (MoAb20B7). Initially, HL-60 cells were incubated with daunomycin at different concentrations, and processed by MoAb20B7. While 73.5% of the cells incubated with 5 micrograms/ml of daunomycin for 24 h reacted positively with MoAb20B7, 83.5% cells at 10 micrograms/ml daunomycin dose were positive. Next, this method was combined with unscheduled DNA synthesis to simultaneously measure repair and damage from individual cells. Finally, patients with acute myeloid leukemias were studied before and 24 h after therapy with a daunomycin containing regimen. In vivo damage could be determined in a prompt fashion.