doi:10.1369/jhc.7A7213.2007
Volume 55 (8): 867-875, 2007 Copyright ©The Histochemical Society, Inc. Combined Staining of TAG-72, MUC1, and CA125 Improves Labeling Sensitivity in Ovarian Cancer: Antigens for Multi-targeted Antibody-guided Therapy
Cancer Biology Research Institute, Sanford Research/USD (SCC,NV,DMM,KAD,MJ), Department of Obstetrics and Gynecology (SCC,MCB,MJ), Department of Laboratory Medicine (MDK), Sanford School of Medicine, The University of South Dakota, Sioux Falls, South Dakota, and Department of Mathematics, The University of South Dakota, Vermillion, South Dakota (YL) Correspondence to: Subhash C. Chauhan, PhD, Cancer Biology Research Institute, Sanford Research/USD, Department of Obstetrics and Gynecology and Basic Biomedical Science Division, Sanford School of Medicine, The University of South Dakota, 1400 W. 22nd St., Sioux Falls, SD 57105. E-mail: subhash.chauhan{at}usd.edu
Single antigen-targeted intraperitoneal radioimmunotherapy for ovarian cancer has shown limited success. Due to the heterogeneous expression of tumor antigens on cancer cells, a multi-antigen targeting approach appears logical to augment the therapeutic efficacy of antibody-guided therapy. In the interest of developing this novel approach, ovarian cancer tissue microarray slides containing cancer and benign/non-neoplastic tissue samples (n=92) were processed for single-, double-, and triple-antigen labeling using antibodies for the tumor-associated antigens TAG-72, MUC1, and CA125. Among all ovarian cancer types, 72%, 61%, and 50% of the samples showed immunolabeling for TAG-72, MUC1, and CA125, respectively. Expression level of these antigens was significantly (p<0.005) higher in advanced stage carcinomas compared with early stage. Of the 48 epithelial ovarian cancer samples, individual anti-TAG-72, MUC1, and CA125 antibody probing showed labeling in 89.5%, 87.5%, and 73.0% of the cases, respectively. In the majority of the cancer samples (>70%), a heterogeneous labeling pattern was observed (only 3040% of the cancer cells within the sample were labeled). However, upon combining the three antigens (triple-antigen labeling), 98% of the epithelial ovarian cancer samples were labeled and >95% of the cancer cells within each sample were labeled. Our data indicate that the heterogeneous expression of cancer antigens appears to be a major obstacle in antibody-guided therapy, and this can be overcome by multiple antigen targeting. Therapeutic efficacy of antibody-guided therapy for ovarian cancer treatment will be enhanced by the combined targeting of TAG-72, MUC1, and CA125. (J Histochem Cytochem 55:867875, 2007)
Key Words: ovarian cancer ovarian cancer therapy TAG-72 MUC1 CA125
OVARIAN CANCER is the fifth most common cause of cancer-related deaths among women in the U.S., accounting for 16,000 deaths per year (Jemal et al. 2006
Radioimmunotherapy (RIT), the use of radioisotopes combined with monoclonal antibodies (MAbs), has shown promising results in the effective treatment of hematological malignancies, especially non-Hodgkin's lymphomas (NHL) (DeNardo et al. 1999
CA125, which is in clinical use as an ovarian cancer marker, lacks sensitivity in 20% of ovarian cancers, and Rosen et al. (2005)
Clinical Samples Tissue microarray slides (AccuMax Array, ISU ABXIS Co.; Seoul, Korea) contained 72 malignant (48 epithelial ovarian cancer and 24 non-epithelial ovarian cancer) and 20 non-neoplastic (5 normal and 15 benign) ovarian tissue samples. Histological diagnoses of the ovarian cancer samples were provided along with the tissue microarray slides.
Immunohistochemistry (IHC)
Double- and Triple-antigen Labeling of Tissue Microarray Slides
Scoring Criteria
Statistical Analysis
Higher Immunolabeling of TAG-72, MUC1, and CA125 in Ovarian Cancer as Compared With Benign/Normal Ovary Labeling sensitivity of TAG-72, MUC1, and CA125 was analyzed on tissue microarray slides using IHC. Of 92 ovarian tissue samples, 72 spots were malignant tissues, 15 spots were benign, and 5 spots were normal tissue samples. TAG-72, MUC1, and CA125 labeling were observed in 72% (n=52), 61% (n=44), and 50% (n=36) of the malignant samples, respectively, whereas none of the normal samples was labeled by TAG-72, MUC1, or CA125 (n=5). Intensity and percentage of stained cancer cells was scored by an experienced pathologist (MDK) to generate mean composite staining scores. As expected, the mean composite staining scores for all targets were much higher in malignant samples than scores for normal or benign samples. TAG-72 was not detected in any of the benign ovarian tissue samples (n=15). However, MUC1 and CA125 expression was observed at low levels in benign ovarian tissue samples (Table 1 ). In comparing extent and intensity of labeling between targets, mean composite staining scores of TAG-72 (4.51 ± 0.53) and MUC1 (4.47 ± 0.48) were significantly higher compared with CA125 (3.28 ± 0.48, p<0.05; Table 1).
Tissue microarray slides contained 48 epithelial (mucinous, clear cell, transitional cell, and endometroid) and 24 non-epithelial types of carcinomas. Among the 48 epithelial ovarian cancer samples, TAG-72, MUC1, and CA125 labeled 89.5%, 87.5%, and 73.0% of the cases, respectively. Additionally, mean composite staining scores of the epithelial cancer samples were higher than the scores attained for all types of ovarian cancer. For the ovarian epithelial cancers, mean composite staining score of MUC1 (6.42 ± 0.80) was significantly higher than CA125 (4.15 ± 0.71, p<0.05; Table 1). Of the 24 non-epithelial cancers (Brenner, yolk sac, granulosa, and dysgerminoma, n=6 of each type), TAG-72 showed a positive reactivity in 100% of the dysgerminoma (n=6) and 16.6% of the Brenner samples (n=1), whereas MUC1 showed a detectable labeling in only 66.6% of the Brenner samples (n=4). CA125 labeling was detectable in only 16.6% of each Brenner (n=1) and granulosa (n=1) tumor samples.
Prominent Immunolabeling of TAG-72, MUC1, and CA125 in Advanced Cancer Stage
Immunolabeling of TAG-72, MUC1, and CA125 in Epithelial Ovarian Cancer Samples In 90% of cases, ovarian cancer originates from the ovarian surface epithelium; therefore, epithelial types of ovarian carcinoma (EOC) are most common. Based on the cellular morphology, epithelial cancer samples were grouped into five major histological types: serous, mucinous, clear cell, transitional cell, and endometroid. To be an effective target antigen for radioimmunotherapy, protein expression level should be high enough to result in +2 or +3 labeling intensity. Among EOCs, TAG-72, MUC1, and CA125 showed +2 and +3 labeling intensity in 89.5%, 87.5%, and 73% of the samples, respectively (Table 3 ). Among different histological types of EOCs, TAG-72 showed immunolabeling in 100% of serous and transitional types of samples. MUC1 was detected in 100% of transitional and endometroid types of samples. CA125 showed maximum (90%) labeling in clear cell samples and labeled only 40% of the mucinous samples (Table 3).
Heterogeneous Labeling of TAG-72, MUC1, and CA125 in Ovarian Cancer We have observed labeling of TAG-72, MUC1, and CA125 in 7589% of the EOC samples (Table 3). Additionally, only 3040% of the cancer cells were immunolabeled within the majority of the cancer samples (>70%). Figure 1 shows representative examples of the heterogeneous immunolabeling pattern of TAG-72, MUC1, and CA125 in different epithelial ovarian cancer types. None of the cancer antigens showed a homogeneous expression pattern in >20% of the cancer samples. These data clearly suggest that an antibody-guided therapy using only a single target antigen will have limited therapeutic efficacy because only a fraction of cancer cells in the tumor are targeted.
Multi-antigen Staining Procedure Labeled a Markedly Higher Percentage of Cancer Cells in Tumors IRIT studies for ovarian cancer treatment have shown limited therapeutic benefit, possibly due to heterogeneous expression of the single target antigen by ovarian cancer cells. Therefore, single antigen-targeted IRIT fails to target a significant number of ovarian cancer cells. A multi-antigen targeting approach for IRIT procedures appears to be logical to overcome the heterogeneous expression of the targeting antigen. Accordingly, we sought to determine the combined immunolabeling of TAG-72, MUC1, and CA125 in ovarian cancer tissues. An irregular and heterogeneous labeling of CA125, MUC1, and TAG-72 is clearly evident in double and triple immunolabeling (Figure 2 ). In double-staining procedures, a combination of MUC1 + TAG-72 and MUC1 + CA125 labeled a markedly higher percentage of cells than the single antigen-staining procedure (Figures 2A and 2B and Figure 3 ). Moreover, triple staining (labeling three antigens on the same sample) achieved >95% labeling of ovarian cancer cells in 98% of epithelial ovarian cancer samples (Figures 2C2E and Figure 3; Table 3). Multi-antigen labeling certainly stained a higher percentage of ovarian cancer cells, and these data clearly suggest the requirement of multi-antigen targeting approaches to effectively target and obliterate the majority of cells within a cancerous tumor.
Significant advancements have been achieved in the field of cancer therapeutics in recent years; however, the survival of ovarian cancer patients has increased only moderately during the past several decades (Jemal et al. 2006 Labeling sensitivity of three most commonly used targeting antigens for ovarian cancer treatment, TAG-72, MUC1, and CA125, was analyzed in situ by IHC as a direct measure of antigen labeling. Ovarian tissue microarray slides were used to avoid discrepancies while performing IHC procedures with a large number of samples. TAG-72, MUC1, and CA125 were overexpressed in ovarian cancer samples as compared with benign/normal ovarian samples (Table 1). Additionally, expression of these antigens was significantly higher in advanced stage cancer samples compared with early stage cancer samples (Table 2). However, none of the single cancer antigens showed expression in 100% of the epithelial ovarian cancer samples (Table 3). Nonetheless, in combination TAG-72, MUC1, and CA125 labeled a considerably higher number (98%) of ovarian tissue samples in each of the categories compared with any of the single antigen-labeling procedures (Table 3). Our results show that the cells within a cancerous tumor heterogeneously express TAG-72, MUC1, and CA125 in the majority (>70%) of ovarian cancer samples (Figure 1). Heterogeneous expression of a tumor-targeting antigen may limit the therapeutic efficacy of a single antigen-targeted antibody therapy because a significant number of cells will not be targeted. The most promising way to improve the therapeutic efficacy of antibody-guided therapy will be the utilization of an antibody cocktail that can target multiple cancer antigens and thereby can label a higher number of cancer cells in a tumor. To determine the efficacy of this approach, double- and triple-antigen labeling were performed on ovarian cancer tissue microarray slides. In these experiments, the same ovarian cancer tissue arrays were probed with a cocktail of antibodies, i.e., anti-MUC1 + anti-CA125 and anti-MUC1 + anti-TAG-72 for double-antigen staining and a cocktail of anti-MUC1 + anti-TAG-72 + anti-CA125 for triple-antigen staining. Results of these experiments clearly demonstrate that in double- and triple-staining procedures the cocktail of antibodies labeled a markedly higher percentage of cancer cells within a tumor as compared with any of the single antigen-labeling procedures (Figure 2 and Figure 3).
Ovarian cancer is a highly metastatic disease. The poor outcome of this disease is associated with the high frequency of peritoneal metastatic seeding of the EOCs and their growth as ascites in the abdominal cavity (Auersperg et al. 1998
The aforementioned studies clearly demonstrate that antibody-guided RIT may be an effective alternative therapeutic modality for ovarian cancer treatment if properly modified and optimized. To prevail over the heterogeneic expression of TAAs by ovarian cancer cells and to target different sizes of tumor nodules, a multi-antigen targeting approach using therapeutic radionuclides of different LET properties will be an enviable alternative. However, a potential problem of IRIT using MUC1 is normal organ toxicity because it is expressed in some normal organs. Therefore, MUC1 targeting antibodies against the tandem repeat region will be ideal because this region is differentially glycosylated in normal (hyperglycosylated) vs cancer cells (hypoglycosylated) (Hollingsworth and Swanson 2004
In the future, nanoparticle therapeutics will also be based on molecular targeting, which can be achieved by using nanoparticles linked to ligands such as MAbs/antibody fragments that are directed against cancer-associated antigens. Immunonanoparticles will combine antibody-mediated tumor recognition with nanoparticle-mediated anti-cancer drug delivery. An immunoliposome consisting of novel anti-HER2 scFv F5 conjugated to phospholipase D, currently in development, is selectively bound to and internalized by HER2-overexpressing tumor cells (Park et al. 1995 In our double- and triple-staining experiments, we show for the first time that, in combination, TAG-72, MUC1, and CA125 label a broad spectrum of ovarian cancer cells within tumor samples. This study suggests that these tumor antigens are highly expressed in advanced stage samples and may be target antigens of interest for developing multi-antigen IRIT for the effective treatment of advanced stage ovarian cancer.
This research was supported by a Sanford Research/USD grant. The authors acknowledge Kelley Vannatta for technical support. We also thank Dr. Keith Miskimins, Director, Cancer Biology Research Institute, for critical review and suggestions.
Received for publication February 19, 2007; accepted April 5, 2007
Alexander-Sefre F, Menon U, Jacobs IJ (2002) Ovarian cancer screening. Hosp Med 63:210213[Medline] Alvarez RD, Huh WK, Khazaeli MB, Meredith RF, Partridge EE, Kilgore LC, Grizzle WE, et al. (2002) A phase I study of combined modality 90Yttrium-CC49 intraperitoneal radioimmunotherapy for ovarian cancer. Clin Cancer Res 8:28062811 Alvarez RD, Partridge EE, Khazaeli MB, Plott G, Austin M, Kilgore L, Russell CD, et al. (1997) Intraperitoneal radioimmunotherapy of ovarian cancer with 177Lu-CC49: a phase I/II study. Gynecol Oncol 65:94101[CrossRef][Medline] Armstrong DK (2002) Relapsed ovarian cancer: challenges and management strategies for a chronic disease. Oncologist 7(suppl 5):2028 Auersperg N, Edelson MI, Mok SC, Johnson SW, Hamilton TC (1998) The biology of ovarian cancer. Semin Oncol 25:281304[Medline] Auersperg N, Wong AS, Choi KC, Kang SK, Leung PC (2001) Ovarian surface epithelium: biology, endocrinology, and pathology. Endocr Rev 22:255288 Bast RC Jr, Badgwell D, Lu Z, Marquez R, Rosen D, Liu J, Baggerly KA, et al. (2005) New tumor markers: CA125 and beyond. Int J Gynecol Cancer 15(suppl 3):274281[CrossRef][Medline] Batra SK, Jain M, Wittel UA, Chauhan SC, Colcher D (2002) Pharmacokinetics and biodistribution of genetically engineered antibodies. Curr Opin Biotechnol 13:603608[CrossRef][Medline] Behr TM, Behe M, Stabin MG, Wehrmann E, Apostolidis C, Molinet R, Strutz F, et al. (1999) High-linear energy transfer (LET) Behr TM, Sharkey RM, Juweid ME, Dunn RM, Vagg RC, Ying Z, Zhang CH, et al. (1997) Phase I/II clinical radioimmunotherapy with an iodine-131-labeled anti-carcinoembryonic antigen murine monoclonal antibody IgG. J Nucl Med 38:858870 Chauhan SC, Singh AP, Ruiz F, Johansson SL, Jain M, Smith LM, Moniaux N, et al. (2006) Aberrant expression of MUC4 in ovarian carcinoma: diagnostic significance alone and in combination with MUC1 and MUC16 (CA125). Mod Pathol 19:13861394[CrossRef][Medline] Crippa F, Bolis G, Seregni E, Gavoni N, Scarfone G, Ferraris C, Buraggi GL, et al. (1995) Single-dose intraperitoneal radioimmunotherapy with the murine monoclonal antibody I-131 MOv18: clinical results in patients with minimal residual disease of ovarian cancer. Eur J Cancer 31A:686690[CrossRef] DeNardo GL, O'Donnell RT, DeNardo SJ (2001) Radiolabeled anti-lymphoma antibodies. Cancer Chemother Biol Response Modif 19:297308[Medline] DeNardo SJ, Kroger LA, DeNardo GL (1999) A new era for radiolabeled antibodies in cancer? Curr Opin Immunol 11:563569[CrossRef][Medline] Epenetos AA, Munro AJ, Stewart S, Rampling R, Lambert HE, McKenzie CG, Soutter P, et al. (1987) Antibody-guided irradiation of advanced ovarian cancer with intraperitoneally administered radiolabeled monoclonal antibodies. J Clin Oncol 5:18901899 Giuntoli RL 2nd, Rodriguez GC, Whitaker RS, Dodge R, Voynow JA (1998) Mucin gene expression in ovarian cancers. Cancer Res 58:55465550 Goldenberg DM (2002) Targeted therapy of cancer with radiolabeled antibodies. J Nucl Med 43:693713 Hollingsworth MA, Swanson BJ (2004) Mucins in cancer: protection and control of the cell surface. Nat Rev Cancer 4:4560[CrossRef][Medline] Hong K, Kirpotin DB, Park JW, Shao Y, Shalaby R, Colbern G, Benz CC, et al. (1999) Anti-HER2 immunoliposomes for targeted drug delivery. Ann NY Acad Sci 886:293296[CrossRef][Medline] Janssen ML, Pels W, Massuger LF, Oyen WJ, Boonstra H, Corstens FH, Boerman OC (2003) Intraperitoneal radioimmunotherapy in an ovarian carcinoma mouse model: effect of the radionuclide. Int J Gynecol Cancer 13:607613[CrossRef][Medline] Jemal A, Siegel R, Ward E, Murray T, Xu J, Smigal C, Thun MJ (2006) Cancer statistics, 2006. CA Cancer J Clin 56:106130 Kang BK, Chon SK, Kim SH, Jeong SY, Kim MS, Cho SH, Lee HB, et al. (2004) Controlled release of paclitaxel from microemulsion containing PLGA and evaluation of anti-tumor activity in vitro and in vivo. Int J Pharm 286:147156[CrossRef][Medline] Mahe MA, Fumoleau P, Fabbro M, Guastalla JP, Faurous P, Chauvot P, Chetanoud L, et al. (1999) A phase II study of intraperitoneal radioimmunotherapy with iodine-131-labeled monoclonal antibody OC-125 in patients with residual ovarian carcinoma. Clin Cancer Res 5:32493253s Menon U, Jacobs I (2002) Screening for ovarian cancer. Best Pract Res Clin Obstet Gynaecol 16:469482[CrossRef][Medline] Meredith RF, Alvarez RD, Partridge EE, Khazaeli MB, Lin CY, Macey DJ, Austin JM Jr, et al. (2001) Intraperitoneal radioimmunochemotherapy of ovarian cancer: a phase I study. Cancer Biother Radiopharm 16:305315[CrossRef][Medline] Meredith RF, Partridge EE, Alvarez RD, Khazaeli MB, Plott G, Russell CD, Wheeler RH, et al. (1996) Intraperitoneal radioimmunotherapy of ovarian cancer with lutetium-177-CC49. J Nucl Med 37:14911496 Milenic DE, Brady ED, Brechbiel MW (2004a) Antibody-targeted radiation cancer therapy. Nat Rev Drug Discov 3:488499[CrossRef][Medline] Milenic DE, Garmestani K, Brady ED, Albert PS, Ma D, Abdulla A, Brechbiel MW (2004b) Targeting of HER2 antigen for the treatment of disseminated peritoneal disease. Clin Cancer Res 10:78347841 Milenic DE, Garmestani K, Brady ED, Albert PS, Ma D, Abdulla A, Brechbiel MW (2005) Ozols RF (2002a) Future directions in the treatment of ovarian cancer. Semin Oncol 29:3242[Medline] Ozols RF (2002b) Recurrent ovarian cancer: evidence-based treatment. J Clin Oncol 20:11611163 Ozols RF (2002c) Update on the management of ovarian cancer. Cancer J 8(suppl 1):S2230[Medline] Park JW, Hong K, Carter P, Asgari H, Guo LY, Keller GA, Wirth C, et al. (1995) Development of anti-p185HER2 immunoliposomes for cancer therapy. Proc Natl Acad Sci USA 92:13271331 Park JW, Hong K, Kirpotin DB, Meyer O, Papahadjopoulos D, Benz CC (1997a) Anti-HER2 immunoliposomes for targeted therapy of human tumors. Cancer Lett 118:153160[CrossRef][Medline] Park JW, Hong K, Kirpotin DB, Papahadjopoulos D, Benz CC (1997b) Immunoliposomes for cancer treatment. Adv Pharmacol 40:399435[Medline] Park JW, Kirpotin DB, Hong K, Shalaby R, Shao Y, Nielsen UB, Marks JD, et al. (2001) Tumor targeting using anti-her2 immunoliposomes. J Control Release 74:95113[CrossRef][Medline] Rosen DG, Wang L, Atkinson JN, Yu Y, Lu KH, Diamandis EP, Hellstrom I, et al. (2005) Potential markers that complement expression of CA125 in epithelial ovarian cancer. Gynecol Oncol 99:267277[CrossRef][Medline] Sahoo SK, Labhasetwar V (2005) Enhanced antiproliferative activity of transferrin-conjugated paclitaxel-loaded nanoparticles is mediated via sustained intracellular drug retention. Mol Pharm 2:373383[CrossRef][Medline] Sahoo SK, Ma W, Labhasetwar V (2004) Efficacy of transferrin-conjugated paclitaxel-loaded nanoparticles in a murine model of prostate cancer. Int J Cancer 112:335340[CrossRef][Medline] Schneider-Gadicke E, Humm JL, Lau CC, Macklis RM, Bastert G, Knapp RC (1992) Analysis of cytotoxicity of 131I-labelled OC125 F(ab')2 on human epithelial ovarian cancer cell lines. Radiother Oncol 23:150159[CrossRef][Medline] Sharkey RM, Goldenberg DM, Murthy S, Pinsky H, Vagg R, Pawlyk D, Siegel JA, et al. (1993) Clinical evaluation of tumor targeting with a high-affinity, anticarcinoembryonic-antigen-specific, murine monoclonal antibody, MN-14. Cancer 71:20822096[CrossRef][Medline] Thor A, Gorstein F, Ohuchi N, Szpak CA, Johnston WW, Schlom J (1986) Tumor-associated glycoprotein (TAG-72) in ovarian carcinomas defined by monoclonal antibody B72.3. J Natl Cancer Inst 76:9951006[Medline] Thor A, Muraro R, Gorstein F, Ohuchi N, Viglione M, Szpak CA, Johnston WW, et al. (1987) Adjunct to the diagnostic distinction between adenocarcinomas of the ovary and the colon utilizing a monoclonal antibody (COL-4) with restricted carcinoembryonic antigen reactivity. Cancer Res 47:505512 Vasir JK, Labhasetwar V (2005) Targeted drug delivery in cancer therapy. Technol Cancer Res Treat 4:363374[Medline]
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||