Biomedical subjects

K C Anderson

Publications and source records attributed to K C Anderson.

At least 19 recordsLinked to original sources

PubMed2001

Biologic sequelae of interleukin-6 induced PI3-K/Akt signaling in multiple myeloma.

Previous studies demonstrate that interleukin-6 (IL-6) mediates growth and survival in human multiple myeloma (MM) cells via the MEK/MAPK and JAK/STAT signaling pathways, respectively. IL-6 also confers protection against Dexamethasone (Dex)-induced apoptosis via activation of protein tyrosine phosphatase (SHP2). In the current study, we characterized IL-6 triggered phophatidylinositol-3 kinase/Akt kinase (PI3-K/Akt) signaling in MM cells. IL-6 induces Akt/PKB phosphorylation in a time and dose dependent manner in MM.1S MM cells. IL-6 also induced phosphorylation of downstream targets of Akt, including Bad, GSK-3beta, and FKHR, confirming Akt activation. Inhibition of Akt activation by the PI3-K inhibitor LY294002 partially blocked IL-6 triggered MEK/MAPK activation and proliferation in MM.1S cells, suggesting cross-talk between PI3-K and MEK signaling. We demonstrate that Dex-induced apoptosis in MM.1S cells is mediated by downstream activation of caspase-9, with resultant caspase-3 cleavage; and conversely, that IL-6 triggers activation of PI3-K and its association with SHP2, inactivates caspase-9, and protects against Dex-induced apoptosis. LY294002 completely abrogates this signaling cascade, further confirming the importance of PI3-K/Akt signaling in conferring the protective effect of IL-6 against Dex-induced apoptosis. Finally, we show that IL-6 triggered PI3-K/Akt signaling in MM.1S cells inactivates forkhead transcriptional factor (FKHR), with related G1/S phase transition, whereas LY294002 blocks this signaling, resulting in upregulation of p27(KIP1) and G1 growth arrest. Our data therefore suggest that PI3-K/Akt signaling mediates growth, survival, and cell cycle regulatory effects of IL-6 in MM.

Apoptosis↗

PubMed2001

Purging of autologous peripheral-blood stem cells using CD34 selection does not improve overall or progression-free survival after high-dose chemotherapy for multiple myeloma: results of a multicenter randomized controlled trial.

PURPOSE: Although high-dose chemotherapy supported by autologous peripheral-blood progenitor-cell (PBPC) transplantation improves response rates and survival for patients with multiple myeloma, all patients eventually develop progressive disease after transplantation. It has been hypothesized that depletion of malignant plasma cells from autografts may improve outcome by reducing infused cells contributing to relapse. PATIENTS AND METHODS: A randomized phase III study using the CEPRATE SC System (Cellpro, Bothell, WA) to enrich CD34(+) autograft cells and passively purge malignant plasma cells was completed in 190 myeloma patients randomized to receive an autograft of CD34-selected or unselected PBPCs. RESULTS: After CD34 selection, tumor burden was reduced by 1.6 to 6.0 logs (median, 3.1), with 54% of CD34-enriched products having no detectable tumor. Median time to count recovery, number of transfusions, transplantation-related mortality, and days in hospital were equivalent between the two transplantation arms. With a median follow-up of 37 months, 33 patients (36%) in the selected and 34 patients (35%) in the unselected arm had died (P =.784). Median overall survival in the selected arm was reached at 50 months and is not reached at this time in the unselected arm (P =.78). Median disease-free survival was 100 versus 104 weeks (P =.82), with 67% of patients in the selected arm and 66% of patients in the unselected arm relapsing. CONCLUSION: This phase III trial demonstrates that although CD34 selection significantly reduces myeloma cell contamination in PBPC collections, no improvement in disease-free or overall survival was achieved.

Adult↗

PubMed2001

TRAIL/Apo2L ligand selectively induces apoptosis and overcomes drug resistance in multiple myeloma: therapeutic applications.

Multiple myeloma (MM) remains incurable and novel treatments are urgently needed. Preclinical in vitro and in vivo evaluations were performed to assess the potential therapeutic applications of human recombinant tumor necrosis factor (TNF)-related apoptosis-inducing ligand/Apo2 ligand (TRAIL/Apo2L) in MM. TRAIL/Apo2L potently induced apoptosis of MM cells from patients and the majority of MM cell lines, including cells sensitive or resistant to dexamethasone (Dex), doxorubicin (Dox), melphalan, and mitoxantrone. TRAIL/Apo2L also overcame the survival effect of interleukin 6 on MM cells and did not affect the survival of peripheral blood and bone marrow mononuclear cells and purified B cells from healthy donors. The status of the TRAIL receptors (assessed by immunoblotting and flow cytometry) could not predict TRAIL sensitivity of MM cells. The anti-MM activity of TRAIL/Apo2L was confirmed in nu/xid/bg mice xenografted with human MM cells; TRAIL (500 microg intraperitoneally daily for 14 days) was well tolerated and significantly suppressed the growth of plasmacytomas. Dox up-regulated the expression of the TRAIL receptor death receptor 5 (DR5) and synergistically enhanced the effect of TRAIL not only against MM cells sensitive to, but also against those resistant to, Dex- or Dox-induced apoptosis. Nuclear factor (NF)-kappaB inhibitors, such as SN50 (a cell-permeable inhibitor of the nuclear translocation and transcriptional activity of NF-kappaB) or the proteasome inhibitor PS-341, enhanced the proapoptotic activity of TRAIL/Apo2L against TRAIL-sensitive MM cells, whereas SN50 reversed the TRAIL resistance of ARH-77 and IM-9 MM cells. Importantly, normal B lymphocytes were not sensitized to TRAIL by either Dox, SN50, or PS-341. These preclinical studies suggest that TRAIL/Apo2L can overcome conventional drug resistance and provide the basis for clinical trials of TRAIL-based treatment regimens to improve outcome in patients with MM. (Blood. 2001;98:795-804)

Animals↗

PubMed2001

The role of tumor necrosis factor alpha in the pathophysiology of human multiple myeloma: therapeutic applications.

In this study we demonstrate that tumor necrosis factor alpha (TNFalpha) triggers only modest proliferation, as well as p44/p42 mitogen-activated protein kinase (MAPK) and NF-kappaB activation, in MM.1S multiple myeloma (MM) cells. TNFalpha also activates NF-kappaB and markedly upregulates (fivefold) secretion of interleukin-6 (IL-6), a myeloma growth and survival factor, in bone marrow stromal cells (BMSCs). TNFalpha in both a dose and time dependent fashion induced expression of CD11a (LFA-1), CD54 (intercellular adhesion molecule-1, ICAM-1), CD106 (vascular cell adhesion molecule-1, VCAM-1), CD49d (very late activating antigen-4, VLA-4), and/or MUC-1 on MM cell lines; as well as CD106 (VCAM-1) and CD54 (ICAM-1) expression on BMSCs. This resulted in increased (2-4-fold) per cent specific binding of MM cells to BMSCs, with related IL-6 secretion. Importantly, the proteasome inhibitor PS-341 abrogated TNFalpha-induced NF-kappaB activation, induction of ICAM-1 or VCAM-1, and increased adhesion of MM cells to BMSCs. Agents which act to inhibit TNFalpha may therefore abrogate the paracrine growth and survival advantage conferred by MM cell adhesion in the BM microenvironment.

Antigens, CD↗

PubMed2001

Vascular endothelial growth factor triggers signaling cascades mediating multiple myeloma cell growth and migration.

Multiple myeloma (MM) remains incurable, with a median survival of 3 to 4 years. This study shows direct effects of vascular endothelial growth factor (VEGF) upon MM and plasma cell leukemia (PCL) cells. The results indicate that VEGF triggers tumor cell proliferation via a protein kinase C (PKC)-independent Raf-1-MEK-extracellular signal-regulated protein kinase pathway, and migration via a PKC-dependent pathway. These observations provide the framework for novel therapeutic strategies targeting VEGF signaling cascades in MM.

Cell Division↗

PubMed2001

Thalidomide and immunomodulatory derivatives augment natural killer cell cytotoxicity in multiple myeloma.

The antiangiogenic activity of thalidomide (Thal), coupled with an increase in bone marrow angiogenesis in multiple myeloma (MM), provided the rationale for the use of Thal in MM. Previously, the direct anti-MM activity of Thal and its analogues (immunomodulatory drugs, IMiDs) on MM cells was demonstrated, suggesting multiple mechanisms of action. In this study, the potential immunomodulatory effects of Thal/IMiDs in MM were examined. It was demonstrated that Thal/IMiDs do not induce T-cell proliferation alone but act as costimulators to trigger proliferation of anti-CD3-stimulated T cells from patients with MM, accompanied by an increase in interferon-gamma and IL-2 secretion. However, an increase in autologous T-cell killing of patient MM cells could not be demonstrated. A role for natural killer (NK)- and LAK-cell-mediated killing is suggested because IL-2-primed peripheral blood mononuclear cells (PBMCs) treated with Thal/IMiDs demonstrated significantly increased lysis of MM cell lines. Cold target inhibition assays suggested NK- rather than LAK-cell-mediated killing. Furthermore, this killing was not major histocompatibility complex-class restricted, and the depletion of CD56(+) cells blocked the drug-induced MM cell lysis. It was significant that increased killing of patient MM cells by autologous PBMCs treated with Thal/IMiDs was also observed. Although the in vivo relevance of NK-cell-mediated MM cell killing is unknown, phenotypic analysis performed in MM patients receiving Thal therapy demonstrated an increase in CD3(-)CD56(+) cells in patients responding to therapy. Thus in vitro and in vivo data support the hypothesis that Thal may mediate its anti-MM effect, at least in part, by modulating NK cell number and function.

Adjuvants, Immunologic↗

PubMed2001

Single neurons in prefrontal cortex encode abstract rules.

The ability to abstract principles or rules from direct experience allows behaviour to extend beyond specific circumstances to general situations. For example, we learn the 'rules' for restaurant dining from specific experiences and can then apply them in new restaurants. The use of such rules is thought to depend on the prefrontal cortex (PFC) because its damage often results in difficulty in following rules. Here we explore its neural basis by recording from single neurons in the PFC of monkeys trained to use two abstract rules. They were required to indicate whether two successively presented pictures were the same or different depending on which rule was currently in effect. The monkeys performed this task with new pictures, thus showing that they had learned two general principles that could be applied to stimuli that they had not yet experienced. The most prevalent neuronal activity observed in the PFC reflected the coding of these abstract rules.

Animals↗

PubMed2001

Apaf-1/cytochrome c-independent and Smac-dependent induction of apoptosis in multiple myeloma (MM) cells.

Smac, a second mitochondria-derived activator of caspases, promotes caspase activation in the cytochrome c (cyto-c)/Apaf-1/caspase-9 pathway. Here, we show that treatment of multiple myeloma (MM) cells with dexamethasone (Dex) triggers the release of Smac from mitochondria to cytosol and activates caspase-9 without concurrent release of cyto-c and Apaf-1 oligomerization. Smac binds to XIAP (an inhibitor of apoptosis protein) and thereby, at least in part, eliminates its inhibitory effect on caspase-9. Interleukin-6, a growth factor for MM, blocks Dex-induced apoptosis and prevents release of Smac. Taken together, these findings demonstrate that Smac plays a functional role in mediating Dex-induced caspase-9 activation and apoptosis in MM cells.

Apoptosis↗

PubMed2001

The proteasome inhibitor PS-341 inhibits growth, induces apoptosis, and overcomes drug resistance in human multiple myeloma cells.

Human multiple myeloma (MM) is a presently incurable hematological malignancy, and novel biologically based therapies are urgently needed. Proteasome inhibitors represent a novel potential anticancer therapy. In this study, we demonstrate that the proteasome inhibitor PS-341 directly inhibits proliferation and induces apoptosis of human MM cell lines and freshly isolated patient MM cells; inhibits mitogen-activated protein kinase growth signaling in MM cells; induces apoptosis despite induction of p21 and p27 in both p53 wild-type and p53 mutant MM cells; overcomes drug resistance; adds to the anti-MM activity of dexamethasone; and overcomes the resistance to apoptosis in MM cells conferred by interleukin-6. PS-341 also inhibits the paracrine growth of human MM cells by decreasing their adherence to bone marrow stromal cells (BMSCs) and related nuclear factor kappaB-dependent induction of interleukin-6 secretion in BMSCs, as well as inhibiting proliferation and growth signaling of residual adherent MM cells. These data, therefore, demonstrate that PS-341 both acts directly on MM cells and alters cellular interactions and cytokine secretion in the BM millieu to inhibit tumor cell growth, induce apoptosis, and overcome drug resistance. Given the acceptable animal and human toxicity profile of PS-341, these studies provide the framework for clinical evaluation of PS-341 to improve outcome for patients with this universally fatal hematological malignancy.

Antineoplastic Agents↗

PubMed2001

Platelet transfusion for patients with cancer: clinical practice guidelines of the American Society of Clinical Oncology.

OBJECTIVE: To determine the most effective, evidence-based approach to the use of platelet transfusions in patients with cancer. OUTCOMES: Outcomes of interest included prevention of morbidity and mortality from hemorrhage, effects on survival, quality of life, toxicity reduction, and cost-effectiveness. EVIDENCE: A complete MedLine search was performed of the past 20 years of the medical literature. Keywords included platelet transfusion, alloimmunization, hemorrhage, threshold and thrombocytopenia. The search was broadened by articles from the bibliographies of selected articles. VALUES: Levels of evidence and guideline grades were rated by a standard process. More weight was given to studies that tested a hypothesis directly related to one of the primary outcomes in a randomized design. BENEFITS/HARMS/COST: The possible consequences of different approaches to the use of platelet transfusion were considered in evaluating a preference for one or another technique producing similar outcomes. Cost alone was not a determining factor. RECOMMENDATIONS: Appendix A summarizes the recommendations concerning the choice of particular platelet preparations, the use of prophylactic platelet transfusions, indications for transfusion in selected clinical situations, and the diagnosis, prevention, and management of refractoriness to platelet transfusion. VALIDATION: Five outside reviewers, the ASCO Health Services Research Committee, and the ASCO Board reviewed this document. SPONSOR: American Society of Clinical Oncology

Cost-Benefit Analysis↗

PubMed2001

CD6+ donor marrow T-cell depletion as the sole form of graft-versus-host disease prophylaxis in patients undergoing allogeneic bone marrow transplant from unrelated donors.

PURPOSE: The role of donor marrow T-cell depletion (TCD) in preventing graft-versus-host disease (GVHD) after transplantation of unrelated allogeneic marrow remains undefined. Because different TCD methodologies differ in the degree and specificity with which T cells are removed, it is likely that transplant outcomes would depend on which technique is used. Herein, we report results in the first 48 recipients of unrelated marrow using CD6+ TCD as the sole form of GVHD prophylaxis. PATIENTS AND METHODS: Median age of patients was 46 years (20 to 58 years). Donors were matched at A/B HLA loci. Ablation consisted of cyclophosphamide and fractionated total-body irradiation (TBI; 14 Gy). To facilitate engraftment, patients also received 7.5 Gy (22 patients) [corrected] or 4.5 Gy (26 patients) [corrected] of total lymphoid irradiation (TLI) before admission. No additional immune suppressive prophylaxis was administered. Granulocyte colony-stimulating factor was administered daily from day +1 to engraftment. RESULTS: All 48 patients demonstrated neutrophil engraftment. An absolute neutrophil count of 500 x 10(6)/L was achieved at a median of 12 days (range, 9 to 23 days). There were no cases of late graft failure. The number of CD34+ cells infused/kg was associated with speed of platelet and neutrophil recovery. The dose of TLI did not influence engraftment. Grades 2-4 acute GVHD occurred in 42% of patients (95% confidence interval [CI], 0.28 to 0.57). Mortality at day 100 was 19%. There have been only five relapses. Estimated 2-year survival was 44% (95% CI, 0.28 to 0.59) for the entire group, 58% for patients less than 50 years of age. In multivariable analysis, age less than 50 years (P =.002), cytomegalovirus seronegative status (P =.04), and early disease status at bone marrow transplant (P =.05) were associated with superior survival. CONCLUSION: CD6+ TCD does not impede engraftment of unrelated bone marrow after low-dose TLI, cyclophosphamide, and TBI. CD6+ TCD as the sole form of GVHD prophylaxis results in an incidence of GVHD that compares favorably with many adult studies of unrelated transplantation using unmanipulated marrow and immune-suppressive medications, especially in light of the median age of our patients (46 years). Although event-free survival in patients less than 50 years of age is very encouraging, older patients experience frequent transplantation-related complications despite TCD.

Adult↗

PubMed2001

Targeted therapy for multiple myeloma.

Multiple myeloma (MM) remains incurable with conventional treatment approaches, and novel biologically based therapies are therefore urgently needed. Targeted therapies are either under development or already undergoing clinical evaluation predicated upon: identifying genetic abnormalities in myeloma cells to enhance chemoradiosensitivity; interrupting growth or triggering apoptotic signaling cascades in tumor cells; treating both the tumor cell and its microenvironment; enhancing allogeneic and autologous antimyeloma immunity; and characterizing new myeloma antigens for serotherapy. These therapies, alone or in combination with conventional treatments, offer great promise to improve the outcome for patients with MM.

Antigens, Neoplasm↗

PubMed2001

Multiple Myeloma. Advances in disease biology: therapeutic implications.

The survival and proliferation of multiple myeloma cells are largely dependent on a supportive microenvironment. Interleukin-6 (IL-6) is known for its ability to support cell growth and prevent apoptosis, and clinical trials using monoclonal antibodies to block IL-6 or its receptors are underway. Apoptosis of myeloma cells triggered by corticosteroids is mediated by related focal adhesion tyrosine kinase (RAFTK); blocking RAFTK inhibits this apoptosis-inducing effect IL-6 activates SHP2, which inhibits RAFTK activation, thereby protecting multiple myeloma cells from the apoptotic effects of corticosteroids. Therefore, SHP2 and RAFTK might be appropriate targets for therapeutic interventions in multiple myeloma. Angiogenesis is also prominent in the pathogenesis of multiple myeloma. Vascular endothelial growth factor (VEGF) is one of the important endogenous factors that promote angiogenesis. An understanding of the process of angiogenesis in myeloma is necessary, because its inhibition offers promising prognostic and therapeutic implications. Thalidomide has recently been found to have both antiangiogenic and immunostimulating effects, and may be an important new antimyeloma agent. Immune-based therapies will likely play an increasing role in the treatment of multiple myeloma, and novel approaches are directed to generating immune responses to specific multiple myeloma antigens.

Antibodies↗

PubMed2001

A pilot study of combined immunotherapy with autologous adoptive tumour-specific T-cell transfer, vaccination with CD40-activated malignant B cells and interleukin 2.

Most B-cell malignancies are incurable diseases and therefore warrant new therapeutic approaches. In a pilot study, we tested the feasibility and safety of combined immunotherapy consisting of adoptive transfer of autologous tumour-specific T cells, low-dose interleukin 2 (IL-2) and a cellular vaccine of CD40-activated plasma cell leukaemia (PCL) cells in a patient who failed tandem repeat stem cell transplantation and idiotype vaccination. Autologous tumour-specific T cells for adoptive T-cell transfer were propagated in vitro by repetitive stimulation with autologous ex vivo CD40-activated PCL cells. CD40-activated PCL cells for vaccination were similarly generated ex vivo by co-culture with CD40 ligand transfectants. Autologous T cells (5 x 108 and 2.5 x 109 for two separate treatment cycles) generated ex vivo and cytotoxic against autologous tumours were infused and well tolerated by the patient. Fever and myalgias were closely related to IL-2 injections and no other adverse effects were observed. A temporary decrease of PCL cells in peripheral blood was seen after the first cycle of adoptive T-cell therapy, tumour cell vaccination and low-dose IL-2. Tumour progression was associated with tumour cells that (1) expressed a complex karyotype, (2) demonstrated loss of MHC class II, and (3) did not induce autologous tumour-specific T-cell lines ex vivo. We demonstrated the safety and feasibility in combining autologous tumour-specific T-cell therapy with low-dose IL-2 and that clinical trials based on the use of CD40-activated autologous tumour cell vaccines are warranted in patients with CD40-activated autologous tumour cells, either as a vaccine or for ex vivo stimulation of autologous T cells.

Adoptive Transfer↗

PubMed2001

History of the development of arsenic derivatives in cancer therapy.

Arsenic is a natural substance that has been used medicinally for over 2,400 years. In the 19th century, it was the mainstay of the materia medica. A solution of potassium arsenite (Fowler's solution) was used for a variety of systemic illnesses from the 18th until the 20th century. This multipurpose solution was also primary therapy for the treatment of chronic myelogenous leukemia until replaced by radiation and cytotoxic chemotherapy. The past 100 years have seen a precipitous decline in arsenic use and, by the mid-1990s, the only recognized indication was the treatment of trypanosomiasis. Much of this decline was due to concerns about the toxicity and potential carcinogenicity of chronic arsenic administration. The rebirth of arsenic therapy occurred in the 1970s when physicians in China began using arsenic trioxide as part of a treatment for acute promyelocytic leukemia (APL). Their accumulated experience showed that a stable solution of arsenic trioxide given by intravenous infusion was remarkably safe and effective both in patients with newly diagnosed APL leukemia and in those with refractory and relapsed APL. The mechanisms of action of arsenic derivatives in this disease and other malignancies are many and include induction of apoptosis, partial cytodifferentiation, inhibition of proliferation, and inhibition of angiogenesis. Molecular studies and ongoing clinical trials suggest that, as a chemotherapeutic agent, arsenic trioxide shows great promise in the treatment of malignant disease.

Antineoplastic Agents↗

PubMed2000

Ku86 variant expression and function in multiple myeloma cells is associated with increased sensitivity to DNA damage.

Ku is a heterodimer of Ku70 and Ku86 that binds to double-stranded DNA breaks (DSBs), activates the catalytic subunit (DNA-PKcs) when DNA is bound, and is essential in DSB repair and V(D)J recombination. Given that abnormalities in Ig gene rearrangement and DNA damage repair are hallmarks of multiple myeloma (MM) cells, we have characterized Ku expression and function in human MM cells. Tumor cells (CD38(+)CD45RA(-)) from 12 of 14 (86%) patients preferentially express a 69-kDa variant of Ku86 (Ku86v). Immunoblotting of whole cell extracts (WCE) from MM patients shows reactivity with Abs targeting Ku86 N terminus (S10B1) but no reactivity with Abs targeting Ku86 C terminus (111), suggesting that Ku86v has a truncated C terminus. EMSA confirmed a truncated C terminus in Ku86v and further demonstrated that Ku86v in MM cells had decreased Ku-DNA end binding activity. Ku86 forms complexes with DNA-PKcs and activates kinase activity, but Ku86v neither binds DNA-PKcs nor activates kinase activity. Furthermore, MM cells with Ku86v have increased sensitivity to irradiation, mitomycin C, and bleomycin compared with patient MM cells or normal bone marrow donor cells with Ku86. Therefore, this study suggests that Ku86v in MM cells may account for decreased DNA repair and increased sensitivity to radiation and chemotherapeutic agents, whereas Ku86 in MM cells confers resistance to DNA damaging agents. Coupled with a recent report that Ku86 activity correlates with resistance to radiation and chemotherapy, these results have implications for the potential role of Ku86 as a novel therapeutic target.

Antigens, Nuclear↗

PubMed2000

Thalidomide and its analogs overcome drug resistance of human multiple myeloma cells to conventional therapy.

Although thalidomide (Thal) was initially used to treat multiple myeloma (MM) because of its known antiangiogenic effects, the mechanism of its anti-MM activity is unclear. These studies demonstrate clinical activity of Thal against MM that is refractory to conventional therapy and delineate mechanisms of anti-tumor activity of Thal and its potent analogs (immunomodulatory drugs [IMiDs]). Importantly, these agents act directly, by inducing apoptosis or G1 growth arrest, in MM cell lines and in patient MM cells that are resistant to melphalan, doxorubicin, and dexamethasone (Dex). Moreover, Thal and the IMiDs enhance the anti-MM activity of Dex and, conversely, are inhibited by interleukin 6. As for Dex, apoptotic signaling triggered by Thal and the IMiDs is associated with activation of related adhesion focal tyrosine kinase. These studies establish the framework for the development and testing of Thal and the IMiDs in a new treatment paradigm to target both the tumor cell and the microenvironment, overcome classical drug resistance, and achieve improved outcome in this presently incurable disease.

Antineoplastic Agents↗

PubMed2000

Elevated soluble MUC1 levels and decreased anti-MUC1 antibody levels in patients with multiple myeloma.

Soluble MUC1 (sMUC1) levels are elevated in many MUC1(+) cancers. We and others have shown that MUC1 is expressed on multiple myeloma (MM) plasma cells and B cells. In this study, we measured sMUC1 levels in bone marrow (BM) plasma from 71 MM patients and 21 healthy donors (HDs), and in peripheral blood (PB) plasma from 42 MM patients and 13 HDs using an immunoassay that detects the CA27.29 epitope of MUC1. sMUC1 levels were found to be significantly greater (mean 31.76 U/mL, range 5.69 to 142.48 U/mL) in MM patient BM plasma versus HD BM plasma (mean 9.68 U/mL, range 0.65 to 39.83 U/mL) (P <. 001). Importantly, BM plasma sMUC1 levels were related to tumor burden because sMUC1 levels were significantly higher for MM patients with active disease (34.62 U/mL, range 5.69 to 142.48 U/mL) versus MM patients with minimal residual disease (16.16 U/mL, range 5.7 to 56.68 U/mL) (P =.0026). sMUC1 levels were also elevated in the PB plasma of MM patients (32.79 U/mL, range 4.15 to 148.84 U/mL) versus HDs (18.47 U/mL, range 8.84 to 42.49) (P =.0052). Lastly, circulating immunglobulin M (IgM) and IgG antibodies to MUC1 were measured in 114 MM patients and 31 HDs, because natural antibodies to MUC1 have been detected in patients with other MUC1-bearing malignancies. These studies demonstrated lower levels of circulating IgM (P <.001) and IgG (P =.078) antibodies to MUC1 in MM patients compared with HDs. Our data therefore show that in MM patients, sMUC1 levels are elevated and correlate with disease burden, whereas anti-MUC1 antibody levels are decreased.

Autoantibodies↗