Anti-TGF-β/PD-L1 bispecific antibody promotes T cell infiltration and exhibits enhanced antitumor activity in triple-negative breast cancer

BACKGROUND

Agents blocking programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) have been approved for triple-negative breast cancer (TNBC). However, the response rate of anti-PD-1/PD-L1 is still unsatisfactory, partly due to immunosuppressive factors such as transforming growth factor-beta (TGF-β). In our previous pilot study, the bispecific antibody targeting TGF-β and murine PD-L1 (termed YM101) showed potent antitumor effect. In this work, we constructed a bispecific antibody targeting TGF-β and human PD-L1 (termed BiTP) and explored the antitumor effect of BiTP in TNBC.

METHODS

BiTP was developed using Check-BODY^TM bispecific platform. The binding affinity of BiTP was measured by surface plasmon resonance, ELISA, and flow cytometry. The bioactivity was assessed by Smad and NFAT luciferase reporter assays, immunofluorescence, western blotting, and superantigen stimulation assays. The antitumor activity of BiTP was explored in humanized epithelial-mesenchymal transition-6-hPDL1 and 4T1-hPDL1 murine TNBC models. Immunohistochemical staining, flow cytometry, and bulk RNA-seq were used to investigate the effect of BiTP on immune cell infiltration.

RESULTS

BiTP exhibited high binding affinity to dual targets. In vitro experiments verified that BiTP effectively counteracted TGF-β-Smad and PD-L1-PD-1-NFAT signaling. In vivo animal experiments demonstrated that BiTP had superior antitumor activity relative to anti-PD-L1 and anti-TGF-β monotherapy. Mechanistically, BiTP decreased collagen deposition, enhanced CD8⁺ T cell penetration, and increased tumor-infiltrating lymphocytes. This improved tumor microenvironment contributed to the potent antitumor activity of BiTP.

CONCLUSION

BiTP retains parent antibodies' binding affinity and bioactivity, with superior antitumor activity to parent antibodies in TNBC. Our data suggest that BiTP might be a promising agent for TNBC treatment.

Immune and Genetic Signatures of Breast Carcinomas Triggering Anti-Yo–Associated Paraneoplastic Cerebellar Degeneration

Background and Objectives

Paraneoplastic cerebellar degeneration (PCD) with anti-Yo antibodies is a cancer-related autoimmune disease directed against neural antigens expressed by tumor cells. A putative trigger of the immune tolerance breakdown is genetic alteration of Yo antigens. We aimed to identify the tumors' genetic and immune specificities involved in Yo-PCD pathogenesis.

Methods

Using clinicopathologic data, immunofluorescence (IF) imaging, and whole-transcriptome analysis, 22 breast cancers (BCs) associated with Yo-PCD were characterized in terms of oncologic characteristics, genetic alteration of Yo antigens, differential gene expression profiles, and morphofunctional specificities of their in situ antitumor immunity by comparing them with matched control BCs.

Results

Yo-PCD BCs were invasive carcinoma of no special type, which early metastasized to lymph nodes. They overexpressed human epidermal growth factor receptor 2 (HER2) but were hormone receptor negative. All Yo-PCD BCs carried at least 1 genetic alteration (variation or gain in copy number) on CDR2L, encoding the main Yo antigen that was found aberrantly overexpressed in Yo-PCD BCs. Analysis of the differentially expressed genes found 615 upregulated and 54 downregulated genes in Yo-PCD BCs compared with HER2-driven control BCs without PCD. Ontology enrichment analysis found significantly upregulated adaptive immune response pathways in Yo-PCD BCs. IF imaging confirmed an intense immune infiltration with an overwhelming predominance of immunoglobulin G–plasma cells.

Discussion

These data confirm the role of genetic alterations of Yo antigens in triggering the immune tolerance breakdown but also outline a specific biomolecular profile in Yo-PCD BCs, suggesting a cancer-specific pathogenesis.

Monomethyl auristatin antibody and peptide drug conjugates for trimodal cancer chemo-radio-immunotherapy

Locally advanced cancers remain therapeutically challenging to eradicate. The most successful treatments continue to combine decades old non-targeted chemotherapies with radiotherapy that unfortunately increase normal tissue damage in the irradiated field and have systemic toxicities precluding further treatment intensification. Therefore, alternative molecularly guided systemic therapies are needed to improve patient outcomes when applied with radiotherapy. In this work, we report a trimodal precision cytotoxic chemo-radio-immunotherapy paradigm using spatially targeted auristatin warheads. Tumor-directed antibodies and peptides conjugated to radiosensitizing monomethyl auristatin E (MMAE) specifically produce CD8 T cell dependent durable tumor control of irradiated tumors and immunologic memory. In combination with ionizing radiation, MMAE sculpts the tumor immune infiltrate to potentiate immune checkpoint inhibition. Here, we report therapeutic synergies of targeted cytotoxic auristatin radiosensitization to stimulate anti-tumor immune responses providing a rationale for clinical translational of auristatin antibody drug conjugates with radio-immunotherapy combinations to improve tumor control.

Radiotheranostic Agents in Hematological Malignancies

Radioimmunotherapy (RIT) is a cancer treatment that combines radiation therapy with tumor-directed monoclonal antibodies (Abs). Although RIT had been introduced for the treatment of CD20 positive non-Hodgkin lymphoma decades ago, it never found a broad clinical application. In recent years, researchers have developed theranostic agents based on Ab fragments or small Ab mimetics such as peptides, affibodies or single-chain Abs with improved tumor-targeting capacities. Theranostics combine diagnostic and therapeutic capabilities into a single pharmaceutical agent; this dual application can be easily achieved after conjugation to radionuclides. The past decade has seen a trend to increased specificity, fastened pharmacokinetics, and personalized medicine. In this review, we discuss the different strategies introduced for the noninvasive detection and treatment of hematological malignancies by radiopharmaceuticals. We also discuss the future applications of these radiotheranostic agents.

Paraneoplastic Cerebellar Degeneration With P/Q-VGCC vs Yo Autoantibodies

BACKGROUND AND OBJECTIVES

Paraneoplastic cerebellar degeneration (PCD) is characterized by a widespread loss of Purkinje cells (PCs) and may be associated with autoantibodies against intracellular antigens such as Yo or cell surface neuronal antigens such as the P/Q-type voltage-gated calcium channel (P/Q-VGCC). Although the intracellular location of the target antigen in anti-Yo-PCD supports a T cell-mediated pathology, the immune mechanisms in anti-P/Q-VGCC-PCD remain unclear. In this study, we compare neuropathologic characteristics of PCD with anti-P/Q-VGCC and anti-Yo autoantibodies in an archival autopsy cohort.

METHODS

We performed neuropathology, immunohistochemistry, and multiplex immunofluorescence on formalin-fixed and paraffin-embedded brain tissue of 1 anti-P/Q-VGCC, 2 anti-Yo-PCD autopsy cases and controls.

RESULTS

Anti-Yo-PCD revealed a diffuse and widespread PC loss together with microglial nodules with pSTAT1+ and CD8+granzymeB+ T cells and neuronal upregulation of major histocompatibility complex (MHC) Class I molecules. Some neurons showed a cytoplasmic immunoglobulin G (IgG) staining. In contrast, PC loss in anti-P/Q-VGCC-PCD was focal and predominantly affected the upper vermis, whereas caudal regions and lateral hemispheres were spared. Inflammation was characterized by scattered CD8+ T cells, single CD20+/CD79a+ B/plasma cells, and an IgG staining of the neuropil in the molecular layer of the cerebellar cortex and neuronal cytoplasms. No complement deposition or MHC-I upregulation was detected. Moreover, synaptophysin was reduced, and neuronal P/Q-VGCC was downregulated. In affected areas, axonal spheroids and the accumulation of amyloid precursor protein and glucose-regulated protein 78 in PCs indicate endoplasmatic reticulum stress and impairment of axonal transport. In both PCD types, calbindin expression was reduced or lost in the remaining PCs.

DISCUSSION

Anti-Yo-PCD showed characteristic features of a T cell-mediated pathology, whereas this was not observed in 1 case of anti-P/Q-VGCC-PCD. Our findings support a pathogenic role of anti-P/Q-VGCC autoantibodies in causing neuronal dysfunction, probably due to altered synaptic transmission resulting in calcium dysregulation and subsequent PC death. Because disease progression may lead to irreversible PC loss, anti-P/Q-VGCC-PCD patients could benefit from early oncologic and immunologic therapies.

Rare Breast Carcinoma with Paradoxical Plasma Cell Immunoprofile: A Case Report

Plasma cell features are encountered in a variety of non-plasma cell neoplasias, especially carcinomas of a discohesive type, such as those occurring in the digestive tract and breast. Lobular carcinomas of the breast present themselves in a variety of architectural patterns and many cell morphologies, including plasmacytoid types. A matching plasma cell phenotype is sometimes an associated feature. We report a case of a moderate grade invasive lobular carcinoma with focal plasmacytoid morphology and aberrant expression of plasma cell markers in a patient previously diagnosed with multiple myeloma. Paradoxical plasma cell immunoprofiles can be encountered in many malignancies, causing serious diagnostic problems, even more so with those occurring in discohesive carcinomas in multiple myeloma patients.

Tomato lectin-modified nanoemulsion-encapsulated MAGE1-HSP70/SEA complex protein vaccine: Targeting intestinal M cells following peroral administration

Vaccines administered orally enable the stimulation of both the mucous membrane and system immune responses. However, tumor vaccines, whose effective elements are antigen protein molecules or gene-encoding antigens, are hardly accustomed to the harsh gastrointestinal environment. Here, we explored an oral nanoecapsulated tumor vaccine complex to evaluate the anti-tumor effect. Tomato lectin (TL) was modified on the surface of a nanoemulsion (NE) composed of MAGE1-HSP70/SEA (MHS). C57BL/6 mice were immunized with NE (-), NE (MHS) and TL-NE (MHS) via po. or sc. administration. Additionally, the cellular immunocompetence was detected by the enzyme-linked immunospot assay and lactate dehydrogenase release assay. Serum antibody titers were analyzed using the enzyme-linked immuno sorbent assay. Next, the therapeutic and tumor challenge assays were performed. The TL-NE (MHS) particles were 20 ± 5 nm in diameter and could resist pepsin and trypsin digestion. The cellular immune responses elicited by TL-NE (MHS) perioral were stronger than those by TL-NE (MHS)-sc. (p < 0.05) when targeted to B16-MAGE1 tumor cells. The levels of MAGE-1 antibody induced by TL-NE (MHS) via the oral route was higher than control group (p < 0.05). The percentage of CD4+ and CD8+ T cells in TL-NE (MHS)-po. group was more than other groups (p < 0.05). Furthermore, oral TL-NE (M)HScould delay tumor growth and defer tumor occurrence and tumor recurrence after resection in mice challenged with B16-MAGE-1 tumor cells. The study suggested that the oral TL-NE (MHS) vaccine delivery system is feasible to improve the vaccine protection effect and may have broad application in cancer therapy.

Accessibility of Antigenic Sites Recognized by AUA1, HMFG1 and HMFG2 Monoclonal Antibodies: Its Influence on Antibody Binding of Live Cells

We assessed the immunoreactivity of live and alcohol-fixed monolayers of HRA-19, a rectal adenocarcinoma cell line, to the monoclonal antibodies AUA1, HMFG1 and HMFG2. Differences in staining patterns between live and alcohol-fixed colonies were found. The well-polarized cells forming the centers of the monolayer colonies showed strong membrane staining when the cells were alcohol-fixed prior to AUA1 incubation, but showed no staining when the cells were alive during the incubation. When AUA1 incubation was done both before and after alcohol fixation, membrane staining was again seen, ruling out the possibility of antigenic modulation. Incubation of live cells with AUA1 together with EDTA showed strong staining of dissociating cells. It is concluded that AUA1 antigenic sites, which on polarized cells are basolateral in location, are inaccessible to the antibody-containing culture fluid, which bathes the apical aspects of the cells, but they become accessible after alcohol fixation, or treatment with EDTA.

HMFG1 antigenic sites are located on the apical cell membrane, and accordingly, no differences were seen between incubation of live and alcohol-fixed cells when incubated with HMFG1. The antigenic sites of HMFG2 are partly intracellular, and in our monolayer model, the staining of live cells was weaker and more scarce than on alcohol-fixed cells. It is concluded that immunostaining of cytological and histological material of tumours may not adequately predict antibody binding on live cells, and thus, these findings are of importance in the context of selection of monoclonal antibodies for clinical radio-immunotargeting.

Nature and Properties of C3Hf Natural Antitumor Cytotoxins Directed against Murine Lymphosarcoma Cells

The nature and some biological properties of the natural antitumor cytotoxins previously found in normal C3Hf serum, have been investigated. By immunoelectronmicroscopy study, employing rabbit hybrid antibodies with specificity for mouse Ig and ferritin, the C3Hf cytotoxins were shown to belong to immunoglobulins. By gel filtration, by inhibition experiments of the cytotoxic serum activity with monospecific anti-IgG and anti-IgM sera, and by 2-mercaptoethanol treatment of the C3Hf serum, the cytotoxic immunoglobulins were demonstrated to belong to the IgM class. They were not inactivated by heating until 60 °C and were able to activate guinea pig, rabbit, and human complement. The highest cytotoxic activity of the normal C3Hf serum was found when cells and serum were incubated at the low temperature, suggesting a low binding affinity of the cytotoxic IgM.

Primary Central Nervous System Lymphomas: Clinicopathologic and Immunohistochemical Analysis of 30 Cases

Aims and background

Primary Central Nervous System lymphomas are attracting mounting interest because of their increasing incidence in an immunocompetent population and as sporadic tumors. A new lymphoma classification has been proposed, based on new morphologic entities and on advanced immunonologic and molecular techniques.

Methods and Results

The study concerns the clinical and pathologic characterization of 30 cases of primary central nervous system non-Hodgkin's lymphomas in non-HIV patients using a wide monoclonal antibodies panel. Comparative evaluation of effectiveness and reliability between surgery and stereotactic biopsies was made according to Kiel and Real lymphoma classifications. There were 24 high-grade and only 3 low-grade lymphomas. Three stereotactic biopsies were not diagnostic.

Conclusions

Stereotactic procedures were confirmed as the most immediate and least aggressive approach to CNS tumors, but inadequate sampling caused a deadlock to a full lymphoma diagnosis, which requires immunohistochemical and sometimes also molecular studies. However, it should be stressed that morphologic criteria (tumor cell cytology and neoplastic cuffing of the vascular walls) maintain their diagnostic effectiveness.

Reactivity of Polyclonal and Two Monoclonal Antibodies with Cell Subsets Isolated from Cystic Fluids of Ovarian Serous Neoplasms

The distribution of antigenic determinants on a cellular level in serous ovarian neoplasms was evaluated using polyclonal and two monoclonal antibodies (OC 125 and 10B). The expression of antigens was estimated by an immunofluorescence test on each cell fraction isolated by density centrifugation from cystic fluids of individual malignant and benign ovarian tumors, taking into account the density and cytomorphologic features of cell subpopulations. It was found that the studied antibodies recognized different antigenic determinants. Significant immunologic heterogeneity of cells among and within individual tumors was shown. Our studies show the value of isolated cell subpopulations for comparing the reactivity of different antibodies and estimating their immunodiagnostic potency.

Antigenic Proteins of Nucleolar Chromatin of Novikoff Hepatoma Ascites Cells

Nucleolar chromatin of Novikoff hepatoma ascites cells contains an antigen (no-Ag1) detected with antinucleolar antibodies by the immunodiffusion technique. This antigen was distinguished from the previously reported nuclear chromatin antigen NAg-1 (19) by the findings that tumor nucleolar antibodies which formed immunoprecipitin bands with no-Ag1 did not do so with NAg-1 and that tumor cytosol, which contains NAg-1, formed immunoprecipitin bands with tumor chromatin antibodies but not with antibodies to tumor nucleoli. Tumor nucleolar chromatin contains both NAg-1 and no-Ag1, but only no-Ag1 formed bands with tumor nucleolar antibodies. no-Ag1 is a component of tumor nucleolar chromatin that was not soluble in 0.075 M NaCl - 0.025 M EDTA, pH 8, and only slightly soluble in 0.01 M Tris-HCl, pH 8. no-Ag1 was not found in liver nucleoli. Antibodies to liver nucleoli formed immunoprecipitin bands with liver nucleolar antigens but none were confluent with those formed between tumor nucleolar antibodies and antigens of tumor nucleolar chromatin. Absorption of the tumor nucleolar antibodies with whole tumor cells or whole liver pressate did not alter band formation with no-Ag1. Three antigens in liver nucleoli were not found in tumor nucleoli.

Analysis of Rabbit and Guinea PIG Complement Efficiency in Cytotoxicity Tests against Fibrosarcoma and Lymphosarcoma Cells

In a complement-dependent 51Cr cytotoxicity assay, using as target murine fibrosarcoma or lymphosarcoma cells, the rabbit complement (RC) was more efficient than guinea pig complement (GPC) when tested either with strong antisera, such as anti-histocompatibility sera, or with weak sera, such as sera from normal mice shown previously to possess a natural antitumor response. The high efficiency of RC was not due to activation by antibodies of a different class or specificity than those activating GPC. In fact, both 2-mercaptoethanol (2-Me)-sensitive or-resistant immunoglobulins could activate both RC and GPC, and the results of absorption tests indicated that the antibodies detected using either of the 2 complements were directed against the same specificities. In addition, the results of tests searching for cooperative antibodies excluded that a cooperative effect might be responsible for the high efficiency of RC. With weak antisera, sera of different rabbits were found to have different complement activity.

Radiolabelled Stripped Mucin, SM3, Monoclonal Antibody for Immunoscintigraphy of Ovarian Tumours

A new monoclonal antibody, SM3, against stripped mucin core protein has been evaluated for the radioimmunoscintigraphy of ovarian cancer. It was radiolabelled with In-111, I-123 and Tc-99m and results showed a sensitivity of 95%, 100% and 100% and an accuracy of 73%, 86% and 100% for malignancy; respectively.

Neuroendocrine Carcinoma of the Skin (Merkel Cell Carcinoma): Immunocytochemical Study of a Case

The immunocytochemical phenotype was evaluated in a case of Merkel cell carcinoma of the skin. Intermediate filaments, i.e. neurofilament, glial fibrillary acid protein, cytokeratins, keratin and panfilament as well as S-100 protein, calcitonin and epithelial membrane antigen were detected by immunoperoxidase methods. Nodular positivity for neurofilament was observed. The remaining intermediate filaments and other markers were negative. Thus the origin of Merkel cell carcinoma appears uncertain and this tumor probably has neuroendocrine activity.

Significance of CA 72.4 Serum Levels in Gastrointestinal Diseases

In order to evaluate the usefulness of Ca 72.4 tumor associated antigen assay in gastrointestinal diseases, we have studied 751 patients suffering from benign (376) and neoplastic (375) digestive diseases and 305 normal controls. The cut-off point was fixed at 6 U/ml. The Ca 72.4 assay, with the proposed method, provides additional information only in gastric cancers; the positivity of the marker in gastric neoplasms is 38.4% and the specificity vs gastric ulcers and atrophic gastritis is 99%. In six patients with gastric cancer, the Ca 72.4 is the only positive test. The most striking observation to be made from the current study is a no good sensitivity of the marker for gastrointestinal cancers (29.6% vs 35.7 and 37.6% for CEA and Ca 19-9 respectively), but rather the excellent specificity of the Ca 72.4 immunoassay with respect to beign gastrointestinal diseases (98.7%), vs values of specificity for CEA and Ca 19-9 of 94 and 92%. In conclusion, the high specificity of this marker for gastrointestinal neoplasms may be very interesting in follow-up studies. In fact, an elevation of serum levels of Ca 72.4 should always be taken seriously.

Evaluation of the Expression of Tissue DF-3 and MCA and the Corresponding Serum Values in Patients with Breast Carcinoma

Two specific monoclonal antibodies for breast tissue (DF3 and MCAb-12) and the corresponding tumor markers CA15-3 and MCA in serum have been evaluated in 50 patients with breast cancer and in 15 controls. The expression of these antigens in tissue was poorly correlated with the common prognostic parameters. Their presence in serum was associated with an altered distribution of the antigens in the cell. The expression of these antigens in tissue enables us to select patients for serological follow-up and to evaluate tumor differentiation from a functional point of view.

[The place of immunotherapy in plasma cell myeloma treatment]

Plasma cell myeloma is the second most common haematological malignancy. The therapy in this disease has changed dramatically in recent twenty years due to new drugs implementation such as proteasome inhibitors and immunomodulatory drugs. Scientists’ efforts made to better cognition of normal immune surveillance in myeloma led to the formulation of new treatment strategy including immune system involvement. Many of these therapies are being evaluated in clinical trials and the preliminary results are promising. Probably another time in the last year’s we may witness paradigm revision in the plasma cell myeloma therapy. In the article we present essential, in our opinion, immunotherapy methods in myeloma.

Salivary auto-antibodies as noninvasive diagnostic markers of oral cavity squamous cell carcinoma

BACKGROUND

Oral cavity squamous cell carcinoma (OSCC) is one of the most common cancers worldwide, and its incidence is still increasing. Approximately 50% of patients with OSCC die within 5 years after diagnosis, mostly ascribed to the fact that the majority of patients present advanced stages of OSCC at the time of diagnosis.

METHODS

To discover salivary biomarkers for ameliorating the detection of OSCC, herein, we developed a multiplexed bead-based platform to simultaneously detect auto-antibodies (auto-Abs) in salivary samples.

RESULTS

Compared with healthy individuals, the salivary levels of anti-p53, anti-survivin, anti-Hsp60, and anti-RPLP0 were significantly elevated in patients with OSCC. Noteworthily, the elevated levels of anti-p53, anti-survivin, and anti-Hsp60 were already observed in individuals with oral potentially malignant disorder. Moreover, the salivary levels of anti-p53, anti-survivin, anti-Hsp60, anti-RPLP0, and anti-CK8 were significantly elevated in patients with early-stage OSCC compared with those in healthy individuals. Most importantly, the use of a combined panel of salivary anti-p53, anti-survivin, anti-Hsp60, and anti-RPLP0 largely improves the detection of OSCC.

CONCLUSION

Collectively, our results reveal that the salivary auto-Abs are effective OSCC biomarkers and the four-auto-Ab panel provides a novel and practicable approach for OSCC screening.

IMPACT

This study provides the first evidence for the potential clinical application of salivary auto-Abs in OSCC diagnosis.

Erythematous nodular lesion on the chest of an infant

An 11-month-old girl presented with an erythematous nodule on the chest, which had been growing for 8 months. The tumor was composed of uniform polygonal and spindle-shaped cells, forming nodules and fascicles. The diagnosis of neurothekeoma was based upon the histology and immunohistochemistry.

Near-infrared fluorescence molecular imaging of ductal carcinoma in situ with CD44v6-specific antibodies in mice: a preclinical study

Purpose

The purpose of this study was to develop a molecular imaging technique using tracers specific for ductal carcinoma in situ (DCIS) to improve visualization and localization of DCIS during surgery. As CD44v6 is frequently expressed in DCIS, we used near-infrared fluorescently labeled CD44v6-targeting antibodies for detection of DCIS.

Procedure

Mice bearing orthotopically transplanted CD44v6-positive MCF10DCIS DCIS-like tumors and CD44v6-negative MDA-MB-231 control tumors were intravenously injected with IRDye800CW conjugated to CD44v6-specific antibodies or control IgGs. Noninvasive imaging was performed for 8 days postinjection, followed by intraoperative imaging. Antibody accumulation and intratumor distribution were examined.

Results

Maximum accumulation of CD44v6-specific antibodies was obtained 24 h postinjection. Maximum tumor-to-background ratio for MCF10DCIS tumors was 4.5 ± 0.2, compared to 1.4 ± 0.1 (control tumors, p = 0.006), and 1.7 ± 0.1 (control IgG, p = 0.014), for 8 days postinjection. Ex vivo, tumor-to-background ratios were comparable to those obtained by intraoperative imaging.

Conclusions

We show the applicability of noninvasive and intraoperative optical imaging of DCIS-like lesions in vivo using CD44v6-specific antibodies.

Assessment of p53 and HER-2/neu genes status and protein products in oral squamous cell carcinomas

Identification of the genes involved in tumor initiation and progression has led to development of new markers and generated targets for new drugs. This study aimed to evaluate p53 and HER-2/neu genes status of and their protein products in oral cancer patients. Tumor specimens from 116 cases diagnosed with oral squamous cell carcinoma were analyzed. P53 and HER-2/neu immunoreactivity were studied. FISH analysis was performed to elucidate p53 and HER-2/neu gene status. Male cases represented 84% of the group. The majority of cases were between 51-60 years and moderately differentiated oral carcinoma had an incidence of 58.6%. Thirty-four cases showed p53 overexpression, negative immunoreaction was observed in 16.37% of cases. 66.38% of cases had p53 deletion, with an increased rate observed in neoplasms of the tongue. Immunohistochemical analysis of HER-2/neu receptor protein revealed that 76.72% were negative, 5.17% had weak immunostaining, 14.65% had +2 score, the others had +3 score. 24.1% of cases were analyzed using FISH technique, of which 25% were without amplification, but with polysomy for chromosome 17. 18.1% of total cases were amplified, with the rate HER-2/neu:CEP17 higher than 2. Of the 77 cases with a single p53 allele, 20 associated HER-2/neu amplification, 31 had positive anti-HER-2/neu immunoreaction, but did not have HER-2/neu:CEP17 rate >2. There was a significant association between HER-2/neu amplification and deletion of a p53 allele. These results could justify more extensive research to assess p53 and HER-2/neu gene status as significant prognostic factors in oral cancers.

[Immunotherapy targeting the Wilms' tumor 1 gene product for patients with malignant brain tumors]

In this paper, we review the current status of immunotherapy targeting Wilms' tumor 1 (WT1) peptide in malignant brain tumors as well as in other hematological and solid malignancies. WT1 is expressed in various kinds of malignancies, and is involved in oncogenesis. The titers of antibodies against WT1 and the frequency of WT1-specific cytotoxic T lymphocytes (CTLs) were higher in cancer patients than in healthy donors, indicating that WT1 protein has immunogenic function. These findings provided us with a rationale for developing cancer immunotherapy that targets the WT1 peptide. Clinical trials of the WT1 peptide vaccination were initiated, and definite immunological and clinical responses were observed. The disease control rate of 57.1% was obtained especially in the case of recurrent glioblastomas, with a median progression-free survival period of 20.0 weeks and progression-free survival rate at 6 months of 33.3%. The trial showed that WT1 vaccination for malignant gliomas, which is generally believed to be an intractable disease, was safe and elicited a favorable clinical response. Further clinical studies of WT1 vaccination in patients with malignant gliomas as well as other cancers are warranted. An enhancement of the efficacy of WT1 vaccination can be expected with a combined treatment using the WT1-specific helper peptide or anti-cancer chemotherapeutic agents. Administration of WT1 vaccination along with other therapeutic modalities during initial treatment or in the case showing minimal residual disease may prolong the survival time of the cancer patients.

Progression of colorectal cancers correlates with overexpression and loss of polarization of expression of the htid-1 tumor suppressor

Recently, we identified htid-1, the human counterpart of the Drosophila tumor suppressor gene lethal(2)tumorous imaginal discs [l(2)tid], as a direct molecular ligand of the adenomatous polyposis coli (APC) tumor suppressor. The gene encodes three cytosolic (Tid50, Tid48 and Tid46) and three mitochondrial (Tid43, Tid40 and Tid38) proteins. In the colorectal epithelium the cytosolic forms hTid50/hTid48 interact under physiological conditions with the N-terminal region of APC. This complex which associates with additional proteins such as Hsp70, Hsc70, Actin, Dvl and Axin defines a novel physiological state of APC unrelated to beta-catenin degradation. Here we show that the expression of the genes htid-1 and APC was altered in colorectal tumors. These changes concerned both the localization and the expression level of all three htid-1 splice variants and of APC. Furthermore, we showed that the protein products of the two tumor suppressors co-localized in the basal and apical region of normal colon epithelia and that loss of differentiation capacity of colorectal cancers correlated with a shift in their expression patterns from compartmentalized to diffuse cytoplasmic. These findings support our hypothesis that the building of the multi-component complex mentioned above is associated with the maintenance of the polarity of cells and tissues. In addition, we provide evidence that colon cancer progression correlates with up-regulation of htid-1 and its ligand Hsp70. Since the Tid proteins are members of the DnaJ-like protein family, an essential component of the Hsp70/Hsc70 chaperone machinery, our findings describe a novel, causal link between the function of chaperone machines, APC-mediated Wg/Wnt signaling and tumor development.

Acute pharmacodynamic and antivascular effects of the vascular endothelial growth factor signaling inhibitor AZD2171 in Calu-6 human lung tumor xenografts

The vascular endothelial growth factor-A (VEGF-A) signaling pathway, a key stimulant of solid tumor vascularization, is primarily dependent on the activation of the endothelial cell surface receptor VEGF receptor-2 (VEGFR-2). AZD2171 is an oral, highly potent small-molecule inhibitor of VEGFR tyrosine kinase activity that inhibits angiogenesis and the growth of human tumor xenografts in vivo. Here, we show pharmacodynamic changes in VEGFR-2 phosphorylation induced by AZD2171. In mouse lung tissue, a single dose of AZD2171 at 6 mg/kg inhibited VEGF-A-stimulated VEGFR-2 phosphorylation by 87% at 2 h with significant inhibition (>or=60%) maintained to 24 h. To examine inhibition of VEGFR-2 phosphorylation in tumor vasculature by immunohistochemistry, a comprehensive assessment of antibodies to various phosphorylation sites on the receptor was undertaken. Antibodies to the phosphotyrosine epitopes pY1175/1173 and pY1214/1212 were found suitable for this application. Calu-6 human lung tumor xenografts, from mice receiving AZD2171 or vehicle treatment (p.o., once daily), were examined by immunohistochemistry. A significant reduction in tumor vessel staining of phosphorylated VEGFR-2 (pVEGFR-2) was evident within 28 h of AZD2171 treatment (6 mg/kg). This effect preceded a significant reduction in tumor microvessel density, which was detectable following 52 h of AZD2171 treatment. These data show that AZD2171 is a potent inhibitor of VEGFR-2 activation in vivo and suggest that AZD2171 delivers therapeutic benefit in Calu-6 tumors by targeting vessels dependent on VEGFR-2 signaling for survival. In addition, this work highlights the utility of measuring either pY1175/1173 or pY1214/1212 on VEGFR-2 as a pharmacodynamic marker of VEGFR-2 activation.

Clinical validation of breast cancer biomarkers using tissue microarray technology

The results of previous studies done in our laboratory on breast cancer gene expression profile, using DNA microarrays, led to the discovery of several genes associated with breast cancer progression. Further evaluation of these genes and their involvement at various stages of cancer progression required performance of immunohistochemistry on thousands of different tissue blocks. Tissue microarray (TMA) technology facilitates rapid translation of DNA microarrays results to clinical specimens by using immunohistochemical analysis of protein expression. DNA microarray analysis done in our laboratory showed a significantly higher expression of prostatic-specific antigen (PSA) in invasive ductal carcinomas as compared to ductal carcinoma in situ, a finding contrary to the previously published data for PSA immunoreactivity in breast carcinomas. To find out whether TMA strategy could be used to explore the expression of the candidate genes involved in the breast cancer progression, we constructed a breast cancer progression TMA. It consisted of 2 normal ductal epithelium, 8 ductal carcinoma in situ, 19 invasive ductal carcinomas, and 3 metastatic ductal carcinomas of breast in triplets. Two prostatic adenocarcinomas and 2 normal colons were used as positive and negative controls, respectively. We first used well-documented and well-tested markers, such as antibodies to estrogen receptor, progesterone receptor, and p53. Results of these 3 antibodies were according to the previously published data. To validate our result, we then used antibody to PSA and looked for the expression of this protein on breast cancer progression TMA. Except for the 2 positive controls all 98 cores were found to be negative for PSA expression highlighting the importance of validation studies for DNA microarray results.

Population pharmacokinetics of humanized monoclonal antibody HuCC49deltaCH2 and murine antibody CC49 in colorectal cancer patients

To predict the optimal time for surgery after antibody administration, the population pharmacokinetics of (125)I-HuCC49deltaCH2 and (125)I-CC49 were characterized in 55 patients with colorectal cancers. A 2-compartment linear model was used to fit the pharmacokinetic data. Model stability and performance were assessed using a visual predictive check procedure. Different clinical trial designs were evaluated by simulation in combination with Bayesian estimation method to predict the optimal time for surgery. The results showed that HuCC49deltaCH2 had 65% faster clearance from blood circulation and 24% shorter mean residence time than CC49. Population pharmacokinetic analysis identified body weight as the only covariate to explain between-subject variability in clearance, intercompartmental flow rate, and volume of distribution. Model predictions indicated a wide interval for the optimal time of surgery, suggesting that it would be beneficial to individualize the time of surgery for each patient by measurement of antibody disposition. Clinical trial designs with at least 3 measurements of antibody disposition were found to be better than an empirical direct observation method for the optimal prediction of surgery time.

Modulation of cancer cell survival pathways using multivalent liposomal therapeutic antibody constructs

Various methods have been explored to enhance antibody-based cancer therapy. The use of multivalent antibodies or fragments against tumor antigens has generated a great deal of interest, as various cellular signals, including induction of apoptosis, inhibition of cell growth/survival, or internalization of the surface molecules, can be triggered or enhanced on extensive cross-linking of the target/antibody complex by the multivalent form of the antibody. The goal of the studies reported here was to develop multivalent antibody constructs via grafting of antibody molecules onto liposome membranes to enhance antibody activity. Using trastuzumab and rituximab as examples, up to a 25-fold increase in the antibody potency in cell viability assay was observed when the antibodies were presented in the multivalent liposome formulation. Key cell survival signaling molecules, such as phosphorylated Akt and phosphorylated p65 nuclear factor-kappaB, were down-regulated on treatment with multivalent liposomal trastuzumab and liposomal rituximab, respectively. Potent in vivo antitumor activity was shown for liposomal trastuzumab. The data presented here showed the potential of liposome technology to enhance the therapeutic effect of antibodies via a mechanism that modulates cell survival through clustering of the target/antibody complex.

Predictors of distant metastasis and mortality in patients with stage II colorectal cancer

The aim of our study was to determine clinical factors that predicted distant metastasis and mortality in patients with stage II colorectal cancer (CRC). A retrospective review of all patients admitted to the Dallas Veteran's Affairs Medical Center from 1998 to 2002 with stage II CRC was performed. Factors associated with distant metastasis and mortality were assessed by univariate analysis. Independent predictors of mortality and distant metastasis were assessed by multivariate analysis. Fifty-five patients with stage II CRC were identified (96% men, age 65 +/- 1.2 years old). Univariate analysis demonstrated that patients with distant metastasis (n = 13) had a history of alcohol intake (54% vs 20%; P = 0.029), less history of angiotensin-converting enzyme inhibitor use for the management of hypertension (31% vs 67%; P = 0.029), greater incidence of a rectal location for cancer (54% vs 12%; P = 0.004), an abdominoperineal resection (APR) for surgical management of their cancers (23% vs 0%; P = 0.011), and less negative lymph nodes examined during surgical resection (9 +/- 2.2 vs 15 +/- 1.2, P = 0.022). Follow-up of at least 3 years revealed 14 mortalities. Survivors had a less preoperative serum carcinoembryonic antigen level (5.9 +/- 0.9 vs 19.1 +/- 8.6; P = 0.031), an average less tumor depth involvement (T stage: 3.0 +/- 0.03 vs 3.2 +/- 0.11; P = 0.065), more negative lymph nodes examined at the time of surgical resection (14.0 +/- 1.3 vs 10.0 +/- 1.7; P = 0.058), less incidence of rectal cancer (21% vs 43%; P = 0.060), and none had undergone an APR (0% vs. 21%; P = 0.010). Multivariate analysis revealed that alcohol intake (P = 0.014; odds ration [OR] = 5.3), patients undergoing an APR (P = 0.011; OR = 25), and less frequency of angiotensin-converting enzyme inhibitor use (P = 0.007; OR = 4.5) independently predicted distant metastasis, whereas preoperative carcinoembryonic antigen (P = 0.038; OR = 2.8) and patients undergoing an APR (P = 0.019; OR = 25) independently predicted mortality.

SAGE and antibody array analysis of melanoma-infiltrated lymph nodes: identification of Ubc9 as an important molecule in advanced-stage melanomas

Although patients diagnosed with melanoma of </= 1.00 mm thickness have a relatively good cure rate, the prognosis for patients with locally advanced and metastatic melanoma is grave. The discovery of new and effective therapies for this disease depends in large part on molecular studies that will resolve why advanced-stage melanoma is refractory to conventional chemotherapy and radiation therapy. To identify genes that have important functions in advanced-stage melanomas, in particular, in melanoma-infiltrated lymph nodes, which are not well characterized at the molecular level, we generated a LongSAGE library from a melanoma-positive lymph node, and subjected melanoma-infiltrated lymph nodes to protein expression profiling. The data document that the molecular signature of melanoma, which has spread to regional lymph nodes, is very similar to the molecular signature of primary melanomas. Equally important, we provide evidence that the ubiquitin-conjugating enzyme, Ubc9, is expressed at high levels in melanoma-positive lymph nodes, and that it plays a crucial role in preventing advanced-stage melanomas from undergoing chemotherapy-induced apoptosis.