DNA vaccination of HSP105 leads to tumor rejection of colorectal cancer and melanoma in mice through activation of both CD4 T cells and CD8 T cells

Extracellular vesicles related gene HSPH1 exerts anti-tumor effects in prostate cancer via promoting the stress response of CD8 + T cells

BACKGROUND

T cell stress response state (TSTR), as a novel immune concept previous studies have proposed, has not yet been explored in prostate cancer (PC). As a type of cellular efflux, exosomes play important roles in the occurrence and development of PC.

METHOD

Here, we conducted a combined analysis on extracellular vesicle related genes (EVRGs) in PC using data from single-cell RNA (scRNA), spatial transcriptome (ST), and bulk RNA sequencing.

RESULT

Preliminary findings have revealed that heat shock protein family H (Hsp110) member 1 (HSPH1) possesses two identities, one being EVRGs and the other being a member of the heat shock protein family involved in TSTR, which may promote the differentiation of conventional T cells towards Th1 or Th2 cells through the pathway of IL2-MYC-IL2RA, thereby promoting the increase of CD8 + T cells in the tumor area, especially in the invasive zone, and inhibiting the invasion of PCs. We also notice the negative response of HSPH1 + CD8 + T cell related genes in immune checkpoint blockade (ICB). Western blot (WB) and droplet digital Polymerase Chain Reaction (ddPCR) demonstrated that the mRNA and protein levels of HSPH1 in EVs of PCs were significantly higher than those in adjacent tissues.

CONCLUSION

Results above indicate the potential of HSPH1 as a critical therapeutic target in PC.

Effect of Curcumin on Hepatic mRNA and lncRNA Co-Expression in Heat-Stressed Laying Hens

Heat stress is an important factor affecting poultry production; birds have a range of inflammatory reactions under high-temperature environments. Curcumin has anti-inflammatory and antioxidant effects. The purpose of this experiment was to investigate the effect of dietary curcumin supplementation on the liver transcriptome of laying hens under heat stress conditions. In the animal experiment, a total of 240 Hy-Line brown hens aged 280 days were divided randomly into four different experimental diets with four replicates, and each replicate consisted of 15 hens during a 42-D experiment. The ambient temperature was adjusted to 34 ± 2 °C for 8 h per day, transiting to a range of 22 °C to 28 °C for the remaining 16 h. In the previous study of our lab, it was found that supplemental 150 mg/kg curcumin can improve production performance, antioxidant enzyme activity, and immune function in laying hens under heat stress. To further investigate the regulatory mechanism of curcumin on heat stress-related genes, in total, six samples of three liver tissues from each of 0 mg/kg and 150 mg/kg curcumin test groups were collected for RNA-seq analysis. In the transcriptome analysis, we reported for the first time that the genes related to heat stress of mRNA, such as HSPA8, HSPH1, HSPA2, and DNAJA4, were co-expressed with lncRNA such as XLOC010450, XLOC037987, XLOC053511, XLOC061207, and XLOC100318, and all of these genes are shown to be down-regulated. These findings provide a scientific basis for the possible benefits of dietary curcumin addition in heat-stressed laying hens.

HSP105 expression in cutaneous malignant melanoma: Correlation with clinicopathological characteristics

BACKGROUND

Heat shock proteins can protect against stress-associated cellular challenges, but they can also protect some tumors from human immune system monitoring. Heat shock protein 105 (HSP105/110) is a high molecular weight protein whose expression has been reported in many cancers, but few studies on its role in cutaneous malignant melanoma have been published. In this study, we analyzed the relationship between HSP105 expression and the clinicopathological characteristics of CMM.

METHODS

This retrospective study included 91 patients with CMM. The clinicopathological characteristics of CMM patients, including age, lesion duration, location, pathological classification, Clark's level, Breslow thickness, metastasis and recurrence, were collected. Immunohistochemical staining and Western blot analysis for HSP105 were performed. Pigmented nevi (n = 20) served as a control. The staining intensity and percentage of stained cells were expressed as a histochemical score (HSCORE).

RESULTS

HSP105 was overexpressed in melanoma compared with nevi. Differences in the HSCORE between nevi (HSCORE = 1.05(0.15,1.50)) and CMM (HSCORE = 2.68(1.80,3.60)) were remarkable (P<0.001). Exposed site lesions, recurrent and metastatic lesions, nodular melanoma and lentigo maligna melanoma were closely associated with higher HSP105 expression (P = 0.011, P = 0.001 and P = 0.001, respectively). Moreover, no significant difference was observed in Clark's level, Breslow thickness, or lesion duration (P>0.05).

CONCLUSION

HSP105 is overexpressed in CMM. Higher HSP105 expression in lesions is associated with different clinicopathological variables. HSP105 may be a potential target for the diagnosis, treatment and prognostic prediction of CMM.

Tumor targeting nanoparticle E749-57-HSP110-RGD elicits potent anti-tumor immune response in a CD8-dependent manner in cervical cancer-bearing mouse model

Our previous research verified that HSP (heat shock protein) 110 could enhance the anti-tumor effect of HPV16 E7_49-57 epitope. In this study, to optimize the immunotherapy of this vaccine type, we developed and evaluated the anti-tumor immunity of a nanoparticle vaccine format assembling with E7_49-57-HSP110 fusion expression plasmid and RGD-GGG-K₁₈ polypeptide. The nanoparticle vaccine was self-assembled from positively charged RGD-GGG-K₁₈ polypeptide and negatively charged fusion expression plasmid pIRES2-3× E7-HSP110-EGFP. The particle size, stability, expression of E7_49-57-HSP110 fusion protein and the target ability of nanoparticle were determined, respectively. Specific CTL responses were determined by E7 tetramer staining and cytotoxicity assay in TC-1 tumor-bearing mice (CD4/CD8 knockout). The preventive and therapeutic experiments of nanoparticle vaccine were investigated in TC-1 tumor-bearing mice. Results showed that the RGD-GGG-K₁₈ polypeptide and pIRES2-3× E7-HSP110-EGFP plasmid self-assembled nanoparticles about 100 nanometers in diameter when the charge ratios of peptide/plasmid were 2. The nanoparticles effectively entered TC-1 cells directed by RGD target-peptide, and correctly expressed the E7-HSP110 fusion protein. The HSP110 effectively facilitated nanoparticles activating CD8⁺T cells than nanoparticles without HSP110, including the CD8⁺ T cell number and the IFN-γ level; in contrast, the CD4⁺T cells immune response remained indiscriminate among the mice groups. This nanoparticle formulation inhibited tumor growth and prolonged the survival duration in the prophylactic and therapeutic mouse models. Therefore, the RGD-based tumor-targeting nanoparticle expressing E7_49-57-HSP110 fusion protein can efficiently evoke anti-tumor activity and thus suggests it might be a favorable candidate for cervical cancer immunotherapy.

Expression of Heat Shock Protein 105 in Cutaneous Squamous Cell Carcinoma: Correlation with Clinicopathological Characteristics

Background

Heat shock proteins (HSPs), a group of heat stress proteins, are characterized by highly conserved properties. Malignant transformation is a cellular stress, and the expression of HSPs may be affected during this process. Heat shock protein 105 (HSP105) is a protective protein that has long been observed in many cancer types, but little attention has been given to cutaneous squamous cell carcinoma (CSCC). As such, the objectives of this study were to observe the expression of HSP105 on CSCC and evaluate its correlation with clinicopathological characteristics.

Methods

This retrospective study enrolled 60 patients with CSCC. The patients’ clinical data, including sex, age, tumor location, tumor type, and degree of pathological differentiation, were collected. The expression of HSP105 was measured by Western blot and immunohistochemical staining.

Results

HSP105 expression was decreased in CSCC (HSCORE=0.65 (0.30, 1.98)) compared with normal skin (HSCORE=2.20 (1.50, 2.80)) (P<0.001). These results were consistent with the Western blot analysis. HSP105 immunostaining of Bowen disease (HSCORE=1.28 (1.08, 2.40)) revealed higher expression than in verrucous carcinoma (HSCORE=0.30 (0.23, 0.85)), keratoacanthoma (HSCORE=0.53 (0.29, 0.93)) and acantholytic squamous cell carcinoma (HSCORE=0.53 (0.41, 0.68) (P<0.01)). Poorly differentiated CSCC showed significantly higher expression of HSP105.

Conclusion

Our study reveals for the first time that the expression of HSP105 is decreased in CSCC. We suggest that the molecular mechanisms underlying the differential expression of HSP deserve a more rigorous future study, the results of which might explain its role in carcinogenesis and its potential as a target for selective tumor therapy.

A promising naphthoquinone [8-hydroxy-2-(2-thienylcarbonyl)naphtho[2,3-b]thiophene-4,9-dione] exerts anti-colorectal cancer activity through ferroptosis and inhibition of MAPK signaling pathway based on RNA sequencing

Naphthoquinones are naturally occurring metabolites with recognized anti-cancer potential but limited clinical application. This study investigated the molecular mechanism of 8-hydroxy-2-(2-thenoyl)naphtho[2,3-b]thiophene-4,9-dione (1), a new candidate for colorectal cancer (CRC) treatment, using different experimental settings: MTT, clonogenic, wound healing, and cell cycle assays; as well as RNA sequencing. Naphthoquinone 1 selectively reduced the viability and migration of HT-29 cells by G2/M arrest and changes in their transcriptome signature with significant effect on cellular survival, proliferation, angiogenesis, response to interferon, oxidative stress, and immune response. Impact analysis identified ferroptosis and MAPK pathways as significantly affected. In summary, our results suggest that 1 induces the selective death of CRC cells by inducing oxidative stress, ferroptosis, and MAPK inhibition.

Molecular Pathway Analysis Indicates a Distinct Metabolic Phenotype in Women With Right-Sided Colon Cancer

Colon cancer is the third most commonly diagnosed cancer in the United States. Recent reports have shown that the location of the primary tumor is of clinical importance. Patients with right-sided colon cancers (RCCs) (tumors arising between the cecum and proximal transverse colon) have poorer clinical outcomes than those with left-sided colon cancers (LCCs) (tumors arising between the distal transverse colon and sigmoid colon, excluding the rectum). Interestingly, women have a lower incidence of colon cancer than men, but have a higher propensity for RCC. The reason for this difference is not known; however, identification of sex-specific differences in gene expression by tumor anatomical location in the colon could provide further insight. Moreover, it could reveal important predictive markers for response to various treatments. This study provides a comprehensive bioinformatic analysis of various genes and molecular pathways that correlated with sex and anatomical location of colon cancers using four publicly available annotated data sets housed in the National Center for Biotechnology Information's Gene Expression Omnibus. We identified differentially expressed genes in tumor tissues from women with RCC, which showed attenuated energy and nutrient metabolism when compared with women with LCC. Specifically, we showed the downregulation of 5′ AMP-activated protein kinase alpha subunit (AMPKα) and anti-tumor immune responses in women with RCC. This difference was not seen when comparing tumor tissues from men with RCC to men with LCC. Therefore, women with RCC may have a specific metabolic and immune phenotype which accounts for differences in prognosis and treatment response.

Heat shock protein 105 peptide vaccine could induce antitumor immune reactions in a phase I clinical trial

Heat shock protein 105 (HSP105) is overexpressed in many cancers, including colorectal cancer (CRC) and esophageal cancer (EC). We carried out a phase I clinical trial of HLA-A24- and HLA-A2-restricted HSP105 peptide vaccines in patients with CRC or EC. In this additional study of the trial, we examined the immunological efficacy of the novel vaccine. Thirty patients with advanced CRC or EC underwent HSP105 peptide vaccination. Immunological responses were evaluated by ex vivo and in vitro γ-interferon enzyme-linked immunospot assays and their correlation with patients' prognosis was analyzed. The HSP105 peptide vaccines induced peptide-specific CTLs in 15 of 30 patients. Among HLA-A24 patients (n = 15), 7 showed induction of CTLs only ex vivo, whereas among HLA-A2 patients (n = 15), 4 showed the induction ex vivo and 6 in vitro. Heat shock protein 105-specific CTL induction correlated with suppression of cancer progression and was revealed as a potential predictive biomarker for progression-free survival (P = .008; hazard ratio = 3.03; 95% confidence interval, 1.34-6.85) and overall survival (P = .025; hazard ratio = 2.72; 95% confidence interval, 1.13-6.52). Production of cytokines by HSP105 peptide-specific CTLs was observed at the injection sites (skin) and tumor tissues, suggesting that HSP105-specific CTLs not only accumulated at vaccination sites but also infiltrated tumors. Furthermore, we established 2 HSP105 peptide-specific CTL clones, which showed HSP105-specific cytokine secretion and cytotoxicity. Our results suggest that the HSP105 peptide vaccine could induce immunological effects in cancer patients and improve their prognosis.

Heat shock-induced mitotic arrest requires heat shock protein 105 for the activation of spindle assembly checkpoint

Heat shock causes proteotoxic stress that induces various cellular responses, including delayed mitotic progression and the generation of an aberrant number of chromosomes. In this study, heat shock delayed the onset of anaphase by increasing the number of misoriented cells, accompanied by the kinetochore localization of budding uninhibited by benzimidazole-related (BubR)1 in a monopolar spindle (Mps)1-dependent manner. The mitotic delay was canceled by knockdown of mitotic arrest defect (Mad)2. Knockdown of heat shock protein (Hsp)105 partially abrogated the mitotic delay with the loss of the kinetochore localization of BubR1 under heat shock conditions and accelerated mitotic progression under nonstressed conditions. Consistent with this result, Hsp105 knockdown increased the number of anaphase cells with lagging chromosomes, through mitotic slippage, and decreased taxol sensitivity more than Mad2 knockdown. Hsp105 was coprecipitated with cell division cycle (Cdc)20 in an Mps1-dependent manner; however, its knockdown did not affect coprecipitation of Mad2 and BubR1 with Cdc20. We propose that heat shock delays the onset of anaphase via the activation of the spindle assembly checkpoint (SAC). Hsp105 prevents abnormal cell division by contributing to SAC activation under heat shock and nonstressed conditions by interacting with Cdc20 but not affecting formation of the mitotic checkpoint complex.-Kakihana, A., Oto, Y., Saito, Y., Nakayama, Y. Heat shock-induced mitotic arrest requires heat shock protein 105 for the activation of spindle assembly checkpoint.

Immunotherapy regimens for metastatic colorectal carcinomas

Metastatic colorectal cancer (mCRC) is a leading cause of cancer-related mortality with a 5-year overall survival rate of 13%. Despite recent advances in cancer immunotherapy, only the minority of CRC patients (<15%) with microsatellite instability can potentially benefit from immune checkpoint inhibitors, the only immunotherapy currently approved for mCRC. In that context, there is an unmet need to improve survival in mCRC. Our ever-increasing understanding of the immune system and its interactions with cancer has allowed development of multiple strategies to potentially improve outcomes in the majority of mCRC patients. Various approaches to manipulate patient immunity to recognize and kill colorectal cancer cells are being explored simultaneously, with combination therapies likely being the most effective. Ideally, therapies would target tumor-restricted antigens selectively found in tumors, but shielded from immune attack in normal tissues, to mount an effective cytotoxic T-cell response, while also overcoming cellular and molecular inhibitory pathways, self-tolerance, and T-cell exhaustion. Here, we provide a brief overview of the most promising immunotherapy candidates in mCRC and their strategies to produce a lasting immune response and clinical benefit in patients with mCRC.

Unfolding the Role of Large Heat Shock Proteins: New Insights and Therapeutic Implications

Heat shock proteins (HSPs) of eukaryotes are evolutionarily conserved molecules present in all the major intracellular organelles. They mainly function as molecular chaperones and participate in maintenance of protein homeostasis in physiological state and under stressful conditions. Despite their relative abundance, the large HSPs, i.e., Hsp110 and glucose-regulated protein 170 (Grp170), have received less attention compared to other conventional HSPs. These proteins are distantly related to the Hsp70 and belong to Hsp70 superfamily. Increased sizes of Hsp110 and Grp170, due to the presence of a loop structure, result in their exceptional capability in binding to polypeptide substrates or non-protein ligands, such as pathogen-associated molecules. These interactions that occur in the extracellular environment during tissue injury or microbial infection may lead to amplification of an immune response engaging both innate and adaptive immune components. Here, we review the current advances in understanding these large HSPs as molecular chaperones in proteostasis control and immune modulation as well as their therapeutic implications in treatment of cancer and neurodegeneration. Given their unique immunoregulatory activities, we also discuss the emerging evidence of their potential involvement in inflammatory and immune-related diseases.

Targeting cancer testis antigens for biomarkers and immunotherapy in colorectal cancer: Current status and challenges

Colorectal cancer ranks third among the estimated cancer cases and cancer related mortalities in United States in 2014. Early detection and efficient therapy remains a significant clinical challenge for this disease. Therefore, there is a need to identify novel tumor associated molecules to target for biomarker development and immunotherapy. In this regard, cancer testis antigens have emerged as a potential targets for developing novel clinical biomarkers and immunotherapy for various malignancies. These germ cell specific proteins exhibit aberrant expression in cancer cells and contribute in tumorigenesis. Owing to their unique expression profile and immunogenicity in cancer patients, cancer testis antigens are clinically referred as the most promising tumor associated antigens. Several cancer testis antigens have been studied in colorectal cancer but none of them could be used in clinical practice. This review is an attempt to address the promising cancer testis antigens in colorectal cancer and their possible clinical implications as biomarkers and immunotherapeutic targets with particular focus on challenges and future interventions.

Autonomous inhibition of apoptosis correlates with responsiveness of colon carcinoma cell lines to ciglitazone

Colorectal cancer is a leading cause of mortality worldwide. Resistance to therapy is common and often results in patients succumbing to the disease. The mechanisms of resistance are poorly understood. Cells basically have two possibilities to survive a treatment with potentially apoptosis-inducing substances. They can make use of their existing proteins to counteract the induced reactions or quickly upregulate protective factors to evade the apoptotic signal. To identify protein patterns involved in resistance to apoptosis, we studied two colorectal adenocarcinoma cell lines with different growth responses to low-molar concentrations of the thiazolidinedione Ciglitazone: HT29 cells underwent apoptosis, whereas SW480 cells increased cell number. Fluorescence detection and autoradiography scans of 2D-PAGE gels were performed in both cell lines to assess protein synthesis and turnover, respectively. To verify the data we performed shotgun analysis using the same treatment procedure as in 2D-experiments. Biological functions of the identified proteins were mainly associated with apoptosis regulation, chaperoning, intrinsic inflammation, and DNA repair. The present study suggests that different growth response of two colorectal carcinoma cell lines after treatment with Ciglitazone results from cell-specific protein synthesis and differences in protein regulation.

Identification of HLA-A2 or HLA-A24-restricted CTL epitopes for potential HSP105-targeted immunotherapy in colorectal cancer

We previously reported that heat shock protein 105 (HSP105) is overexpressed in a variety of human cancers, including colorectal, pancreatic and esophageal cancer and has proven to be a novel biomarker for the immunohistochemical detection of these cancers. In the present study, we used HLA-transgenic mice (Tgm) and the peripheral blood mononuclear cells (PBMCs) of colorectal cancer patients to identify HLA-A2 and HLA-A24-restricted HSP105 epitopes, as a means of expanding the application of HSP105-based immunotherapy to HLA-A2- or HLA-A24-positive cancer patients. In addition, we investigated by ex vivo IFN-γ ELISPOT assay whether the HSP105-derived peptide of cytotoxic T cells (CTLs) exists in PBMCs of pre-surgical colorectal cancer patients. We found that four peptides, HSP105 A2-7 (RLMNDMTAV), HSP105 A2-12 (KLMSSNSTDL), HSP105 A24-1 (NYGIYKQDL) and HSP105 A24-7 (EYVYEFRDKL), are potential HLA-A2 or HLA-A24-restricted CTL HSP105-derived epitopes. HSP105-specific IFN-γ-secreting T cells were detected in 14 of 21 pre-surgical patients with colorectal cancer in response to stimulation with these four peptides. Our study raises the possibility that these HSP105 peptides are applicable to cancer immunotherapy in patients with HSP105-expressing cancer, particularly colorectal cancer.

Potential biomarkers for malignant melanoma

Melanoma is one of the most aggressive cancers and its high metastatic potential has a large impact on the number of melanoma deaths. The pathological diagnosis is still the gold standard for melanoma and immunohistochemistry plays an important role in discriminating between melanomas. Recently, emerging molecular knowledge may lead to further identification of clinically relevant biomarkers, such as S100B, MIA, TA-90IC, 5-S-CD, SPARC, CSPG4, HSP105, IMP3, KIF2A, miR-221, YKL-40, some cancer stem cells (CD133, Nestin, CD166, CD20, CD271) and some monoclonal antibodies (KBA62, PNL2), for malignant melanoma detection, risk stratification and prediction/prognosis. However, all of the current main markers have some shortcomings. For example, all markers have limitations in sensitivity and specificity, even the first-line marker, S100 protein. So, sometimes, many of the classification criteria that have been proposed show considerable overlap, making it difficult to categorize cases reproducibly, based on histopathological criteria alone. Besides that, the increased expression of some proteins in melanomas suggests that there are abnormal proteins synthesized due to the genetic pathway. Therefore, we expect that there will be more instrumental breakthroughs in the abnormal gene field, especially with respect to gene mutation. Ultimately, novel melanoma biomarkers could be found and gradually become targeted treatment strategies for a poor prognosis in advanced melanoma in the near future.

Identification of tumor antigens that elicit a humoral immune response in the sera of Chinese esophageal squamous cell carcinoma patients by modified serological proteome analysis

Our aim was to identify novel tumor-associated antigens from the esophageal squamous cell carcinoma (ESCC) cell line EC0156, and related autoantibodies in sera from patients with ESCC. We used modified serological proteome analysis, involving one- and two-dimensional electrophoresis, Western blot, and MALDI-TOF/TOF-MS to identify 6 ESCC-associated antigens. From these, 105 kDa heat shock protein (HSP105) and triosephosphate isomerase (TIM) were further evaluated and we determined they could induce autoantibody responses in ESCC sera and are highly expressed in ESCC tissues. Anti-HSP105 and anti-TIM autoantibodies were found in 39.1% (18/46) and 34.8% (16/46) of patients with ESCC, respectively, but only in two controls. A receiver operating characteristic curve constructed with HSP105 and TIM gave a sensitivity of 54.3% and 95% (38/40) specificity in discriminating ESCC from matched controls. Interestingly, we found that autoantibodies against TIM in ESCC serum mainly reacted with glycosylated but not deglycosylated TIM. The preliminary results suggest the potential utility of screening autoantibodies in sera for use as biomarkers for cancer diagnosis.

High molecular weight stress proteins: Identification, cloning and utilisation in cancer immunotherapy

Although the large stress/heat shock proteins (HSPs), i.e. Hsp110 and Grp170, were identified over 30 years ago, these abundant and highly conserved molecules have received much less attention compared to other conventional HSPs. Large stress proteins act as molecular chaperones with exceptional protein-holding capability and prevent the aggregation of proteins induced by thermal stress. The chaperoning properties of Hsp110 and Grp170 are integral to the ability of these molecules to modulate immune functions and are essential for developing large chaperone complex vaccines for cancer immunotherapy. The potent anti-tumour activity of the Hsp110/Grp170-tumour protein antigen complexes demonstrated in preclinical studies has led to a phase I clinical trial through the National Cancer Institute's rapid access to intervention development (RAID) programme that is presently underway. Here we review aspects of the structure and function of these large stress proteins, their roles as molecular chaperones in the biology of cell stress, and prospects for their use in immune regulation and cancer immunotherapy. Lastly, we will discuss the recently revealed immunosuppressive activity of scavenger receptor A that binds to Hsp110 and Grp170, as well as the feasibility of targeting this receptor to promote T-cell activation and anti-tumour immunity induced by large HSP vaccines and other immunotherapies.

Serological identification of HSP105 as a novel non-Hodgkin lymphoma therapeutic target

We reported that the clinical efficacy of dendritic cell–based vaccination is strongly associated with immunologic responses in relapsed B-cell non-Hodgkin lymphoma (B-NHL) patients. We have now investigated whether postvaccination antibodies from responders recognize novel shared NHL-restricted antigens. Immunohistochemistry and flow cytometry showed that they cross-react with allogeneic B-NHLs at significantly higher levels than their matched prevaccination samples or nonresponders' antibodies. Western blot analysis of DOHH-2 lymphoma proteome revealed a sharp band migrating at approximately 100 to 110 kDa only with postvaccine repertoires from responders. Mass spectrometry identified heat shock protein-105 (HSP105) in that molecular weight interval. Flow cytometry and immunohistochemistry disclosed HSP105 on the cell membrane and in the cytoplasm of B-NHL cell lines and 97 diagnostic specimens. A direct correlation between HSP105 expression and lymphoma aggressiveness was also apparent. Treatment of aggressive human B-NHL cell lines with an anti-HSP105 antibody had no direct effects on cell cycle or apoptosis but significantly reduced the tumor burden in xenotransplanted immunodeficient mice. In vivo antilymphoma activity of HSP105 engagement was associated with a significant local increase of Granzyme B+ killer cells that very likely contributed to the tumor-restricted necrosis. Our study adds HSP105 to the list of nononcogenes that can be exploited as antilymphoma targets.

Antitumor and antimetastatic actions of anthrone-C-glucoside, cassialoin isolated from Cassia garrettiana heartwood in colon 26-bearing mice

We examined the antitumor and antimetastatic actions of 10-hydroxy-anthrone-C-glucoside cassialoin isolated from Cassia garrettiana heartwood in colon 26-bearing mice. Cassialoin (5 and 10 mg/kg) inhibited tumor growth and metastasis to the abdomen and the expression of CD31 (angiogenesis marker) in the tumors, and it increased the numbers of the gamma-interferon (IFN-gamma)-positive, CD8(+) T and natural killer cells in the small intestine or spleen of colon 26-bearing mice. Furthermore, cassialoin inhibited tumor-induced angiogenesis in colon 26-packed chamber-bearing mice. We examined the metabolic activities in the blood, stomach and small intestine after p.o. administration of cassialoin to mice. These results suggest that cassialoin might be converted to chrysophanol through chrysophanol-9-anthrone and metabolized to aloe-emodin from chrysophanol. Chrysophanol-9-anthrone inhibited vascular endothelial growth factor (VEGF) and matrix metallopeptidase-9 expression in colon 26 cells at 5 and 10 microM, and it inhibited VEGF-induced angiogenesis and migration in human umbilical vein endothelial cells (HUVEC) at 0.5-10 microM. Furthermore, chrysophanol-9-anthrone inhibited VEGF receptor (VEGFR)-2 expression and VEGF-induced VEGFR-2 phosphorylation. Aloe-emodin also inhibited the VEGF-induced angiogenesis by HUVEC at 1-100 microM. Cassialoin, chrysophanol-9-anthrone and aloe-emodin enhanced concanavalin A-induced IFN-gamma production in splenocytes of colon 26-bearing mice at a low concentration of 0.1 microM. From these results, it is suggested that the antitumor and antimetastatic actions of p.o. administered cassialoin may be partly due to cassialoin and its metabolites such as chrysophanol-9-anthrone and aloe-emodin through their anti-angiogenic activities and/or the modulation of the immune systems in the spleen and small intestine in tumor-bearing mice.

Tumor vaccine therapy against recrudescent tumor using dendritic cells simultaneously transfected with tumor RNA and granulocyte macrophage colony-stimulating factor RNA

Recently, dendritic cells (DC) transfected with tumor RNA have been used as a cancer vaccine. The efficacy of a cancer vaccine using DC transfected tumor RNA was examined. Of particular interest was whether a vaccine using DC transfected with recrudescent tumor RNA is effective for the treatment of a regrowing tumor after prior immunotherapy. In addition, the usefulness of co-transfection of granulocyte macrophage colony-stimulating factor (GM-CSF) mRNA to augment the DC vaccine was examined. CT26 tumor-bearing mice were immunized by s.c. injection with DC transfected with CT26 mRNA (DC-CT26). The cytotoxic activity against CT26 in mice immunized with DC-CT26 was significantly higher than that in the control group (P < 0.001) and was augmented by GM-CSF mRNA co-transfection (P < 0.05), resulting in remarkable therapeutic efficacy in CT26 s.c. tumor models. Cytotoxic T lymphocytes induced by the vaccination using DC transfected with mRNA from the recrudescent tumor showed a potent cytotoxicity against the recrudescent CT26 tumor cells, which was significantly higher than the cytotoxicity induced by the vaccination using DC-CT26 (P < 0.05). In addition, in a recrudescent tumor model, this vaccination suppressed the regrowing s.c. tumors, and was augmented by GM-CSF mRNA co-transfection (P < 0.05). These results suggested that vaccination therapy using DC simultaneously transfected with whole tumor RNA and GM-CSF mRNA could generate therapeutic immune responses even against recrudescent tumor after prior vaccination.

Regression of intestinal adenomas by vaccination with heat shock protein 105-pulsed bone marrow-derived dendritic cells in Apc(Min/+) mice

Heat shock protein (HSP) 105 is overexpressed in various cancers, but is expressed at low levels in many normal tissues, except for the testis. A vaccination with HSP105-pulsed bone marrow-derived dendritic cells (BM-DC) induced antitumor immunity without causing an autoimmune reaction in a mouse model. Because Apc(Min/+) mice develop multiple adenomas throughout the intestinal tract by 4 months of age, the mice provide a clinically relevant model of human intestinal tumor. In the present study, we investigated the efficacy of the HSP105-pulsed BM-DC vaccine on tumor regression in the Apc(Min/+) mouse. Western blot and immunohistochemical analyses revealed that the tumors of the Apc(Min/+) mice endogenously overexpressed HSP105. Immunization of the Apc(Min/+) mice with a HSP105-pulsed BM-DC vaccine at 6, 8, and 10 weeks of age significantly reduced the number of small-intestinal polyps accompanied by infiltration of both CD4(+) and CD8(+) T cells in the tumors. Cell depletion experiments proved that both CD4(+) and CD8(+) T cells play a critical role in the activation of antitumor immunity induced by these vaccinations. These findings indicate that the HSP105-pulsed BM-DC vaccine can provide potent immunotherapy for tumors that appear spontaneously as a result of the inactivation of a tumor suppressor gene, such as in the Apc(Min/+) mouse model.

Multiple gene expression classifiers from different array platforms predict poor prognosis of colorectal cancer

PURPOSE

This study aimed to develop gene classifiers to predict colorectal cancer recurrence. We investigated whether gene classifiers derived from two tumor series using different array platforms could be independently validated by application to the alternate series of patients.

EXPERIMENTAL DESIGN

Colorectal tumors from New Zealand (n = 149) and Germany (n = 55) patients had a minimum follow-up of 5 years. RNA was profiled using oligonucleotide printed microarrays (New Zealand samples) and Affymetrix arrays (German samples). Classifiers based on clinical data, gene expression data, and a combination of the two were produced and used to predict recurrence. The use of gene expression information was found to improve the predictive ability in both data sets. The New Zealand and German gene classifiers were cross-validated on the German and New Zealand data sets, respectively, to validate their predictive power. Survival analyses were done to evaluate the ability of the classifiers to predict patient survival.

RESULTS

The prediction rates for the New Zealand and German gene-based classifiers were 77% and 84%, respectively. Despite significant differences in study design and technologies used, both classifiers retained prognostic power when applied to the alternate series of patients. Survival analyses showed that both classifiers gave a better stratification of patients than the traditional clinical staging. One classifier contained genes associated with cancer progression, whereas the other had a large immune response gene cluster concordant with the role of a host immune response in modulating colorectal cancer outcome.

CONCLUSIONS

The successful reciprocal validation of gene-based classifiers on different patient cohorts and technology platforms supports the power of microarray technology for individualized outcome prediction of colorectal cancer patients. Furthermore, many of the genes identified have known biological functions congruent with the predicted outcomes.

Heat shock protein 105 is overexpressed in squamous cell carcinoma and extramammary Paget disease but not in basal cell carcinoma

BACKGROUND

Heat shock protein (HSP) 105 is a 105-kDa protein, recently discovered by serological analysis of recombinant cDNA expression libraries prepared from tumour cells (SEREX), and is still undergoing intensive research. SEREX can define strongly immunogenic tumour antigens that elicit both cellular and humoral immunity. Previous studies have shown that HSP105 is a cancer testis antigen and is overexpressed in various internal malignancies. The expression of HSP105 has not been studied in skin cancers.

OBJECTIVES

To assess the expression of HSP105 in skin cancers including extramammary Paget disease (EMPD), cutaneous squamous cell carcinoma (SCC) and basal cell carcinoma (BCC).

METHODS

Samples of EMPD (n = 25), SCC (n = 23, of which three were metastatic lesions) and BCC (n = 23) were collected from patients treated in our department between January 2002 and December 2004. Western blot and immunohistochemical staining methods were used to investigate the expression of HSP105.

RESULTS

Results of Western blot analysis showed overexpression of HSP105 in EMPD and SCC, and minimal expression in BCC. Immunohistochemistry results showed that 56% of EMPD, 60% of primary and 100% of metastatic SCC highly expressed HSP105 while only 13% of BCC lesions showed increased staining.

CONCLUSIONS

EMPD and SCC overexpress HSP105 while BCC does not. Tumours overexpressing HSP105 present ideal candidates for vaccination by HSP105-derived peptides or DNA.

Immunization with heat shock protein 105-pulsed dendritic cells leads to tumor rejection in mice

Recently, we reported that heat shock protein 105 (HSP105) DNA vaccination induced anti-tumor immunity. In this study, we set up a preclinical study to investigate the usefulness of dendritic cells (DCs) pulsed with mouse HSP105 as a whole protein for cancer immunotherapy in vivo. The recombinant HSP105 did not induce DC maturation, and the mice vaccinated with HSP105-pulsed BM-DCs were markedly prevented from the growth of subcutaneous tumors, accompanied with a massive infiltration of both CD4+ T cells and CD8+ T cells into the tumors. In depletion experiments, we proved that both CD4+ T cells and CD8+ T cells play a crucial role in anti-tumor immunity. Both CD4+ T cells and CD8+ T cells specific to HSP105 were induced by stimulation with HSP105-pulsed DCs. As a result, vaccination of mice with BM-DCs pulsed with HSP105 itself could elicit a stronger tumor rejection in comparison to DNA vaccination.