Cancer vaccines as a therapeutic modality: the long trek

The development of cancer vaccines has been one of the several false dawns in which initial promising Phase I and Phase II clinical data have not been followed up with conclusive Phase III trials. In this review, we describe some of the successes and failures, and review the most likely reasons for Phase III failure, such as protocol changes, which are common between Phase II and III, and poorly defined patient groups. Nevertheless, significant survival results have been reported with autologous vaccines for colorectal, renal and, more recently, prostate cancer. In addition, it is becoming evident that immunotherapy is potentially synergistic with other treatment modalities, such as chemotherapy, which can reduce T-regulatory activity that inhibits the immune response to cancer vaccines. This potential for synergy should allow cancer vaccines to become part of the standard treatment regimen for many common tumours.This article is a symposium paper from the “Robert Baldwin Symposium: 50 years of Cancer Immunotherapy”, held in Nottingham, Great Britain, on 30 June 2005.     

Inhibition of Epstein-Barr-virus-transformed human chronic lymphocytic leukaemic B cells with monoclonal-antibody-Adriamycin (doxorubicin) conjugates

The anthracyclin antineoplastic agent doxorubicin (Adriamycin) was linked by four different methods of linkage to DalB02, an IgG1 murine monoclonal antibody (mAb) against surface-associated antigens on human chronic lymphocytic leukaemia (CLL) B cells. All the four conjugates fully retained the immunoreactivity of the parent DalB02. When the inhibitory effect of these conjugates was evaluated in vitro against the target D_10–1 cells (a clone derived from an Epstein-Barr-virus-transformed human CLL B cell line that binds DalB02) it was observed that one conjugate was more potent than the free drug but the others were not. When¹³¹I-labelled unmodified DalB02 and the¹³¹I-labelled DalB02-containing conjugate that was found to be potent were injected i.v. into nude mice bearing a subcutaneous D_10–1 xenograft, the percentages of the injected dose (%ID) of both¹³¹I-DalB02 and the¹³¹I-DalB02-containing conjugate that localized in the tumour were much higher than the %ID of the respective preparations that localized in normal tissues of D_10–1-xenografted mice. The systemic toxicity of the conjugate was less than that of the free drug. At an equitoxic dose level, this conjugate was a more effective inhibitor of established D_10–1 xenografts than the free drug.This study was supported by grants from the Medical Research Council of Canada (grant MT 10964) and the Cancer Research Society Inc., Montreal, Canada     

Accumulation of an organic anticancer selenium compound in a transgenic Solanaceous species shows wider applicability of the selenocysteine methyltransferase transgene from selenium hyperaccumulators

Tolerance to high selenium (Se) soils in Se-hyperaccumulating plant species is correlated with the ability to biosynthesise methylselenocysteine (MeSeCys), due to the activity of selenocysteine methyltransferase (SMT). In mammals, inclusion of MeSeCys in the diet reduces the incidence of certain cancers, so increasing the range of crop plants that can produce this compound is an attractive biotechnology target. However, in the non-Se accumulator Arabidopsis, overexpression of SMT does not result in biosynthesis of MeSeCys from selenate because the rate at which selenate is reduced to selenite by ATP sulfurylase (ATPS) is low. This limitation is less problematic in other species of the Brassicaceae that can produce MeSeCys naturally. We investigated the potential for biosynthesis of MeSeCys in other plant families using Nicotiana tabacum L., a member of the Solanaceae. When plants were watered with 200 μM selenate, overexpression of a SMT transgene caused a 2- to 4-fold increase in Se accumulation (resulting in increased numbers of leaf lesions and areas of necrosis), production of MeSeCys (up to 20% of total Se) and generation of volatile dimethyl diselenide derived directly from MeSeCys. Despite the greatly increased accumulation of total Se, this did not result in increased Se toxicity effects on growth. Overexpression of ATPS did not increase Se accumulation from selenate. Accordingly, lines overexpressing both ATPS and SMT did not show a further increase in total Se accumulation or in leaf toxicity symptoms relative to overexpression of SMT alone, but directed a greater proportion of Se into MeSeCys. This work demonstrates that the production of the cancer-preventing compound MeSeCys in plants outside the Brassicaceae is possible. We conclude that while the SMT gene from Se hyperaccumulators can probably be utilised universally to increase the metabolism of Se into MeSeCys, the effects of enhancing ATPS activity will vary depending on the species involved.     

A phase I/II trial of oxidized autologous tumor vaccines during the “watch and wait” phase of chronic lymphocytic leukemia

Based on their activity in patients with advanced stage chronic lymphocytic leukemia (CLL), a phase I/II study was designed to evaluate the feasibility, safety, and efficacy of autologous vaccines made from oxidized tumor cells in patients with earlier stage CLL, and to determine an optimal schedule of injections. Eighteen patients (at risk for disease progression and with white blood cell counts between 15 and 100×10⁶ cells/ml) were injected intramuscularly with 10 ml of oxidized autologous blood (composed mainly of CLL cells) either 12 times over 6 weeks (group 1), 12 times over 16 days (group 2), or 4 times over 6 weeks (group 3). Fourteen out of eighteen patients had Rai stage 0–II disease, while 4/18 had stage III–IV disease but did not require conventional treatment. Partial clinical responses, associated with enhanced anti-tumor T cell activity in vitro, were observed in 5/18 patients of whom three were in group 2. Stable disease was observed in six patients while disease progression appeared not to be affected in the remaining patients. Toxicity was minimal. Vaccination with oxidized autologous tumor cells appears worthy of further investigation and may be a potential alternative to a watch and wait strategy for selected CLL patients.     

Phase I pilot clinical trial of human IgM monoclonal antibody to ganglioside GM3 in patients with metastatic melanoma

Purpose: A human monoclonal antibody (L612 HuMAb) that binds to ganglioside GM3 has been developed in our laboratory. L612 HuMAb is a 100% human IgM protein. L612 HuMAb binds to cell surface of melanoma and can kill the cells in the presence of complement. The primary objective of this study was to test the toxicity and pharmacokinetics associated with administration of L612 HuMAb to melanoma patients whose tumor cells expressed GM3. Experimental design: Nine patients with measurable metastatic melanoma (American Joint Committee on Cancer stage IV) were entered in the study. Eight had failed previous treatments that included chemotherapy, radiation therapy, melanoma cell vaccine, and/or biological therapy. All patients received a 48-h continuous infusion of L612 HuMAb at a dose of 960 mg, 1,440 mg, or 1,920 mg. Five of these patients received a second infusion and one patient received a third infusion, all with the previous dose. Results: Toxicity was limited to transient and mild pruritus and skin rash. One patient complained of pain at the site of subcutaneous metastases. Serum antibody levels peaked 24 to 48 h after starting the infusion. Two patients, one receiving a single course of 960 mg (612 mg/m²) and the second receiving two courses of 1,440 mg (911 mg/m²) followed by surgical therapy, are without evidence of disease >5 years after antibody infusion. Conclusions: The human IgM monoclonal antibody, L612 HuMAb, was well tolerated. Infusion of L612 HuMAb appears to produce significant antitumor activity in melanoma patients.Dr. Ollila is currently affiliated with the University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA.Supported by grant CA 30647 from the National Institutes of Health, National Cancer Institute.     

Active and indolent chronic lymphocytic leukaemia – immune and hormonal peculiarities

 A group of 138 B cell chronic lymphocytic leukaemia (B-CLL) patients, 83 with active disease and 53 having the indolent form of the disease, were evaluated. The aim of the study was to clarify whether indolent and active B-CLL differ in their immune and hormonal characteristics. Peripheral blood lymphocyte proliferation in response to phytohaemagglutinin, concanavalin A, recombinant interleukin-2, dextran sulphate, Pisum sativatum agglutinin and wheat germ agglutinin was investigated. Serum immunoglobulin and β₂ microglobulin levels were determined. Adrenocorticotropic hormone (ACTH), cortisol, follicle-stimulating hormone luteinizing hormone, 17β-oestradiol, testosterone, triiodothyronine, thyroxine, thyroglobulin and thyrotropic hormone levels were determined by radioimmunoassay. Active and indolent CLL presented differences in immunological characteristics, as demonstrated by the more severe suppression of T lymphocyte function, reduced IgA level and considerably higher serum β2-microglobulin values in active disease. Immune disturbances were accompanied by hormonal imbalance, depending on disease status: lower ACTH, cortisol and triiodothyronine levels were established to occur in active CLL compared to indolent disease. Male patients demonstrated striking changes in sex hormones, which were more evident in active disease. The findings point to the complexity of immuno-hormonal disturbances in CLL with differences in the active and indolent state of the disease. Received: 19 June 1997 / Accepted: 14 August 1997     

Cancer prevention by carotenoids

Various natural carotenoids seem to be valuable for cancer prevention, and these carotenoids may be more suitable in combinational use, rather than in single use. In fact, we have proven that combinational use of natural carotenoids resulted in significant suppression of liver cancer. Patients of viral hepatitis with cirrhosis were administered with β-cryptoxanthin-enriched Mandarin orange juice, in addition to capsules of carotenoids mixture. Cumulative incidence of hepatocellular carcinoma development was compared with that in the group treated with carotenoids mixture capsules alone, or in the group without treatment (control group). In the data analysis at year 2.5, cumulative incidence of liver cancer in β-cryptoxanthin-enriched orange juice with carotenoids mixture capsules-treated group was lower than that in the control group (p = 0.05). Cumulative incidence of liver cancer in the group treated with carotenoids mixture capsules alone was also lower than that in the control group, but not statistically significant.     

Apoptosis induces Bcl-XS and cleaved Bcl-XL in chronic lymphocytic leukaemia

The Bcl-X gene has both pro-survival, Bcl-X_L, and pro-apoptotic, Bcl-X_S, gene products, which are produced by alternative splicing. The function of these proteins has previously been characterised in cell lines, often by transfecting expression constructs, and primary cell systems capable of dynamically regulating Bcl-X_L and Bcl-X_S have not been described. Such a system is potentially important to allow testing of agents that promote apoptosis by increasing the amount of Bcl-X_S at the expense of Bcl-X_L. In this report we characterise Bcl-X gene products in primary human leukaemic B-cells in culture conditions associated with survival and apoptosis. We found that Bcl-X_S was induced in spontaneous and drug-induced apoptosis and that apoptosis induced in cells cultured on mouse fibroblasts expressing CD40 ligand with IL-4 (CD154/IL-4), a condition mimicking the tissue microenvironment, additionally produced expression of cleavage products of Bcl-X_L. Both Bcl-X_S and Bcl-X_L were produced in a caspase dependent manner. We tested emetine, an agent previously reported to increase Bcl-X_S but found that it did not have this effect in primary human B-cells. Therefore, there are two mechanisms—cleavage of Bcl-X_L and production of Bcl-X_S—by which Bcl-X gene products could enhance apoptosis in CLL but neither appeared to have a primary role in inducing leukaemic cell death.     

Mutant p53 reactivation by small molecules makes its way to the clinic

The TP53 tumor suppressor gene is mutated in many human tumors, including common types of cancer such as colon and ovarian cancer. This illustrates the key role of p53 as trigger of cell cycle arrest or cell death upon oncogenic stress. Most TP53 mutations are missense mutations that result in single amino acid substitutions in p53 and expression of high levels of dysfunctional p53 protein. Restoration of wild type p53 function in such tumor cells will induce robust cell death and allow efficient eradication of the tumor. Therapeutic targeting of mutant p53 in tumors is a rapidly developing field at the forefront of translational cancer research. Various approaches have led to the identification of small molecules that can rescue mutant p53. These include compounds that target specific p53 mutations, including PK083 and PK5174 (Y220C mutant p53) and NSC319726 (R175H mutant p53), as well as PRIMA-1 and its analog APR-246 that affect a wider range of mutant p53 proteins. APR-246 has been tested in a Phase I/II clinical trial with promising results.     

Dendritic cell-based multi-epitope immunotherapy of hormone-refractory prostate carcinoma

Background: Dendritic cell (DC)-based immunotherapy is a promising approach to augment tumor antigen-specific T cell responses in cancer patients. However, tumor escape with down-regulation or complete loss of target antigens may limit the susceptibility of tumor cells to the immune attack. Concomitant generation of T cell responses against several immunodominant antigens may circumvent this potential drawback. In this trial, we determined the immunostimulatory capacity of autologous DC pulsed with multiple T cell epitopes derived from four different prostate-specific antigens in patients with advanced hormone-refractory prostate cancer. Patients and methods: Autologous DC of HLA-A*0201⁺ patients with hormone-refractory prostate cancer were loaded with antigenic peptides derived from prostate stem cell antigen (PSCA_14–22), prostatic acid phosphatase (PAP_299–307), prostate-specific membrane antigen (PSMA_4–12), and prostate-specific antigen (PSA_154–163). DC were intradermally applied six times at biweekly intervals followed—in the case of an enhanced immune response—by monthly booster injections. Immune monitoring during the time of ongoing vaccinations (12–59 weeks) included ex vivo ELISPOT measurements, MHC tetramer analysis and in vitro cytotoxicity assays. Results: Of the initial six patients, three qualified for long-term multi-epitope DC vaccination. This regime was tolerated well by all three patients. The vaccination elicited significant cytotoxic T cell responses against all prostate-specific antigens tested. In addition, memory T cell responses against the control peptides derived from influenza matrix protein and tetanus toxoid were efficiently boosted. Clinically, the long-term DC vaccination was associated with an increase in PSA doubling time. Conclusions: DC-based multi-epitope immunotherapy with repeated boosting in men with hormone-refractory prostate carcinoma is feasible and generates efficient cellular antitumor responses. Grant sponsors: Cancer League St. Gallen-Appenzell; Swiss Cancer League; Foundation Propter Homines Vaduz Liechtenstein; Cancer Research Institute USA; Foundation for Clinical Cancer Research of Eastern Switzerland (OSKK)     

Organoselenides from Nicotiana tabacum genetically modified to accumulate selenium

Nicotiana tabacum L. (tobacco) plants were transformed to overexpress a selenocysteine methyltransferase gene from the selenium hyperaccumulator Astragalus bisulcatus (Hook.) A. Gray (two-grooved milkvetch), and an ATP-sulfurylase gene from Brassica oleracea L. var. italica (broccoli). Solvent extraction of leaves harvested from plants treated with selenate revealed five selenium-containing compounds, of which four were identified by chemical synthesis as 2-(methylseleno)acetaldehyde, 2,2-bis(methylseleno)acetaldehyde, 4-(methylseleno)-(2E)-nonenal, and 4-(methylseleno)-(2E,6Z)-nonadienal. These four compounds have not previously been reported in nature.     

The impact of rheumatological disorders on lymphomas and myeloma: a report on risk and survival from the UK’s population-based Haematological Malignancy Research Network

BackgroundAutoimmune inflammatory disease increases the risk of diffuse large B-cell lymphoma (DLBCL) and marginal zone lymphoma (MZL), but findings for other mature B-cell malignancies are equivocal. Furthermore, it has been suggested that the increase in DLBCL is due to the activated B-cell (ABC) subtype; but data on this, and the impact of inflammatory co-morbidities on survival, are sparse and contradictory.MethodsData are from an established UK population-based cohort. Patients (n = 6834) diagnosed between 01/2009 and 08/2015 are included; DLBCL (n = 1771), myeloma (n = 1760), chronic lymphocytic leukaemia (CLL, n = 1580), MZL (n = 936), and follicular lymphoma (FL, n = 787). Information on rheumatological disorders and deaths was obtained by record-linkage to nationally compiled Hospital Episode Statistics, with age-and sex-matched individuals (n = 68,340) from the same catchment population (˜4 million people) providing the comparator.ResultsSignificantly increased risks for DLBCL (OR = 2.3, 95% CI 1.8–2.8) and MZL (OR = 2.0, 95% CI 1.5–2.7) were found for those with rheumatological disorders; the site distribution of those with/without rheumatological conditions differing for DLBCL (p = 0.007) and MZL (p = 0.002). No increases in risk were observed for the remaining mature B-cell malignancies, and no associations with survival were detected for DLBCL (age-adjusted HR = 1.2, 95% CI 0.9–1.6) or MZL (age-adjusted HR = 1.0, 95% CI 0.6–1.9). Furthermore, whilst our findings provide evidence for an association with rheumatological disease severity for DLBCL, they offer little support for the notion that the association is driven by an increase in the incidence of the ABC subtype.ConclusionOur findings support the hypothesis that the chronic activation and proliferation of specific B-cell populations which characterize autoimmune disease increase the potential for the lymphomagenic events that lead to DLBCL and MZL in both males and females; but have no impact on the development of CLL, FL or MM, or on survival.     

54 例慢性淋巴细胞白血病的临床回顾性分析*

摘要目的：本研究旨在探讨慢性淋巴细胞白血病(CLL)的实验室检查特点及特征性临床表现。方法：利用血细胞分析仪、流式细胞术、骨髓形态分析及R显带技术等对我院2002 年4 月-2012 年4 月收治的54 例慢性淋巴细胞白血病患者的相关临床资料如血细胞计数、骨髓形态、染色体及免疫表型等进行检测并对结果进行回顾性分析。结果：CLL多发于老年患者,男性多见,中位年龄65 岁（45-82 岁）。大部分患者初诊时可出现典型的临床表现,37 例（68%）患者初诊时淋巴结大,49 例（91%）初诊时白细胞≥10× 109/L,淋巴细胞绝对值≥ 5× 109/L。13 例（24%）初诊时肝脾或者脾大,17 例（31%）初诊时乏力、消瘦。34（63%）例患者可见典型的CLL免疫表型,CD5、CD19. CD23、CD20 的阳性率分别为90%、87%、72%、67%。32 例患者染色体检测结果表明：13q-2 例,17p-2 例,11q-1 例,+12 有1 例,6q-1 例,t(14,16)1 例。2 例患者发生了自身免疫性溶血性贫血（AIHA）。1例患者发生了Richter转化,肿大淋巴结活检显示部分区域为弥漫性大B细胞淋巴瘤,其高表达CD20、CD19、CD22。结论：慢性淋巴细胞白血病具有其典型的临床表现、免疫表型及遗传学改变,并且对诊断及治疗有重要意义。     

54例慢性淋巴细胞白血病的临床回顾性分析

目的：本研究旨在探讨慢性淋巴细胞白血病（CLL）的实验室检查特点及特征性临床表现。方法：利用血细胞分析仪、流式细胞术、骨髓形态分析及R显带技术等对我院2002年4月．2012年4月收治的54例慢性淋巴细胞白血病患者的相关临床资料如血细胞计数、骨髓形态、染色体及免疫表型等进行检测并对结果进行回顾性分析。结果：CLL多发于老年患者,男性多见,中位年龄65岁（45．82岁）。大部分患者初诊时可出现典型的临床表现,37例（68％）患者初诊时淋巴结大,49例（91％）初诊时白细胞≥10×109、L,淋巴细胞绝对值≥5×109／L。13例（24％）初诊时肝脾或者脾大,17例（31％）初诊时乏力、消瘦。34（63％）例患者可见典型的CLL免疫表型,CD5、CDl9．CD23、CD20的阳性率分别为90％、87％、72％、67％。32例患者染色体检测结果表明：13q-2例,17p．2例,11q-1例,＋12有1例,6q-1例,t（14,16）1例。2例患者发生了自身免疫性溶血性贫血（AIHA）。1例患者发生了Richter转化,肿大淋巴结活检显示部分区域为弥漫性大B细胞淋巴瘤,其高表达CD20、CDl9、CD22。结论：慢性淋巴细胞白血病具有其典型的临床表现、免疫表型及遗传学改变,并且对诊断及治疗有重要意义。