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Akseli Hemminki

Publications and source records attributed to Akseli Hemminki.

At least 19 recordsLinked to original sources
PubMed2007

Chlorpromazine and apigenin reduce adenovirus replication and decrease replication associated toxicity.

BACKGROUND: Adenoviruses can cause severe toxicity in immunocompromised individuals. Although clinical trials have confirmed the potency and safety of selectively oncolytic adenoviruses for treatment of advanced cancers, increasingly effective agents could result in more toxicity and therefore it would be useful if replication could be abrogated if necessary. METHODS: We analyzed the effect of chlorpromazine, an inhibitor of clathrin-dependent endocytosis and apigenin, a cell cycle regulator, on adenovirus replication and toxicity. First, we evaluated the in vitro replication of a tumor targeted Rb-p16 pathway selective oncolytic adenovirus (Ad5/3-Delta24) and a wild-type adenovirus in normal cells, fresh liver samples and in ovarian cancer cell lines. Further, we analyzed the in vitro cell killing efficacy of adenoviruses in the presence and absence of the substances. Moreover, the effect on in vivo efficacy, replication and liver toxicity of the adenoviruses was evaluated. RESULTS: We demonstrate in vitro and in vivo reduction of adenovirus replication and associated toxicity with chlorpromazine and apigenin. Effective doses were well within what would be predicted safe in humans. CONCLUSIONS: Chlorpromazine and apigenin might reduce the replication of adenovirus, which could provide a safety switch in case replication-associated side effects are encountered in patients. In addition, these substances could be useful for the treatment of systemic adenoviral infections in immunosuppressed patients.

Adenocarcinoma↗
PubMed2006

Noninvasive imaging for evaluation of the systemic delivery of capsid-modified adenoviruses in an orthotopic model of advanced lung cancer.

BACKGROUND: Variable expression of the coxsackie and adenovirus receptor (CAR) has limited gene transfer efficacy to many types of tumors. Consequently, tropism-modified adenoviruses have been developed for enhanced infectivity. To the authors' knowledge, targeting approaches for nonsmall cell lung cancer (NSCLC) have not been comprehensively evaluated. The current hypothesis was that modified adenoviruses could be used for increasing gene transfer to and killing of NSCLC cells in vitro and in vivo. METHODS: Ten NSCLC cell lines were analyzed to represent the different NSCLC histologies. Because clinical tumors may differ from established cell lines, 6 clinical specimens fresh from patients were analyzed. For in vivo studies, a novel orthotopic murine model of advanced lung cancer was developed. Because tumor response is difficult to quantitate in orthotopic models, noninvasive imaging of green fluorescent protein (GFP) was utilized as a surrogate for tumor size measurements. RESULTS: Adenoviruses whose capsids were modified with RGD-4C, the serotype 3 knob, or polylysine displayed increased gene transfer to NSCLC cell lines and clinical samples in comparison to serotype 5 viruses. Conditionally replicating oncolytic adenoviruses (CRAds) with the same modifications showed enhanced therapeutic efficiency in vitro and in vivo. The median survival of mice treated with Ad5.pK7-Delta24 or Ad5-Delta24RGD increased 37% (P<.01). GFP imaging allowed noninvasive individualized detection of response and recurrence. CONCLUSIONS: Targeting of adenovirus to heterologous receptors can improve killing of NSCLC cells. Utilization of clinical samples and an orthotopic model of advanced lung cancer may provide clinically relevant translational data.

Adenoviridae↗
PubMed2006

Capsid modifications overcome low heterogeneous expression of heparan sulfate proteoglycan that limits AAV2-mediated gene transfer and therapeutic efficacy in human ovarian carcinoma.

OBJECTIVES: Capsid-modified AAV vectors can mediate enhanced gene transfer to neoplasms characterized by low AAV receptor expression. Here we sought to determine the therapeutic potential of a capsid-modified AAV vector for gene therapy of ovarian carcinoma (OvCa). METHODS: We tested a panel of OvCa cell lines for AAV2-mediated gene transduction and for sensitivity to ganciclovir (GCV) following AAVHSVtk administration. Levels of AAV internalization and attachment receptor were assessed by flow cytometry and immunohistochemistry. The role of receptors in AAV-mediated gene transfer was assessed by competition assays. Finally, we examined the ability of a modified vector with an integrin-binding RGD motif inserted into the AAV capsid to improve gene delivery to OvCa and enhance AAVHSVtk/GCV-mediated killing by cytotoxicity assay. RESULTS: All OvCa cell lines were poorly transduced with AAV2 vectors and showed variably sensitive to AAVHSVtk/GCV. While OvCa cell lines expressed AAV2 internalization receptors (alphav integrins), expression of the AAV2 attachment receptor, HSPG, was variable and not detected on many lines. Analysis of archived clinical specimens showed no detectable HSPG expression on approximately 45% of primary human tumors. Gene transfer to OvCa was increased several fold using the RGD-modified vector. Gene transfer was independent of HSPG and specific to the targeted receptor. Importantly, the RGD-modified capsid markedly increased the ability of the AAVHSVtk to kill OvCa cells in the presence of GCV. CONCLUSIONS: The development of AAV vectors targeted to cell surface receptors other than HSPG will be critical to the advancement of AAV-mediated gene therapy for treating OvCa.

Adenoviridae↗
PubMed2006

Infectivity-enhanced adenoviruses deliver efficacy in clinical samples and orthotopic models of disseminated gastric cancer.

PURPOSE: Metastatic gastric cancer remains a common and devastating disease without curative treatment. Recent proof-of-concept clinical trials have validated gene therapy with adenoviruses as an effective and safe modality for the treatment of cancer. However, expression of the primary coxsackie-adenovirus receptor is variable in advanced cancers, and therefore, the use of heterologous receptors could be advantageous. EXPERIMENTAL DESIGN: Here, we used capsid-modified adenoviruses for increasing the transduction and subsequent antitumor efficacy. 5/3 chimeric viruses have a serotype 3 knob which allows binding to a receptor distinct from coxsackie-adenovirus receptor. The fiber of Ad5lucRGD is modified with an integrin-targeted motif. Polylysine motifs, pK7 and pK21, bind to heparan sulfates. Oncolytic adenoviruses replicate in and kill tumor cells selectively. Gastric cancer cell lines and fresh clinical samples from patients were infected with transductionally targeted viruses. Capsid-modified oncolytic adenoviruses were used in cell killing experiments. To test viral transduction and therapeutic efficacy in vivo, we developed orthotopic mouse models featuring i.p. disseminated human gastric cancer, which allowed the evaluation of biodistribution and antitumor efficacy in a system similar to humans. RESULTS: Capsid modifications benefited gene transfer efficiency and cell killing in gastric cancer cell lines and clinical samples in vitro and in vivo. Modified oncolytic adenoviruses significantly increased the survival of mice with orthotopic gastric cancer. CONCLUSIONS: These preclinical data set the stage for the clinical evaluation of safety and efficacy in patients with disease refractory to current modalities.

Adenoviridae↗
PubMed2006

Gene transfer approaches for gynecological diseases.

Gene transfer presents a potentially useful approach for the treatment of diseases refractory to conventional therapies. Various preclinical and clinical strategies have been explored for treatment of gynecological diseases. Given the direst need for novel treatments, much of the work has been performed with gynecological cancers and ovarian cancer in particular. Although the safety of many approaches has been demonstrated in early phase clinical trials, efficacy has been mostly limited so far. Major challenges include improving gene transfer vectors for enhanced and selective delivery and achieving effective penetration and spread within advanced and complex tumor masses. This review will focus on current and developmental gene transfer applications for gynecological diseases.

Adenoviridae↗
PubMed2006

Triple-targeted oncolytic adenoviruses featuring the cox2 promoter, E1A transcomplementation, and serotype chimerism for enhanced selectivity for ovarian cancer cells.

Conditionally replicating adenoviruses (CRAd's) feature selective replication in and killing of tumor cells. Initial clinical studies with relatively attenuated early generation agents have resulted in promising safety and efficacy data. Nevertheless, increased specificity may be advantageous for an emerging generation of infectivity-enhanced CRAd's. Further, increased specificity could translate into a larger tolerated dose. An approach for increasing specificity is dual control of E1A expression. We constructed six CRAd's featuring two variants of the cyclo-oxygenase 2 (cox2) promoter, combined with three versions of E1A. Transcriptional targeting was supplemented with transductional targeting utilizing the serotype 3 knob. In vivo and in vitro results suggest that cox2 can be utilized for enhancing the specificity of E1A deletion mutants and that combination with the Delta24 mutation increases specificity without reducing potency. Combination with Delta2-Delta24 was specific but somewhat attenuated. The promoter variants behaved similarly, although the longer 1,554-bp version displayed a trend for improved specificity. Transcriptional modifications were compatible with transductional targeting and resulted in up to 100,000-fold increase in the therapeutic window for Ad5/3cox2Ld24 vs wild-type adenovirus. Thus, the proposed triple-targeting strategy may be useful for increasing the safety and efficacy of adenoviral gene therapy for ovarian cancer.

Adenoviridae↗
PubMed2006

Adjuvant docetaxel or vinorelbine with or without trastuzumab for breast cancer.

BACKGROUND: We compared docetaxel with vinorelbine for the adjuvant treatment of early breast cancer. Women with tumors that overexpressed HER2/neu were also assigned to receive concomitant treatment with trastuzumab or no such treatment. METHODS: We randomly assigned 1010 women with axillary-node-positive or high-risk node-negative cancer to receive three cycles of docetaxel or vinorelbine, followed by (in both groups) three cycles of fluorouracil, epirubicin, and cyclophosphamide. The 232 women whose tumors had an amplified HER2/neu gene were further assigned to receive or not to receive nine weekly trastuzumab infusions. The primary end point was recurrence-free survival. RESULTS: Recurrence-free survival at three years was better with docetaxel than with vinorelbine (91 percent vs. 86 percent; hazard ratio for recurrence or death, 0.58; 95 percent confidence interval, 0.40 to 0.85; P=0.005), but overall survival did not differ between the groups (P=0.15). Within the subgroup of patients who had HER2/neu-positive cancer, those who received trastuzumab had better three-year recurrence-free survival than those who did not receive the antibody (89 percent vs. 78 percent; hazard ratio for recurrence or death, 0.42; 95 percent confidence interval, 0.21 to 0.83; P=0.01). Docetaxel was associated with more adverse effects than was vinorelbine. Trastuzumab was not associated with decreased left ventricular ejection fraction or cardiac failure. CONCLUSIONS: Adjuvant treatment with docetaxel, as compared with vinorelbine, improves recurrence-free survival in women with early breast cancer. A short course of trastuzumab administered concomitantly with docetaxel or vinorelbine is effective in women with breast cancer who have an amplified HER2/neu gene. (International Standard Randomised Controlled Trial number, ISRCTN76560285.).

Analysis of Variance↗
PubMed2006

A conditionally replicative adenovirus that codes for a TK-GFP fusion protein (Ad5Delta24TK-GFP) for evaluation of the potency of oncolytic virotherapy combined with molecular chemotherapy.

The utility of conditionally replicative adenoviruses (CRAds) in cancer gene therapy is based on their ability to destroy tumor cells by oncolysis. However, in order to achieve adequate therapeutic response, CRAds have to spread through the tumor tissue by replication. Thus, to study the potency of these viruses to replicate and penetrate in tumors, we created a herpes simplex virus type 1 thymidine kinase-green fluorescent protein fusion gene (TK-GFP) encompassing CRAd (Ad5Delta24TK-GFP), whose tumor selectivity is mediated by a retinoblastoma (Rb)-binding site mutation. In addition, we evaluated the oncolytic efficacy of Ad5Delta24TK-GFP in combination with the TK/ganciclovir (GCV) system. Based on our results, Ad5Delta24TK-GFP replicates in cancer cells resulting in oncolysis and can efficiently penetrate into tumors. Additionally, the combination of GCV with Ad5Delta24TK-GFP augmented cell death in vitro but this was not observed in vivo: tumor growth was significantly reduced by oncolysis when compared to non-replicative virus (p<0.001), but administration of GCV did not significantly enhance oncolysis. This suggests that in certain conditions, TK/GCV-mediated cell killing may be counterproductive to replication and oncolysis, which on the other hand might be useful feature for clinical trials in case of replication-associated toxicity.

Adenoviridae↗
PubMed2005

SMAD4 levels and response to 5-fluorouracil in colorectal cancer.

We have recently reported that low tumor levels of SMAD4, a key mediator of transforming growth factor-beta superfamily signaling, can predict the probability of recurrence in patients with Dukes C colorectal cancer who had surgery as the only form of treatment. However, standard treatment for Dukes C colorectal cancer patients currently involves the administration of 5-fluorouracil (5-FU)-based adjuvant chemotherapy after surgery. Approximately 30% to 40% of these patients present with recurrence and die within 5 years, and there is great need for markers capable of predicting poor prognosis after the combined surgery/adjuvant treatment. In this study, we evaluate the prognostic value of SMAD4 in patients treated with surgery and 5-FU-based adjuvant therapy. We used immunohistochemistry and quantitative real-time reverse transcription-PCR to measure the levels of SMAD4 protein and mRNA expression in the primary tumors and a number of lymph node metastases from a series of 75 Dukes C colorectal cancer patients with at least 6 years of follow-up. Patients with tumors expressing low levels of SMAD4 protein or mRNA showed significantly shorted disease-free and overall survival than patients with high tumor levels of SMAD4. The median survival of patients with low SMAD4 protein or mRNA tumor levels was 1.4 and 1.2 years, respectively, whereas patients with high SMAD4 tumor level had a median survival of >9.3 years. In addition, the protein and mRNA levels of SMAD4 in lymph node metastases was significantly lower than in primary tumors (P = 0.006). In contrast, allelic imbalance in chromosome 18q21 was of no prognostic significance in these patients. In conclusion, low SMAD4 tumor levels identified a subset of patients with poor prognosis following surgery and 5-FU-based adjuvant therapy; therefore, these patients could be good candidates to receive combined treatment with additional chemotherapeutic agents such as CPT-11 and/or oxaliplatin.

Allelic Imbalance↗
PubMed2005

A fiber-modified, secretory leukoprotease inhibitor promoter-based conditionally replicating adenovirus for treatment of ovarian cancer.

PURPOSE: The use of conditionally replicating adenoviruses (CRAD) is dependent on molecular differences between tumor cells and nontumor cells. Transcriptional targeting of CRAD replication via tumor-specific promoters is an effective way to control replication regulation. Genetic fiber pseudotyping is an approach for circumventing low expression of the primary adenovirus serotype 5 (Ad5) receptor by using the distinct adenovirus serotype 3 (Ad3) receptor for entry into and subsequent killing of ovarian cancer cells. EXPERIMENTAL DESIGN: In this study, we constructed a fiber-modified CRAD containing the secretory leukoprotease inhibitor (SLPI) promoter to control viral replication via the E1A gene (Ad5/3SLPI). To evaluate the liver toxicity of chimeric 5/3 fiber-modified CRADs, we compared Ad5/3SLPI with Ad5/3Cox-2L, a CRAD with E1A under control of the Cox-2 promoter, and Ad5/3Delta24, a CRAD that replicates in cancer cells inactive in the retinoblastoma/p16 pathway by use of an in vivo hepatotoxicity model and by a model system that uses slices of human liver. RESULTS: We show efficient viral replication and oncolysis of Ad5/3SLPI in both multiple ovarian cancer cell lines and primary tumor cell spheroids as well as therapeutic efficacy in an orthotopic mouse model of peritoneal carcinomatosis. Ad5/3SLPI showed significantly decreased liver toxicity compared with other 5/3 fiber-modified control vectors examined. CONCLUSIONS: In summary, Ad5/3SLPI is a promising vector candidate for treating metastatic ovarian cancer and showed robust virus replication, oncolysis, and in vivo therapeutic efficacy. Ad5/3SLPI showed comparatively low liver toxicity and therefore holds potential for patient use in the clinic.

Adenoviridae↗
PubMed2005

VP22 does not significantly enhance enzyme prodrug cancer gene therapy as a part of a VP22-HSVTk-GFP triple fusion construct.

BACKGROUND: VP22 is a herpes simplex virus type 1 (HSV-1) tegument protein that has been suggested to spread from cell to cell, alone or as a part of fusion proteins. Creating controversy, some reports indicate that VP22 cannot facilitate significant intercellular spreading. To study the capacity of VP22 to cause spreading and enhance thymidine kinase/ganciclovir cancer gene therapy, we constructed a novel triple fusion protein containing VP22, HSV thymidine kinase and green fluorescent protein (VP22-Tk-GFP). This fusion protein has three functional domains in the same polypeptide, thus making it possible to reliably compare the causality between transduction rate and cell killing efficiency in vitro and in vivo. METHODS: VP22-Tk-GFP was cloned into lenti- and adenoviral vectors and used for expression studies, analyses for VP22-mediated protein spreading, and to study the effect of VP22 to thymidine kinase/ganciclovir-mediated cytotoxicity. The function of VP22-Tk-GFP was also investigated in vivo. RESULTS: The triple fusion protein was expressed correctly in vitro, but intercellular trafficking was not observed in any of the studied cell lines. However, under certain conditions, VP22-Tk-GFP sensitized cells more efficiently to ganciclovir than Tk-GFP. In vivo there was a trend for increased inhibition of tumor growth with VP22-Tk-GFP when ganciclovir was present, but the difference with Tk-GFP was not statistically significant. CONCLUSIONS: Based on our results, VP22 fusion proteins do not seem to traffic intercellularly at detectable levels in most tumor cell types. Even though VP22 enhanced cytotoxicity in one cell line in vitro, the effect in vivo was modest. Therefore, our results do not support the utility of VP22 as an enhancer of enzyme prodrug cancer gene therapy.

Adenoviridae↗
PubMed2005

Adenoviruses with an RGD-4C modification of the fiber knob elicit a neutralizing antibody response but continue to allow enhanced gene delivery.

OBJECTIVE: The purpose of this study was to investigate the effect of preexisting neutralizing antibody (NAbs) in naive mice and the effect of induced NAbs in mice immunized with either an RGD or nonmodified Ad5 vector on the transduction efficiency of adenoviral vectors. METHODS: BALB/c mice were immunized with Ad5LucRGD, with the unmodified Ad5Luc1, or with Opti-MEM intraperitoneally (ip) from one to three times. Sera were collected on day 27 and serially diluted to block Ad5Luc1 or Ad5LucRGD prior to infection of SKOV3.ip1 human ovarian carcinoma cells with these same vectors. Forty-eight hours post Ad infection, a luciferase assay was performed to determine the titer of NAbs. RESULTS: Luciferase assay data showed that the gene transfer efficacy of Ad5LucRGD was 1.56-fold higher than Ad5Luc1 in the presence of serum from naive mice. In the presence of serum from Ad5Luc1-challenged mice, the transduction efficiency of Ad5LucRGD was 3.27-fold higher (single challenge) and 4.2-fold higher (triple challenge) than Ad5Luc1. In the presence of serum from Ad5LucRGD-challenged mice, the transduction efficiency of Ad5LucRGD was 2.24-fold higher (single challenge) and 2.53-fold higher (triple challenge) than Ad5Luc1. CONCLUSION: The RGD-modified human Ad vectors appear to be less recognizable than unmodified Ad to preexisting NAbs in mouse models. RGD-modified Ad vectors also appear to elicit a relatively lower level of NAbs that may also contribute to the higher gene transduction efficiency of these modified vectors. Therefore, RGD-modified Ad vectors may be reagents of clinical utility in the context of preformed anti-Ad immunity and in the setting of repetitive dosing.

Adenoviridae↗
PubMed2005

Gene-expression profiling predicts recurrence in Dukes' C colorectal cancer.

BACKGROUND & AIMS: Although approximately 50% of Dukes' C colorectal cancer patients are surgically cured, it is currently not possible to distinguish these patients from those at high risk of recurrence. The recent advent of routine adjuvant chemotherapy for these patients has greatly complicated the identification of new markers predicting the response to surgery, which is now reliant on archived materials. Microarray analysis allows fine tumor classification but cannot be used with paraffin-embedded archival samples. METHODS: We used microarray analysis of a unique set of fresh-frozen tumor samples from Dukes' C patients who had surgery as the only form of treatment to identify molecular signatures that characterize tumors from patients with good and bad prognosis. RESULTS: Unsupervised hierarchical clustering and a K-nearest neighbors-based classifier identified groups of patients with significantly different survival (P = .019 and P = .0001). Expression profiling outperformed previously reported genetic markers of prognosis such as TP53 and K-RAS mutational status and allelic imbalance in chromosome 18q, which were of limited prognostic power in this study. Functional categories significantly enriched in gene-expression differences included protein transport and folding. The prognostic potential of the RAS homologue RHOA, one of the most differentially expressed genes, was further investigated using immunohistochemistry and a tissue microarray containing 137 independent Dukes' C tumor samples. Reduced RHOA expression was associated with significantly shorter survival (P = .01). CONCLUSIONS: This study shows that gene-expression profiling of surgical tumor samples can predict recurrence in Dukes' C patients. Therefore, this approach could be used to guide decisions concerning the clinical management of these patients.

Aged↗
PubMed2005

Adenoviruses for treatment of cancer.

Most cases of cancer, when detected at an advanced stage, cannot be cured with conventional therapeutic modalities. Therefore, novel targeted approaches such as gene therapy are needed. Nevertheless, while the safety record of gene therapy for cancer has been excellent with more than a thousand patients treated without mortality related to the therapy, clinical efficacy has so far been limited. Moreover, it has become evident that clinical efficacy is partly determined by efficacy of gene delivery. Most adenoviruses used for gene therapy have been based on serotype 5 (Ad5). Unfortunately, recent data suggest that the primary receptor, the coxsackie-adenovirus receptor (CAR) expression in tumors may be highly variable resulting in resistance to adenovirus infection. Consequently, various strategies have been evaluated to modify adenovirus tropism in order to circumvent CAR deficiency, including retargeting complexes or genetic capsid modifications. To further improve tumor penetration and local amplification of the anti-tumor effect, selectively oncolytic agents, e.g. conditionally replicating adenoviruses (CRAds), have been constructed. Infection of tumor cells results in replication, oncolysis, and subsequent release of the virus progeny. Normal tissue is spared due to lack of replication. This review will focus on a discussion of various modifications of adenovirus to achieve efficient anti-tumor effect, and special emphasis will be placed on CRAds in multimodality treatments.

Adenoviridae↗
PubMed2004

Evaluation of a selectively oncolytic adenovirus for local and systemic treatment of cervical cancer.

Treatment options for disseminated cervical cancer remain inadequate. Here, we investigated a strategy featuring Ad5-Delta 24 RGD, an oncolytic adenovirus replication-competent selectively in cells defective in the Rb-p16 pathway, such as most cervical cancer cells. The viral fiber contains an alpha(v)beta(3) and alpha(v)beta(5) integrin-binding RGD-4C motif, allowing coxsackie-adenovirus receptor-independent infection. These integrins have been reported to be frequently upregulated in cervical cancer. Oncolysis of cervical cancer cells was similar to a wild-type control in vitro. In an animal model of cervical cancer, the therapeutic efficacy of Ad5-Delta 24 RGD could be demonstrated for both intratumoral and intravenous application routes. Biodistribution was determined following intravenous administration to mice. Further preclinical safety data were obtained by demonstrating lack of replication of the agent in human peripheral blood mononuclear cells. These results suggest that Ad5-Delta 24 RGD could be useful for local or systemic treatment of cervical cancer in patients with disease resistant to currently available modalities.

Adenoviridae↗
PubMed2004

Modified adenoviruses for cancer gene therapy.

Adenoviral gene therapy is an exciting novel approach for treating cancers resistant to currently available therapies. However, currently there is little evidence supporting significant clinical benefits with replication-incompetent adenoviruses. Recent data suggest that expression of the primary receptor, the coxsackie-adenovirus receptor (CAR), may be highly variable on tumor cells, resulting in resistance to infection. Consequently, various strategies have been evaluated to modify adenovirus tropism in order to circumvent CAR deficiency, including retargeting complexes or genetic capsid modifications. To improve tumor penetration and local amplification on the antitumor effect, selectively oncolytic agents, i.e., conditionally replicating adenoviruses, have been constructed. Infection of tumor cells results in replication, oncolysis and subsequent release of the virus progeny. Normal tissue is spared due to lack of replication. This review focuses on the various modifications that have been investigated for improving the antitumor effect of adenoviral gene therapy.

Adenoviridae↗