Postablation Modulation after Single High-Dose Radiation Therapy Improves Tumor Control via Enhanced Immunomodulation.

PURPOSE: Radiotherapy (RT) is frequently used for local control of solid tumors using equal dose per fraction. Recently, single high-dose radiation has been used for ablation of solid tumors. In this report, we provide a novel immunological basis for radiation dose fractionation consisting of a single high-dose radiotherapy, followed by postablation modulation (PAM) with four daily low-dose fractions (22 Gy + 0.5 Gy × 4) to reprogram the tumor microenvironment by diminishing immune suppression, enabling infiltration of effector cells and increasing efficacy of tumor control. EXPERIMENTAL DESIGN: Palpable 3LL and 4T1 tumors in C57Bl/6 and Balb/c mice were irradiated with the Small-Animal Radiation Research Platform irradiator, and tumor growth and survival were monitored. Immunomodulation of tumor and immune cells in vitro and in vivo characterization of tumor-infiltrating immune effector cells were performed by FACS. For systemic application of PAM-RT, whole-lung irradiation was administered in 4T1-bearing Balb/c mice. RESULTS: We report significant tumor growth delays and increased survival in 3LL tumor-bearing mice with PAM. Primary tumor PAM-RT increased infiltration of immune effector cells and decreased Treg in irradiated tumors and secondary lymphoid organs. In a model of murine metastatic breast cancer (4T1), we demonstrated that systemic PAM-RT to the whole lung, 12 days after primary tumor ablative radiotherapy, increased survival with suppression of pulmonary metastases. CONCLUSIONS: We provide a novel immunologic basis for radiation dose fractionation consisting of a single high dose of radiotherapy followed by daily low-dose PAM-RT fractionation to improve the immunogenic potential of ablative radiotherapy.

0 °C is better?- Thawing temperature optimization study for cancer cryoablation in a mouse model with green fluorescent protein-labeled Lewis lung cancer.

PURPOSE: There are two kinds of thawing temperatures commonly adopted in cancer cryosurgery. We attempted to compare their efficacy differences in this study to optimize the surgical method. METHOD: Forty-five C57BL/6 J mice with GFP-labeled Lewis lung cancer were randomized into three groups (n = 15 for each): control group, T0 group (thawing temperature 0 °C), and T40 group (thawing temperature 40 °C). Cryoablation was performed using a combined surgical system. When the ice ball reached the border of the tumor, they were rewarmed to 0 °C and 40 °C, respectively, using a single freeze-thaw cycle. After the surgery, weight of these mice, length/width and the fluorescence intensity (FI) of the tumors were recorded. All mice were sacrificed on Day 14 after the procedures and their xenografts were excised and weighed immediately. We also checked for pulmonary metastasis, and examined tumor specimens using HE staining. RESULTS: Body weights, tumor volumes and FI in the three groups did not differ significantly at baseline. On Day 14, 39% of the tumors in the T0 group decreased in volume, whereas only 17% in the T40 group did. The average FI in the control group increased by 60%, but declined by 72% in T0 mice and 69% in T40 mice. Tumor inhibition rates were 71.64% in the T0 group and 68.12% in the T40 group. Lung metastases rates and histological changes were compatible between the two intervention groups. CONCLUSION: Using 0 °C as the thawing temperature may have more potential benefits in cryoablation efficacy.

Surgery-induced monocytic myeloid-derived suppressor cells expand regulatory T cells in lung cancer.

While monocytic myeloid-derived suppressor cells (M-MDSCs) have been reported to induce the development of regulatory T cells (Treg), little is known about their correlation with Treg during perioperative period. Here, we demonstrated that the M-MDSCs expressing CD11b+CD33+HLA-DR-CD14+ in lung cancer patients after thoractomy significantly increased in comparison with preoperation, and their accumulation linearly correlated with an increase in Treg. Surgery-induced M-MDSCs, in addition to have high arginase activity, were more efficient in suppressing T-cell proliferation. Furthermore, the surgery-induced Treg expressed high levels of Foxp3, PD-1 and CTLA-4. Surgery-induced M-MDSCs were more potent in expending Treg when cocultured with autologous T cells in vitro. Using a lung metastasis mouse model, we demonstrated that the M-MDSCs at postoperative period were significantly increased and linearly correlated with Treg. We also showed that all-trans retinoic acid significantly inhibited the induction and proliferation of M-MDSCs, suppressed expansion of Treg, and finally prevented tumor metastasis in the mice after tumor resection. Receiver operating characteristic analyses revealed the superiority of surgery-induced M-MDSCs and Treg to those at preoperative period as a prognostic marker for lung cancer patients. Taken together, our results link the presence of surgery-induced M-MDSCs with the emergence of Treg and identify M-MDSCs and Treg derived postoperatively as potential indicators of tumor metastasis.

Optimized magnitude of cryosurgery facilitating anti-tumor immunoreaction in a mouse model of Lewis lung cancer.

BACKGROUND: Cryosurgery has reemerged as a less invasive local treatment with possible immune-regulatory effects. However, the optimal magnitude of cryosurgery for achieving immune-regulatory responses at abscopal tumor sites remains unclear. We aimed to investigate appropriate magnitude of cryosurgery for this goal using a mouse model. METHODS: C57BL/6J mice were inoculated with Lewis lung carcinoma cells or B16 melanoma cells in bilateral flanks. The left-sided tumor was cryoablated with repeated freeze/thaw cycles either once, twice, or thrice. The peritumoral injections of LPS were performed. Abscopal tumor volumes were measured, immunohistochemistry was performed for CD4, CD8, Foxp3, and Ki-67, and proinflammatory cytokines were measured in lavage fluid of cryoablated tumor. RESULTS: The growth rate of the abscopal tumor was slowest in the Cryosurgery ×2 group among the five experimental groups. The proportions of CD4(+) T cells and CD8(+) T cells in the abscopal tumor were also significantly higher in the Cryosurgery ×2 group. The levels of IL-1ß, IL-2, IL-6, IL-12ß, IFN-γ, and TNF-α in the peritumoral lavage fluid in Cryosurgery ×2 + LPS group were significantly increased compared with the other groups. CONCLUSIONS: This study suggested that achievement of approximately 73 % damaged area in the cryoablated tumor by two cycles of cryosurgery generates the most favorable immune-regulatory response for abscopal tumors via activation of anti-tumor immune cells as well as increased secretion of proinflammatory cytokines.

The Application of Cytidyl Guanosyl Oligodeoxynucleotide Can Affect the Antitumor Immune Response Induced by a Combined Protocol of Cryoablation and Dendritic Cells in Lewis Lung Cancer Model.

BACKGROUND Recently, several combined therapeutic strategies and targeted agents have been under investigation for their potential role in lung cancer. The combined administration of dendritic cells (DCs) and immune-adjuvant cytidyl guanosyl oligodeoxynucleotide (CpG-ODN) after cryosurgery has proven to be an effective strategy for treating lung cancer. However, whether the application of CpG-ODN could affect the therapeutic results remained to be further explored. MATERIAL AND METHODS The Lewis lung cancer (LLC)-bearing mice received cryoablation and injection of ex vivo-cultured DCs into the peritumoral zone. Subsequently, CpG-ODN was administered to experimental animals 6 hours, 12 hours, and 24 hours after DC injection. The mice in the control group received coadministration of DCs and CpG-ODN simultaneously. Therapeutic effects were evaluated by survival rates. The resistance to rechallenge of LLC cell was assessed by lung metastasis and in vitro cytotoxicity of splenocytes. Furthermore, T-cell subsets and multiple cytokines (interleukin [IL]-4, -10, and-12; interferon [IFN]-γ; tumor necrosis factor [TNF]-α) in the blood were assessed to elucidate the underlying mechanisms. RESULTS Higher ratios of CD4+ and CD8+ T cells and higher levels of IL-12, IFN-γ, and TNF-α were found in the blood of the mice that received CpG-ODN therapy 12 h after DC injection. The cytotoxicity potency of the splenocytes of these mice was significantly higher compared with the mice in other groups. Moreover, the mice receiving CpG-ODN therapy 12 h after DC injection showed significantly better resistance to rechallenge. Compared with the mice in other groups, the mice receiving CpG-ODN therapy 12 h after DC injection were superior in survival rates and antimetastatic effects. CONCLUSIONS Our study suggested that the therapeutic efficacy was closely associated with CpG-ODN administration in the combined therapeutic protocol of cryoablation, DCs, and immune adjuvant. In situ administration of CpG-ODN 12 h after DC injection might be considered the optimum application.

Enhanced tumor growth in the remaining lung after major lung resection.

BACKGROUND: Pneumonectomy induces active growth of the remaining lung in order to compensate for lost lung tissue. We hypothesized that tumor progression is enhanced in the activated local environment. METHODS: We examined the effects of mechanical strain on the activation of lung growth and tumor progression in mice. The mechanical strain imposed on the right lung after left pneumonectomy was neutralized by filling the empty space that remained after pneumonectomy with a polypropylene prosthesis. RESULTS: The neutralization of the strain prevented active lung growth. According to an angiogenesis array, stronger monocyte chemoattractant protein-1 (MCP-1) expression was found in the strain-induced growing lung. The neutralization of the strain attenuated the release of MCP-1 from the lung cells. The intravenous injection of Lewis lung cancer cells resulted in the enhanced development of metastatic foci in the strain-induced growing lung, but the enhanced development was canceled by the neutralization of the strain. An immunohistochemical analysis revealed the prominent accumulation of tumor-associated macrophages in tumors arising in the strain-induced growing lung, and that there was a relationship between the accumulation and the MCP-1 expression status. CONCLUSIONS: Our results suggested that mechanical lung strain, induced by pulmonary resection, triggers active lung growth, thereby creating a tumor-friendly environment. The modification of that environment, as well as the minimizing of surgical stress, may be a meaningful strategy to improve the therapeutic outcome after lung cancer surgery.

The effect of perioperative analgesic drugs omnopon and dexketoprofen on the functional activity of immune cells in murine model of tumor surgery.

We aimed to investigate the effect of perioperative analgesia with nonselective cyclooxygenase-2 inhibitor dexketoprofen and opioid drug omnopon on the functional activity of immune cells in tumor excision murine model. Lewis lung carcinoma cells were transplanted into hind paw of C57/black mice. On the 23th day tumor was removed. Analgesic drugs were injected 30 min before and once a day for 3 days after the surgery. Biological material was obtained a day before, 1 day and 3 days after the tumor removal. IFN-γ, IL-4, IL-10 and TGF-ß mRNA levels in splenic cells were assessed by quantitative real-time RT-PCR. Cytotoxic activity of splenocytes was estimated by flow cytometry. We found that in splenocytes of mice received opioid analgesia IL-10 mRNA level was increased 2.3 times on day one after the surgery compared to preoperative level (P < 0.05), while in dexketoprofen group this parameter did not change. IFN-γ gene expression level on day 3 after tumor removal was 40% higher in splenocytes of dexketoprofen treated mice as compared with omnopon treated animals (P < 0.05). Cytotoxic activity of splenocytes on day 3 postsurgery was (62.2 ± 2.4)% in dexketoprofen against (50.2 ± 3.3)% in omnopon group. In conclusion, perioperative analgesia with cyclooxygenase inhibitor dexketoprofen in contrast to opioid analgesia with omnopon preserves higher functional activity of murine immune cells in the experimental model of tumor surgery.

Non-extended cryoablation could be a new strategy in lung cancer management: An experiment on green fluorescent protein-labeled Lewis lung cancer-bearing mice.

Modern cryoablation has been performed in solid tumor management for more than two decades. Following the surgical spirits, it seems natural to pursue radical procedures in clinical practice, which results in unnecessary adverse effects. The attempt to use non-extended procedure made some marked achievements in practice but was criticized severely, because it was supposed to induce residual tumors, which would trigger the rapid development of cancer. Oncologists favored this procedure, however, claiming that non-extended cryoablation let lung cancer patients have higher quality of lives and longer survivals, in light of clinical observations. Therefore, this study was conducted trying to solve this controversy. In this study, fifty female C57BL/6J mice were grafted green fluorescent protein (GFP)-labeled Lewis lung cancer and randomized into two groups. The bidirectional diameters and fluorescence intensity of tumors, and the body weight of mice were recorded. Two weeks after the intervention, tumor volumes increased 20.95% in the cryoablation group, significantly different from that in the control group; the fluorescence intensity decreased 49.85% in the cryoablation group but increased 125.07% in the control group. Lung metastases could be observed in only 20% of mice in the cryosurgery group, contrasted to 64% in the control group. The non-extended lung cancer cryoablation does induce marginal tumor residuals, but will not trigger rapid tumor development. Inversely, the residual tumor cells are severely struck and the metastases are suppressed after the intervention. It could be a new strategy in lung cancer management, even for patients not in early stage.

Small portable interchangeable imager of fluorescence for fluorescence guided surgery and research.

Fluorescence guided surgery (FGS) is a developing field of surgical and oncologic research. Practically, FGS has shown useful applications in urologic surgery, benign biliary surgery, colorectal cancer liver metastasis resection, and ovarian cancer debulking. Most notably in in cancer surgery, FGS allows for the clear delineation of cancerous tissue from benign tissue. FGS requires the utilization of a fluorescent contrast agent and an intraoperative fluorescence imaging device (IFID). Currently available IFIDs are expensive, unable to work with multiple fluorophores, and can be cumbersome. This study aims to describe the development and utility of a small, cost-efficient, and interchangeable IFID made from commercially available components. Extensive research was done to design and construct a light-weight, portable, and cost-effective IFID. We researched the capabilities, size, and cost of several camera types and eventually decided on a near-infrared (NIR) charged couple device (CCD) camera for its overall profile. The small portable interchangeable imager of fluorescence (SPIIF) is a "scout" IFID system for FGS. The main components of the SPIIF are a NIR CCD camera with an articulating light filter. These components and a LED light source with an attached heat sink are mounted on a small metal platform. The system is connected to a laptop by a USB 2.0 cable. Pixielink © software on the laptop runs the system by controlling exposure time, gain, and image capture. After developing the system, we evaluated its utility as an IFID. The system weighs less than two pounds and can cover a large area. Due to its small size, it is easily made sterile by covering it with any sterile plastic sheet. To determine the system's ability to detect fluorescent signal, we used the SPIIF to detect indocyanine green under ex and in-vivo conditions and fluorescein under ex-vivo conditions. We found the SPIIF was able to detect both ICG and fluorescein under different depths of a semi-opaque colloid. Second, we found that a concentration as low as 0.5 g/ml of indocyanine green dissolved in plasma was detectable. Lastly, in a murine and human cancer model, the SPIIF was able to detect indocyanine green signal within tumors and generate a signal-to-background ratio (SBR) of 3.75. This study shows that a low-cost IFID can be made from commercially available parts. Second, this IFID is capable of in and ex-vivo detection of multiple fluorophores without sacrificing its small size or favorable ergonomics.

Cryoimmunotherapy with local co-administration of ex vivo generated dendritic cells and CpG-ODN immune adjuvant, elicits a specific antitumor immunity.

Cryoablation is a low-invasive surgical procedure for management of malignant tumors. Tissue destruction is obtained by repeated deep freezing and thawing and results in coagulative necrosis and in apoptosis. This procedure induces the release of tumor-associated antigens and proinflammatory factors into the microenvironment. Local administration of immature dendritic cells (DCs) potentiates the immune response induced by cryoablation. To further augment the induction of long-lasting antitumor immunity, we investigated the clinical value of combining cryoimmunotherapy consisting of cryoablation and inoculation of immature DCs with administration of the immune adjuvant, CpG oligodeoxynucleotides. Injection of the murine Lewis lung carcinoma, D122-luc-5.5 that expresses the luciferase gene, results in spontaneous metastases, which can be easily monitored in vivo. The local tumor was treated by the combined treatment. The clinical outcome was assessed by monitoring tumor growth, metastasis in distant organs, overall survival, and protection from tumor recurrence. The nature of the induced T cell responses was analyzed. Combined cryoimmunotherapy results in reduced tumor growth, low metastasis and significantly prolonged survival. Moreover, this treatment induces antitumor memory that protected mice from rechallenge. The underlying suggested mechanisms are the generation of tumor-specific type 1 T cell responses, subsequent induction of cytotoxic T lymphocytes, and generation of systemic memory. Our data highlight the combined cryoimmunotherapy as a novel antitumor vaccine with promising preclinical results. Adjustment of this technique into practice will provide the therapeutic benefits of both, ablation of the primary tumor and induction of robust antitumor and antimetastatic immunity.

Dynamic subcellular imaging of cancer cell mitosis in the brain of live mice.

The ability to visualize cancer cell mitosis and apoptosis in the brain in real time would be of great utility in testing novel therapies. In order to achieve this goal, the cancer cells were labeled with green fluorescent protein (GFP) in the nucleus and red fluorescent protein (RFP) in the cytoplasm, such that mitosis and apoptosis could be clearly imaged. A craniotomy open window was made in athymic nude mice for real-time fluorescence imaging of implanted cancer cells growing in the brain. The craniotomy window was reversibly closed with a skin flap. Mitosis of the individual cancer cells were imaged dynamically in real time through the craniotomy-open window. This model can be used to evaluate brain metastasis and brain cancer at the subcellular level.

The impact of intraoperative vaccination with IL-12 modified autologous tumor cells in the Lewis lung carcinoma mouse model.

PURPOSE: To improve immunological defense of tumors, we investigated the effect of intraoperative vaccination with IL-12 cDNA transfected cells in an autologous mouse tumor model. METHODS: Tumors derived from autologous Lewis lung carcinoma cells were established in C57/BL6 mice. At day seven, the tumors were surgically removed. Simultaneously, the mice were vaccinated intraoperatively with Lewis lung carcinoma cells transfected with an IL-12-encoding pRSC construct or with the empty plasmid, or with dead cells either intrasplenically (i.s.) or subcutaneously (s.c.). Control mice did not obtain vaccination. Tumor re-growth, survival, and metastasis were monitored. Mice with no tumor re-growth underwent a second tumor implantation. The same parameters were examined. RESULTS: After tumor resection and vaccination tumors reappeared in 60.0% of the animals of the control group. Lowest tumor reoccurrence rates of 41.4 and 43.5% were seen in animals receiving IL-12 pRSC cells either i.s. or s.c. Survival tended to be enhanced in all vaccinated animals compared with the control group. Following R0 tumor resection, the rate of tumor-free survivors was highest when IL-12 pRSC cells were given i.s. (73%, control 45%). 37-59% of the mice of the therapy groups did not develop a tumor, that is, they were tumor-free survivors. These mice underwent a second tumor implantation 120 days after tumor resection and vaccination. Tumor growth was significantly delayed in mice receiving IL-12 pRSC cells. CONCLUSIONS: Intraoperative autologous whole-cell vaccination is practicable and proved to have anti-tumor potential, and therefore, it could be an additional option in adjuvant cancer therapy.

Antitumor effect of malaria parasite infection in a murine Lewis lung cancer model through induction of innate and adaptive immunity.

BACKGROUND: Lung cancer is the most common malignancy in humans and its high fatality means that no effective treatment is available. Developing new therapeutic strategies for lung cancer is urgently needed. Malaria has been reported to stimulate host immune responses, which are believed to be efficacious for combating some clinical cancers. This study is aimed to provide evidence that malaria parasite infection is therapeutic for lung cancer. METHODOLOGY/PRINCIPAL FINDINGS: Antitumor effect of malaria infection was examined in both subcutaneously and intravenously implanted murine Lewis lung cancer (LLC) model. The results showed that malaria infection inhibited LLC growth and metastasis and prolonged the survival of tumor-bearing mice. Histological analysis of tumors from mice infected with malaria revealed that angiogenesis was inhibited, which correlated with increased terminal deoxynucleotidyl transferase-mediated (TUNEL) staining and decreased Ki-67 expression in tumors. Through natural killer (NK) cell cytotoxicity activity, cytokine assays, enzyme-linked immunospot assay, lymphocyte proliferation, and flow cytometry, we demonstrated that malaria infection provided anti-tumor effects by inducing both a potent anti-tumor innate immune response, including the secretion of IFN-γ and TNF-α and the activation of NK cells as well as adaptive anti-tumor immunity with increasing tumor-specific T-cell proliferation and cytolytic activity of CD8(+) T cells. Notably, tumor-bearing mice infected with the parasite developed long-lasting and effective tumor-specific immunity. Consequently, we found that malaria parasite infection could enhance the immune response of lung cancer DNA vaccine pcDNA3.1-hMUC1 and the combination produced a synergistic antitumor effect. CONCLUSIONS/SIGNIFICANCE: Malaria infection significantly suppresses LLC growth via induction of innate and adaptive antitumor responses in a mouse model. These data suggest that the malaria parasite may provide a novel strategy or therapeutic vaccine vector for anti-lung cancer immune-based therapy.

Development of tumor-infiltrating CD8+ T cell memory precursor effector cells and antimelanoma memory responses are the result of vaccination and TGF-ß blockade during the perioperative period of tumor resection.

A main goal of cancer immunology research is the formation of Ag-specific memory T cell immunity capable of activation upon tumor re-encounter. The requirements necessary to overcome the inhibitory signals present in the tumor microenvironment and form such memory T cell responses are unknown. In contrast to previous studies targeting tumors expressing highly immunogenic model Ags, we demonstrate that alleviating tumor-induced suppression along with vaccination against authentic Ags during the perioperative period provides long-lasting protection against a highly suppressive and poorly immunogenic melanoma. In this study, we employed DNA vaccination with an immunologically optimized mouse melanoma-shared Ag, Trp1ee/ng, combined with systemic TGF-ß blockade during the perioperative period of primary tumor resection, to confer protection against B16 melanoma, and against JBRH, an independently derived melanoma unrelated to B16. Importantly, we demonstrate that correlative to memory responses, perioperative immunotherapy increases the formation of tumor-infiltrating and tumor-reactive CD8(+) T cells expressing low levels of the transcription factor T-bet, defined as memory precursor effector cells. We show that conditions for an immunologically fertile environment are met when TGF-ß blockade and vaccination are applied during the perioperative period of primary tumor resection. These findings address limitations of current CD8(+) T cell immunotherapies against cancer by generating effective CD8(+) T cell memory recall responses.

Effect of endostatin on preventing postoperative progression of distant metastasis in a murine lung cancer model.

AIMS AND BACKGROUND: The relapse and metastasis of cancer remain a predominant cause of death after surgical removal of the primary tumor. There is a positive linkage between the postoperative upregulation of systemic angiogenic activity and distant tumor metastasis. In the present study, we established a spontaneous metastasis model and investigated whether antiangiogenic therapy using endostatin could prevent the progression of distant metastasis after removal of the primary tumor. METHODS: Female C57BL/6 mice were implanted subcutaneously with 1 × 106 Lewis lung cancer cells. Twenty days after implantation of the cancer cells, the primary tumor was removed and the mice were randomly divided into three groups. The NS group received normal saline, the L-ES group received 3 mg/kg endostatin, and the H-ES group received 20 mg/kg endostatin intravenously daily for 10 days. The effect of endostatin on lung metastases and the survival time of the mice were observed. Flow cytometry and immunohistochemistry were carried out to assess the angiogenic activity. The serum endostatin levels in peripheral blood were measured using an enzyme-linked immunosorbent assay. RESULTS: The mean number of metastatic pulmonary nodules and the mean net lung weight in the NS, L-ES and H-ES groups was 10.2, 2.8 and 4.0, and 0.55 g, 0.31 g and 0.36 g, respectively. The difference between the NS group and the endostatin-treated groups was statistically significant (P <0.05). The endostatin-treated mice showed prolonged overall survival (P <0.05). Compared with the NS group, the endostatin-treated groups had lower levels of circulating endothelial cells in peripheral blood and showed a decrease in microvessel density in the metastatic tumors, with a more marked reduction in the L-ES group (P <0.05). The systemic presence of endostatin was gradually increased with the continued administration of endostatin to the mice. CONCLUSIONS: Antiangiogenic therapy with endostatin is effective in inhibiting the postoperative progression of distant metastasis.

Improving survival rates in two models of spontaneous postoperative metastasis in mice by combined administration of a beta-adrenergic antagonist and a cyclooxygenase-2 inhibitor.

Clinical practice does not consider perioperative paracrine and neuroendocrine stress responses as risk factors for cancer recurrence, although recent animal studies provided supportive evidence. Suggested mechanisms include the effects of stress-hormones on tumor cells and on host physiology. In this study, in mice undergoing primary tumor excision, we tested the survival-enhancing potential of perioperative blockade of catecholamines and prostaglandins, and studied potential mediating mechanisms. C57BL/6J mice were inoculated intrafootpad with syngeneic B16F10.9-melanoma or Lewis lung carcinoma, and the paw was amputated when a developing tumor exceeded 100 microl. The clinically used beta-adrenergic antagonist propranolol, and/or the cyclooxygenase-2 inhibitor etodolac, were administered once before amputation, and recurrence-free survival was monitored. In different studies, NK cytotoxicity, leukocytes' molecular functional markers, and vascular endothelial growth factor secretion by tumor cells were studied in the context of surgery and drug treatments. The findings indicated that the combination of propranolol and etodolac, but neither drug alone, significantly and markedly improved survival rates in both tumor models, and was as effective as established immunostimulatory agents (IL-12 and polyinosinic-polycytiylic acid). Surgery markedly reduced NK cytotoxicity and NK cell expression of Fas ligand and CD11a, reduced all circulating lymphocyte-subtype concentrations, and increased corticosterone levels. Propranolol and etodolac administration counteracted these perturbations. B16 and 3LL secreted vascular endothelial growth factor in vitro, but secretion was not affected by catecholamine agonists, prostaglandins, corticosterone, propranolol, or etodolac. Overall, propranolol and etodolac administration, which could be applied perioperatively in most cancer patients with minimal risk and low cost, has counteracted several immunologic and endocrinologic perturbations and improved recurrence-free survival rates in mice undergoing primary tumor excision.

Prevention of in vivo lung tumor growth by prolonged local delivery of hydroxycamptothecin using poly(ester-carbonate)-collagen composites.

Local tumor recurrence has a major impact on long-term patient survival following the surgical treatment of most cancers, and this is especially true with lung cancer. Consequently, methods to deliver chemotherapeutics locally at a lung tumor resection margin would be beneficial since: 1) systemic treatment approaches are ineffective or highly toxic; 2) the incidence of local recurrence does not warrant universal treatment of all patients with a highly morbid systemic therapy; and 3) surgical resection of recurrent disease is not an option and alternative rescue therapies are generally unsuccessful. To begin to meet this clinical need, we have prepared poly(glycerol monostearate-co-epsilon-caprolactone) films as a controlled, prolonged, and low dose delivery matrix for the potent anticancer agent 10-hydroxycamptothecin (HCPT). These drug-loaded films were applied to a collagen-based scaffold clinically indicated for the mechanical buttressing of lung tissue following surgical resection, resulting in a flexible composite that can be secured to the tissue that releases HCPT over seven weeks and thereby prevents the local growth and establishment of Lewis lung carcinoma tumors in vivo (a freedom of local tumor growth of 86%). In comparison, all animals treated with a larger intravenous dose of HCPT or unloaded composites developed rapid local tumors.

Licorice preparations improve efficiency of chemotherapy and surgical treatment of transplanted tumors.

Experiments on animals with Lewis lung carcinoma and Ehrlich tumor showed that licorice (glycyrrhiza) extract and glyciram prepared from this plant improved the antitumor effect of cyclophosphamide. Glyciram reduced the toxic effect of the cytostatic on peripheral blood leukocytes. Licorice extract inhibited the growth of Ehrlich tumor and development of metastases in mice with Lewis lung carcinoma. Glyciram administered to mice after removal of Lewis lung carcinoma produced an antimetastatic effect and prevented relapses.

Noninvasive assessment of tumor vasculature response to radiation-mediated, vasculature-targeted therapy using quantified power Doppler sonography: implications for improvement of therapy schedules.

OBJECTIVE: Stereotactic radiotherapy (ablative radiation) is a modality that holds considerable promise for effective treatment of intracranial and extracranial malignancies. Although tumor vasculature is relatively resistant to small fractionated doses of ionizing radiation, large ablative doses of ionizing radiation lead to effective demise of the tumor vasculature. The purpose of this study was (1) to noninvasively monitor and compare tumor physiologic parameters in response to ablative radiation treatments and (2) to use these noninvasive parameters to optimize the schedule of administration of radiation therapy. METHODS: Lewis lung carcinoma tumors were implanted into C57BL/6 mice and treated with ablative radiation. The kinetics of change in physiologic parameters of a response to single-dose 20-Gy treatments was measured. Parameters studied included tumor blood flow, apoptosis, and proliferation rates. Serial tumor sections were stained to correlate noninvasive Doppler assessment of tumor blood flow with microvasculature histologic findings. RESULTS: A single administration of 20 Gy led to an incomplete tumor vascular response, with subsequent recovery of tumor blood flow within 4 days after treatment. Sustained reduction of tumor blood flow by administering the successive ablative radiation treatment before tumor blood flow recovery led to a 3-fold tumor growth delay. The difference in tumor volumes at each measurement time point (every 2 days) was statistically significant (P=.016). CONCLUSIONS: This study suggests a rational design of schedule optimization for radiation-mediated, vasculature-directed treatments guided by noninvasive assessment of tumor blood flow levels to ultimately improve the tumor response.

Cytokine-containing gelfoam implants at a postsurgical tumor excision site to stimulate local immune reactivity.

We previously demonstrated increased numbers of CD34(+) progenitor cells in the peripheral blood of tumor bearers. Also demonstrated was the feasibility of chemoattracting these cells by sponge implants containing VEGF. The present study used a murine Lewis lung carcinoma (LLC) model to test if CD34(+) cells that are chemoattracted to a tumor excision site can be differentiated in situ into dendritic cells and whether this leads to increased local immune reactivity. After surgically excising established LLC tumors, mice received at the excision site gelatin sponge implants containing VEGF to chemoattract CD34(+) cells, and/or GM-CSF plus SCF to induce CD34(+) cell differentiation into dendritic cells. In some studies, lysates of GFP-transfected LLC cells (LLC(GFP)) were also included in the implants as a source of tumor antigen. After 2 weeks, implants and local lymph nodes were removed and analyzed. Implants containing VEGF, GM-CSF/SCF or VEGF/GM-CSF/SCF had a higher proportion of CD34(+) cells compared to control implants. However, the number of dendritic cells was higher in implants containing GM-CSF/SCF or VEGF/GM-CSF/SCF than those containing either VEGF or diluent. Regional lymph node from mice containing GM-CSF/SCF or VEGF/GM-CSF/SCF implants showed increased dendritic cell levels. However, when lysates from LLC(GFP) were added to the implants, the highest proportion of dendritic cells associated with GFP was in lymph nodes of mice containing GM-CSF/SCF implants. Lymph node cells from mice with GM-CSF/SCF or VEGF/GM-CSF/SCF had a higher level of proliferation and IFN-gamma secretion in response to in vitro LLC lysate challenge, with the greatest response being from lymph node cells of mice with GM-CSF/SCF implants. These results suggest the feasibility of using GM-CSF/SCF-containing implants to increase dendritic cell levels, uptake of tumor antigens, trafficking to lymph nodes and stimulation of immune reactivity at tumor excision sites with residual tumor.