How to improve the immunogenicity of chemotherapy and radiotherapy

Shifting cold to hot tumors by nanoparticle-loaded drugs and products

Cold tumors lack antitumor immunity and are resistant to therapy, representing a major challenge in cancer medicine. Because of the immunosuppressive spirit of the tumor microenvironment (TME), this form of tumor has a low response to immunotherapy, radiotherapy, and also chemotherapy. Cold tumors have low infiltration of immune cells and a high expression of co-inhibitory molecules, such as immune checkpoints and immunosuppressive molecules. Therefore, targeting TME and remodeling immunity in cold tumors can improve the chance of tumor repression after therapy. However, tumor stroma prevents the infiltration of inflammatory cells and hinders the penetration of diverse molecules and drugs. Nanoparticles are an intriguing tool for the delivery of immune modulatory agents and shifting cold to hot tumors. In this review article, we discuss the mechanisms underlying the ability of nanoparticles loaded with different drugs and products to modulate TME and enhance immune cell infiltration. We also focus on newest progresses in the design and development of nanoparticle-based strategies for changing cold to hot tumors. These include the use of nanoparticles for targeted delivery of immunomodulatory agents, such as cytokines, small molecules, and checkpoint inhibitors, and for co-delivery of chemotherapy drugs and immunomodulatory agents. Furthermore, we discuss the potential of nanoparticles for enhancing the efficacy of cancer vaccines and cell therapy for overcoming resistance to treatment.

Novel radionuclide therapy combinations in prostate cancer

Prostate cancer remains the commonest cancer diagnosed in males and a leading cause of cancer-related death. Men with metastatic castration-resistant prostate cancer (mCRPC) who have progressed on chemotherapy and androgen receptor pathway inhibitors (ARPI) have limited treatment options, significant morbidity, and poor outcomes. Prostate-specific membrane antigen (PSMA)-directed radionuclide therapy (RNT) is emerging as an efficacious and well-tolerated therapy; however, disease progression is universal. Several ongoing RNT trials focus on combination strategies to improve efficacy and durability of treatment response, including combinations with ARPIs, chemotherapy, immunotherapy, and targeted therapies. Further, efforts are underway to expand the role of PSMA-directed RNT to earlier stages of disease including hormone-sensitive and localized prostate cancer. In this review, we discuss the rationale and ongoing RNT combination therapeutic trials in prostate cancer and summarize the efficacy and toxicity associated with RNT.

Vaccine-like nanomedicine for cancer immunotherapy

The successful clinical application of immune checkpoint blockade (ICB) and chimeric antigen receptor T cells (CAR-T) therapeutics has attracted extensive attention to immunotherapy, however, their drawbacks such as limited specificity, persistence and toxicity haven't met the high expectations on efficient cancer treatments. Therapeutic cancer vaccines which instruct the immune system to capture tumor specific antigens, generate long-term immune memory and specifically eliminate cancer cells gradually become the most promising strategies to eradicate tumor. However, the disadvantages of some existing vaccines such as weak immunogenicity and in vivo instability have restricted their development. Nanotechnology has been recently incorporated into vaccine fabrication and exhibited promising results for cancer immunotherapy. Nanoparticles promote the stability of vaccines, as well as enhance antigen recognition and presentation owing to their nanometer size which promotes internalization of antigens by phagocytic cells. The surface modification with targeting units further permits the delivery of vaccines to specific cells. Meanwhile, nanocarriers with adjuvant effect can improve the efficacy of vaccines. In addition to classic vaccines composed of antigens and adjuvants, the nanoparticle-mediated chemotherapy, radiotherapy and certain other therapeutics could induce the release of tumor antigens in situ, which therefore effectively simulate antitumor immune responses. Such vaccine-like nanomedicine not only kills primary tumors, but also prevents tumor recurrence and helps eliminate metastatic tumors. Herein, we introduce recent developments in nanoparticle-based delivery systems for antigen delivery and in situ antitumor vaccination. We will also discuss the remaining opportunities and challenges of nanovaccine in clinical translation towards cancer treatment.

Immunotherapy plus stereotactic body radiation therapy or whole-brain radiation therapy in brain metastases

Aim: To investigate the association of stereotactic radiation therapy (SRT) or whole-brain radiation therapy (WBRT) plus immunotherapy with the overall survival (OS) of cancer patients with brain metastases (BMs) regardless of the primary cancer. Patients & methods: Patients diagnosed with BMs were identified from the National Cancer Database. Results: A total of 34,286 patients were included. SRT plus immunotherapy was associated with improved OS compared with SRT without immunotherapy (hazard ratio: 0.774; 95% CI: 0.687-0.872; p < 0.001), and WBRT plus immunotherapy was associated with improved OS compared with WBRT without immunotherapy (hazard ratio: 0.724; 95% CI; 0.673-0.779; p < 0.001). Conclusion: SRT plus immunotherapy was associated with improved OS compared with SRT. WBRT plus immunotherapy was associated with improved OS compared with WBRT in cancer patients who had BMs at the time of primary cancer diagnosis.

The Association of Immunotherapy With the Overall Survival of Inoperable Stage III Non-small Cell Lung Cancer Patients Who Do Not Receive Chemoradiation

Immunotherapy has been approved for stage III non-small cell lung cancer (NSCLC) as consolidation therapy after chemoradiation in patients whose disease does not progress after chemoradiation. However, many patients do not receive chemoradiation due to either the drugs' side effects or poor performance status. This study's objective is to investigate the association of immunotherapy combined with chemotherapy or Radiotherapy (RT) with the overall survival (OS) of stage III NSCLC patients who do not receive chemoradiation. Patients with stage III NSCLC who received either chemotherapy or RT with or without immunotherapy were identified from NCDB. The Cox proportional hazard regression analysis was implied to assess the effect of immunotherapy on survival after adjusting the model for age at diagnosis, race, sex, education, treatment facility type, insurance status, comorbidity score, histology year of diagnosis, and treatment types, such as chemotherapy and radiation therapy. The final analysis included 32,328 patients, among whom 3,205 (9.9%) received immunotherapy. In the multivariable analysis adjusted for all the factors previously mentioned, immunotherapy was associated with significantly improved OS (HR: 0.76, CI: 0.71-0.81) compared with no immunotherapy. Treatment with chemotherapy plus immunotherapy was significantly associated with improved OS (HR: 0.83, CI: 0.77-0.90) compared with chemotherapy without immunotherapy. Further, RT plus immunotherapy was associated with significantly improved OS (HR: 0.62, CI: 0.54-0.70) compared with RT alone. In this comprehensive analysis, the addition of immunotherapy to chemotherapy or radiotherapy was associated with improved OS compared with chemotherapy or radiation therapy without immunotherapy in stage III NSCLC patients.

Carbon ion radiotherapy triggers immunogenic cell death and sensitizes melanoma to anti-PD-1 therapy in mice

Carbon ion radiotherapy (CIRT) is an emerging type of radiotherapy for the treatment of solid tumors. In recent years, evidence accumulated that CIRT improves the therapeutic outcome in patients with otherwise poor response to immune checkpoint blockade. Here, we aimed at identifying the underlying mechanisms of CIRT-induced tumor immunogenicity and treatment efficacy. We used human U2OS osteosarcoma cells for the in vitro assessment of immunogenic cell death and established several in vivo models of melanoma in mice. We treated the animals with conventional radiation, CIRT, PD-1-targeting immune checkpoint blockade or a sequential combinations of radiotherapy with checkpoint blockade. We utilized flow cytometry, polyacrylamide gel electrophoresis (PAGE) and immunoblot analysis, immunofluorescence, immunohistochemistry, as well as enzyme-linked immunosorbent assays (ELISA) to assess biomarkers of immunogenic cell death in vitro. Treatment efficacy was studied by tumor growth assessment and the tumor immune infiltrate was analyzed by flow cytometry and immunohistochemistry. Compared with conventional radioimmunotherapy, the combination of CIRT with anti-PD-1 more efficiently triggered traits of immunogenic cell death including the exposure of calreticulin, the release of adenosine triphosphate (ATP), the exodus of high-mobility group box 1 (HMGB1) as well as the induction of type-1 interferon responses. In addition, CIRT plus anti-PD-1 led to an increased infiltration of CD4⁺, and CD8⁺ lymphocytes into the tumor bed, significantly decreased tumor growth and prolonged survival of melanoma bearing mice. We herein provide evidence that CIRT-triggered immunogenic cell death, enhanced tumor immunogenicity and improved the efficacy of subsequent anti-PD-1 immunotherapy.

The importance of hypoxia in radiotherapy for the immune response, metastatic potential and FLASH-RT

PURPOSE

Hypoxia (low oxygen) is a common feature of solid tumors that has been intensely studied for more than six decades. Here we review the importance of hypoxia to radiotherapy with a particular focus on the contribution of hypoxia to immune responses, metastatic potential and FLASH radiotherapy, active areas of research by leading women in the field.

CONCLUSION

Although hypoxia-driven metastasis and immunosuppression can negatively impact clinical outcome, understanding these processes can also provide tumor-specific vulnerabilities that may be therapeutically exploited. The different oxygen tensions present in tumors and normal tissues may underpin the beneficial FLASH sparing effect seen in normal tissue and represents a perfect example of advances in the field that can leverage tumor hypoxia to improve future radiotherapy treatments.

Bacteria-Based Cancer Immunotherapy

In the past decade, bacteria-based cancer immunotherapy has attracted much attention in the academic circle due to its unique mechanism and abundant applications in triggering the host anti-tumor immunity. One advantage of bacteria lies in their capability in targeting tumors and preferentially colonizing the core area of the tumor. Because bacteria are abundant in pathogen-associated molecular patterns that can effectively activate the immune cells even in the tumor immunosuppressive microenvironment, they are capable of enhancing the specific immune recognition and elimination of tumor cells. More attractively, during the rapid development of synthetic biology, using gene technology to enable bacteria to be an efficient producer of immunotherapeutic agents has led to many creative immunotherapy paradigms. The combination of bacteria and nanomaterials also displays infinite imagination in the multifunctional endowment for cancer immunotherapy. The current progress report summarizes the recent advances in bacteria-based cancer immunotherapy with specific foci on the applications of naive bacteria-, engineered bacteria-, and bacterial components-based cancer immunotherapy, and at the same time discusses future directions in this field of research based on the present developments.

Immune Stimulating Antibody-Photosensitizer Conjugates via Fc-Mediated Dendritic Cell Phagocytosis and Phototriggered Immunogenic Cell Death for KRAS-Mutated Pancreatic Cancer Treatment

Although cetuximab (CTX) is a chimeric epidermal growth factor receptor (EGFR) antibody, the antitumor efficacy of CTX has a negligible effect in patients with Kirsten rat sarcoma 2 viral oncogene homolog (KRAS) mutated pancreatic adenocarcinoma. Given that all extant treatments are ineffective due to the undruggable characteristics of KRAS-mutated cancer, alternative strategies have been investigated. In this work, CTX-conjugated maleimide-polyethylene glycol-chlorin e6 (CMPC) is designed to strengthen its antitumor efficacy. With strong affinity for EGFR overexpressing Aspc-1 cells, CMPC with laser exerts the greatest cytotoxicity (90%) and induction of immunogenic cell death. Through a combination of fragment crystallizable region-mediated antigen uptake by CTX and danger-associated molecular patterns released by photodynamic therapy (PDT), phagocytosis and maturation of dendritic cells treated with CMPC plus laser show dramatic increases. In vivo biodistribution and antitumor effect also demonstrate that CMPC has significant tumor selectivity and tumor ablation efficacy upon laser irradiation. Furthermore, a large number of CD4⁺ , CD8⁺ T cells and mature DCs and natural killer cells are infiltrated in CMPC with laser-treated tumor tissues and tumor-draining lymph nodes, revealing both innate and adaptive cellular immune stimulation. This synergistic effect with CMPC and laser treatment provides an effective approach for pancreatic cancer immunotherapy attributed to both CTX and PDT.

Comparative Proteome Identifies Complement Component 3-Mediated Immune Response as Key Difference of Colon Adenocarcinoma and Rectal Adenocarcinoma

Colorectal cancer (CRC) is one of the most lethal diseases with high morbidity and mortality worldwide. Clinically, tumors located in colon and rectum have diverse prognosis and therapeutic outcome. Here, we performed data mining derived from 20 CRC patient samples to compare proteomic difference between colon adenocarcinoma (COAD) and rectal adenocarcinoma (READ). We found that differential expressed proteins (DEPs) upregulated in COAD were mainly enriched in immune response, moreover, higher immune scores were found in COAD than READ, as calculated by The Cancer Genome Atlas (TCGA) data. To identify the core protein of DEPs with high prognostic value for COAD, we performed topological overlap matrix (TOM) to investigate the hub proteins using 77 immune-relevant DEPs, and identified complement component 3 (C3) as the core protein in the immune-relevant DEPs matrix between the COAD and READ. Moreover, we found that C3 was up-regulated in COAD, and its expression was negatively associated with overall survival of COAD patients but not READ. In conclusion, we identified C3-mediated immune response as key feature to distinguish COAD and READ, and highlighted C3 as potential biomarker with high prognostic value for clinical application, which provided new clue for precise treatment of COAD.

Combining targeted therapy with immunotherapy (interferon-α): Rational, efficacy in gastrointestinal stromal tumor model and implications in other malignancies

Imatinib revolutionized gastrointestinal stromal tumor (GIST) treatment but median-progression-free-survival of unresectable/metastatic disease is < 2 y. B-RAF(V600)-mutated-melanoma responds to vemurafenib dramatically but median-progression-free-survival is < 9 mo. Combining imatinib with immunotherapy (peginterferon α-2b) in GIST showed significant induction of antitumor immunity and highly promising clinical outcomes. This strategy warrants further testing in other malignancies.

Correlation between changes in the number of peripheral blood lymphocytes and survival rate in patients with cervical cancer after radio-chemotherapy

PURPOSE

This study aimed to compare the absolute numbers of various types of lymphocytes in the peripheral blood before and after chemotherapy following radio-chemotherapy in patients with cervical cancer, so as to explore the correlation between the changes in the absolute numbers of peripheral various types of lymphocytes and the overall survival rate of patients.

METHODS

Data of 205 patients with cervical cancer admitted to the hospital from June 2014 to August 2016 were retrospectively analyzed. These patients underwent concurrent radio-chemotherapy, followed by chemotherapy. The absolute numbers of peripheral blood lymphocytes and subtypes were compared before and after re-chemotherapy.

RESULTS

For patients with a good prognosis, the number of lymphocytes, T cells, and cytotoxic T cells (Tc) significantly decreased (P<0.05) after re-chemotherapy, while this phenomenon was not observed in patients with poor prognosis. Kaplan-Meier univariate analysis showed that patients with cervical cancer who had an advanced FIGO stage before treatment, presence of lymph node metastasis, and increased numbers of Tc and T helper cells after re-chemotherapy showed a low 30-month survival rate; the overall log-rank analysis showed significant differences (P<0.05). Multivariate Cox proportional hazards regression analysis, presence of lymph node metastasis: HR=9.718, P=0.002, 95% CI=0.183-0.679; Tc grouping: HR=3.239, P=0.0.072, 95% CI=0.950-03.347; Th group: HR=3.197, P=0.074, 95% CI=0.943-3.564.

CONCLUSIONS

After radio-chemotherapy, in patients with advanced cervical cancer, the change in the numbers of peripheral blood Tc and Th before and after re-chemotherapy was associated with the 30-month overall survival rate of patients. It can be considered as a predictor of the survival of patients with advanced cervical cancer.

Interactions between tumor-derived proteins and Toll-like receptors

Damage-associated molecular patterns (DAMPs) are danger signals (or alarmins) alerting immune cells through pattern recognition receptors (PRRs) to begin defense activity. Moreover, DAMPs are host biomolecules that can initiate a noninflammatory response to infection, and pathogen-associated molecular pattern (PAMPs) perpetuate the inflammatory response to infection. Many DAMPs are proteins that have defined intracellular functions and are released from dying cells after tissue injury or chemo-/radiotherapy. In the tumor microenvironment, DAMPs can be ligands for Toll-like receptors (TLRs) expressed on immune cells and induce cytokine production and T-cell activation. Moreover, DAMPs released from tumor cells can directly activate tumor-expressed TLRs that induce chemoresistance, migration, invasion, and metastasis. Furthermore, DAMP-induced chronic inflammation in the tumor microenvironment causes an increase in immunosuppressive populations, such as M2 macrophages, myeloid-derived suppressor cells (MDSCs), and regulatory T cells (Tregs). Therefore, regulation of DAMP proteins can reduce excessive inflammation to create an immunogenic tumor microenvironment. Here, we review tumor-derived DAMP proteins as ligands of TLRs and discuss their association with immune cells, tumors, and the composition of the tumor microenvironment.

Tumor cells killed by radiotherapy or chemotherapy release signaling molecules that stimulate both immune response and tumor aggressiveness; regulating these molecules could improve treatment efficacy. Tae Heung Kang, Yeong-Min Park, and co-workers at Konkuk University, Seoul, South Korea, have reviewed the role of damage-associated molecular patterns (DAMPs) in immunity and cancer. These signaling molecules act as danger signals, activating immune cells by binding to specific receptors. However, tumor cells have the same receptors, and DAMPs binding triggers chemoresistance and increases invasiveness. The researchers report that although DAMPs can trigger a helpful immune response, they can also cause chronic inflammation, which in turn promotes an immune suppression response, allowing tumors to escape immune detection. Improving our understanding of the functions of different DAMPs could improve our ability to boost the immune response and decrease tumor aggressiveness.

The Association of the Sequence of Immunotherapy With the Survival of Unresectable Pancreatic Adenocarcinoma Patients: A Retrospective Analysis of the National Cancer Database

Background: Immunotherapy has shown great success in various malignancies. However, its efficacy in pancreatic ductal adenocarcinoma (PDAC) remains a challenge, and the lack of understanding about the appropriate timing of immunotherapy with other standard-of-care cancer treatments may be one of the causes. The objective of the current study is to investigate the impact of the timing of immunotherapy with chemotherapy and radiation therapy (RT) on the overall survival (OS) of PDAC patients who did not receive surgical resection of the pancreatic tumor.

Materials and Methods: Patients with pancreatic adenocarcinoma who did not receive surgical resection of the pancreatic tumor were identified from the National Cancer Database (NCDB). Cox proportional hazard models were employed to compare the OS between patients who received immunotherapy with chemotherapy or RT with a different sequence of treatment. The multivariable analysis was adjusted for age of diagnosis, race, sex, place of living, income, education, treatment facility type, insurance status, and year of diagnosis.

Results: In total, 705 patients received chemotherapy and immunotherapy, while 226 received radiation therapy and immunotherapy. In the multivariable analysis, there was no significant difference in the OS of patients who started immunotherapy 31–90 days before the start of chemotherapy with a hazard ratio (HR) of [HR:1.057 (CI: 0.716–1.56; p < 0.781)] and patients who started immunotherapy 91–180 days before the start of chemotherapy [HR: 0.900 (CI: 0.584–1.388; p < 0.635)] compared to patients who started chemotherapy and immunotherapy within 30 days of each other. There was also no significant difference in the OS of patients who started RT> 30 days before the start of immunotherapy [HR: 0.636 (CI: 0.346–1.171; p < 0.146)] and patients who started immunotherapy > 30 days before the start of RT [HR: 0.660 (CI: 0.328–1.329; p < 0.246)] compared to patients who started RT and immunotherapy within 30 days of each other.

Conclusion: The sequence of immunotherapy with chemotherapy or RT was not associated with improved OS. Future studies with a larger subgroup sample size investigating the impact of the timing of immunotherapy with chemotherapy and RT on the OS of PDAC patients who do not receive surgical resection of the pancreatic tumor are needed.

Association of Immunotherapy With Survival Among Patients With Brain Metastases Whose Cancer Was Managed With Definitive Surgery of the Primary Tumor

IMPORTANCE

Immunotherapy has shown significant control of intracranial metastases in patients with melanoma. However, the association of immunotherapy combined with other cancer treatments and overall survival (OS) of patients with brain metastases, regardless of primary tumor site, is unknown.

OBJECTIVE

To explore the association of immunotherapy with OS in patients with cancer and brain metastases who received definitive surgery of the primary site.

DESIGN, SETTING, AND PARTICIPANTS

This comparative effectiveness study included 3112 adult patients in the National Cancer Database from 2010 to 2016 with non-small cell lung cancer, breast cancer, melanoma, colorectal cancer, or kidney cancer and brain metastases at the time of diagnosis and who received definitive surgery of the primary site. Data analysis was conducted from March to April 2020.

EXPOSURES

Treatment groups were stratified as follows: (1) any treatment with or without immunotherapy, (2) chemotherapy with or without immunotherapy, (3) radiotherapy (RT) with or without immunotherapy, and (4) chemoradiation with or without immunotherapy.

MAIN OUTCOMES AND MEASURES

The association of immunotherapy with OS was assessed with Cox proportional hazards regression, adjusted for age at diagnosis, race, sex, place of living, income, education, treatment facility type, primary tumor type, and year of diagnosis.

RESULTS

Of 3112 patients, 1436 (46.14%) were men, 2714 (87.72%) were White individuals, 257 (8.31%) were Black individuals, and 123 (3.98%) belonged to other racial and ethnic groups. The median (range) age at diagnosis was 61 (19-90) years. Overall, 183 (5.88%) received immunotherapy, 318 (10.22%) received chemotherapy alone, 788 (25.32%) received RT alone, and 1393 (44.76%) received chemoradiation alone; 22 (6.47%) received chemotherapy plus immunotherapy, 72 (8.37%) received RT plus immunotherapy, and 76 (5.17%) received chemoradiation plus immunotherapy. In the multivariable analysis, patients who received immunotherapy had significantly improved OS compared with no immunotherapy (hazard ratio, 0.62; 95% CI, 0.51-0.76; P < .001). Treatment with RT plus immunotherapy was associated with significantly improved OS compared with RT alone (hazard ratio, 0.59; 95% CI, 0.42-0.84; P = .003). Chemotherapy plus immunotherapy or chemoradiation plus immunotherapy were not associated with improved OS in the multivariable analysis.

CONCLUSIONS AND RELEVANCE

In this study, the addition of immunotherapy to RT was associated with improved OS compared with radiotherapy alone in patients with brain metastases who received definitive surgery of the primary tumor site.

Unraveling the regulatory role of endoplasmic-reticulum-associated degradation in tumor immunity

During malignant transformation and cancer progression, tumor cells face both intrinsic and extrinsic stress, endoplasmic reticulum (ER) stress in particular. To survive and proliferate, tumor cells use multiple stress response pathways to mitigate ER stress, promoting disease aggression and treatment resistance. Among the stress response pathways is ER-associated degradation (ERAD), which consists of multiple components and steps working together to ensure protein quality and quantity. In addition to its established role in stress responses and tumor cell survival, ERAD has recently been shown to regulate tumor immunity. Here we summarize current knowledge on how ERAD promotes protein degradation, regulates immune cell development and function, participates in antigen presentation, exerts paradoxical roles on tumorigenesis and immunity, and thus impacts current cancer therapy. Collectively, ERAD is a critical protein homeostasis pathway intertwined with cancer development and tumor immunity. Of particular importance is the need to further unveil ERAD's enigmatic roles in tumor immunity to develop effective targeted and combination therapy for successful treatment of cancer.

Impact of Immunotherapy on the Survival of Patients With Cancer and Brain Metastases

Background: Immunotherapy has shown excellent efficacy in various cancers. However, there is a lack of knowledge regarding the significant role of immunotherapy in patients with brain metastases (BMs). The objective of this study was to investigate, using the National Cancer Database, the impact of immunotherapy on the overall survival (OS) of patients with BMs who did not receive definitive surgery of the primary tumor. Patients and Methods: Patients diagnosed with the primary cancer of non–small cell lung cancer, small cell lung cancer, other types of lung cancer, breast cancer, melanoma, colorectal cancer, or renal cancer who had BMs at the time of diagnosis were identified from the National Cancer Database. We assessed OS using a Cox proportional hazards model adjusted for age at diagnosis, sex, race, education level, income level, residential area, treatment facility type, insurance status, Charlson-Deyo comorbidity status, year of diagnosis, primary tumor type, and receipt of chemotherapy, radiation therapy (RT), and/or immunotherapy, because these factors were significantly associated with OS in the univariable analysis. Results: Of 94,215 patients who were analyzed, 3,097 (3.29%) received immunotherapy. In the multivariable analysis, immunotherapy was associated with significantly improved OS (hazard ratio [HR], 0.694; 95% CI, 0.664–0.726; P<.0001) compared with no immunotherapy. Treatment using chemotherapy plus immunotherapy was significantly associated with improved OS (HR, 0.643; 95% CI, 0.560–0.738; P<.0001) compared with chemotherapy without immunotherapy. RT plus immunotherapy was also associated with significantly improved OS (HR, 0.389; 95% CI, 0.352–0.429; P<.0001) compared with RT alone. Furthermore, chemoradiation (CRT) plus immunotherapy was associated with significantly improved OS (HR, 0.793; 95% CI, 0.752–0.836; P<.0001) compared with CRT alone. Conclusions: In this comprehensive analysis, the addition of immunotherapy to chemotherapy, RT, and CRT was associated with significantly improved OS in patients with BMs. The study warrants future clinical trials of immunotherapy in patients with BMs, who have historically been excluded from these trials.

The impact of immunotherapy on the survival of pancreatic adenocarcinoma patients who do not receive definitive surgery of the tumor

Background and Purpose

Immunotherapy has shown great efficacy in many cancers, but its role in pancreatic ductal adenocarcinoma (PDAC) remains unclear. The objective of this study was to investigate the impact of immunotherapy on the overall survival of PDAC patients who did not receive definitive surgery of the pancreatic primary tumor site using the National Cancer Database (NCDB).

Materials and Methods

Patients with pancreatic adenocarcinoma who did not receive surgery were identified from NCDB. Cox proportional hazard models were employed to assess the impact of immunotherapy on survival after adjusting for age at diagnosis, race, sex, place of living, income, education, treatment facility type, insurance status, year of diagnosis, and treatment types such as chemotherapy and radiation therapy.

Results

Of 263,886 patients who were analyzed, 911 (0.35%) received immunotherapy. Among patients who received chemotherapy (101,546), and chemoradiation (30,226) therapy, 555/101,546 (0.55%) received chemotherapy plus immunotherapy, and 299/3,022 (9.9%) received chemoradiation plus immunotherapy. In a multivariable analysis adjusted for the factors mentioned above, immunotherapy was associated with significantly improved OS (HR: 0.866 (0.800–0.937); P < 0.001) compared to no immunotherapy. Chemotherapy plus immunotherapy was significantly associated with improved OS (HR: 0.848 (0.766–0.938); P < 0.001) compared to chemotherapy without immunotherapy. Further, chemoradiation plus immunotherapy was associated with significantly improved OS (HR: 0.813 (0.707–0.936); P < 0.001) compared to chemoradiation alone.

Conclusion

In this study, the addition of immunotherapy to chemotherapy and chemoradiation therapy was associated with significantly improved OS in PDAC patients without definitive surgery. The study warrants future clinical trials of immunotherapy in PDAC.

The impact of immunotherapy on the survival of pancreatic adenocarcinoma patients who received definitive surgery of the pancreatic tumor: a retrospective analysis of the National Cancer Database

BACKGROUND

Immunotherapy has paved the way for new therapeutic opportunities in cancer but has failed to show any efficacy in Pancreatic Adenocarcinoma (PDAC), and its therapeutic role remains unclear. The objective of this study is to examine the impact of immunotherapy in combination with chemotherapy, RT, and chemoradiation on the overall survival (OS) of PDAC patients who received definitive surgery of the tumor using the National Cancer Database (NCDB).

METHODS

Patients with PDAC who received definitive surgery of the pancreatic tumor and were diagnosed between 2004 and 2016 from the NCDB were identified. Cox proportional hazard analysis was used to assess the survival difference between patients who received chemotherapy plus immunotherapy and chemoradiation therapy plus immunotherapy and their counterparts who only receive these treatments without immunotherapy. The multivariable analysis was adjusted for age of diagnosis, race, sex, place of living, income, education, treatment facility type, insurance status, year of diagnosis, and treatment types such as chemotherapy and radiation therapy.

RESULTS

In total, 63,154 PDAC patients who received definitive surgery of the tumor were included in the analysis. Among the 63,154 patients, 636 (1.01%) received immunotherapy. Among patients who received chemotherapy (21,355), and chemoradiation (21,875), 157/21,355 (0.74%) received chemotherapy plus immunotherapy, and 451/21,875 (2.06%) received chemoradiation plus immunotherapy. Patients who received chemoradiation plus immunotherapy had significantly improved median OS compared to patients who only received chemoradiation with an absolute median OS benefit of 5.7 [29.31 vs. 23.66, p < 0.0001] months. In the multivariable analysis, patients who received immunotherapy had significantly improved OS compared to patients who did not receive immunotherapy (HR: 0.900; CI: 0.814-0.995; P < 0.039). Patients who received chemoradiation plus immunotherapy had significantly improved OS compared to their counterparts who only received chemoradiation without immunotherapy (HR: 0.852 CI: 0.757-0.958; P < 0.008).

CONCLUSIONS

In this study, the addition of immunotherapy to chemoradiation therapy was associated with significantly improved OS in PDAC patients who received definitive surgery. The study warrants further future clinical trials of immunotherapy in PDAC.

High dose-rate brachytherapy of localized prostate cancer converts tumors from cold to hot

BACKGROUND

Prostate cancer (PCa) has a profoundly immunosuppressive microenvironment and is commonly immune excluded with few infiltrative lymphocytes and low levels of immune activation. High-dose radiation has been demonstrated to stimulate the immune system in various human solid tumors. We hypothesized that localized radiation therapy, in the form of high dose-rate brachytherapy (HDRBT), would overcome immune suppression in PCa.

METHODS

To investigate whether HDRBT altered prostate immune context, we analyzed preradiation versus postradiation human tissue from a cohort of 24 patients with localized PCa that received HDRBT as primary treatment (RadBank cohort). We performed Nanostring immune gene expression profiling, digital spatial profiling, and high-throughput immune cell multiplex immunohistochemistry analysis. We also resolved tumor and nontumor zones in spatial and bioinformatic analyses to explore the immunological response.

RESULTS

Nanostring immune profiling revealed numerous immune checkpoint molecules (eg, B7-H3, CTLA4, PDL1, and PDL2) and TGFβ levels were increased in response to HDRBT. We used a published 16-gene tumor inflammation signature (TIS) to divide tumors into distinct immune activation states (high:hot, intermediate and low:cold) and showed that most localized PCa are cold tumors pre-HDRBT. Crucially, HDRBT converted 80% of these 'cold'-phenotype tumors into an 'intermediate' or 'hot' class. We used digital spatial profiling to show these HDRBT-induced changes in prostate TIS scores were derived from the nontumor regions. Furthermore, these changes in TIS were also associated with pervasive changes in immune cell density and spatial relationships-in particular, between T cell subsets and antigen presenting cells. We identified an increased density of CD4+ FOXP3+ T cells, CD68+ macrophages and CD68+ CD11c+ dendritic cells in response to HDRBT. The only subset change specific to tumor zones was PDL1- macrophages. While these immune responses were heterogeneous, HDRBT induced significant changes in immune cell associations, including a gained T cell and HMWCK+ PDL1+ interaction in tumor zones.

CONCLUSION

In conclusion, we showed HDRBT converted "cold" prostate tumors into more immunologically activated "hot" tissues, with accompanying spatially organized immune infiltrates and signaling changes. Understanding and potentially harnessing these changes will have widespread implications for the future treatment of localized PCa, including rational use of combination radio-immunotherapy.

Type I interferons and endoplasmic reticulum stress in health and disease

Type I interferons (IFNs) comprise of pro-inflammatory cytokines created, as well as sensed, by all nucleated cells with the main objective of blocking pathogens-driven infections. Owing to this broad range of influence, type I IFNs also exhibit critical functions in many sterile inflammatory diseases and immunopathologies, especially those associated with endoplasmic reticulum (ER) stress-driven signaling pathways. Indeed, over the years accumulating evidence has indicated that the presence of ER stress can influence the production, or sensing of, type I IFNs induced by perturbations like pattern recognition receptor (PRR) agonists, infections (bacterial, viral or parasitic) or autoimmunity. In this article we discuss the link between type I IFNs and ER stress in various diseased contexts. We describe how ER stress regulates type I IFNs production or sensing, or how type I IFNs may induce ER stress, in various circumstances like microbial infections, autoimmunity, diabetes, cancer and other ER stress-related contexts.

Tumor-targeted IL-12 combined with tumor resection yields a survival-favorable immune profile

BACKGROUND

Although accumulated evidence provides a strong scientific premise for using immune profiles to predict survival in patients with cancer, a universal immune profile across tumor types is still lacking, and how to achieve a survival-associated immune profile remains to be evaluated.

METHODS

We analyzed datasets from The Cancer Genome Atlas to identify an immune profile associated with prolonged overall survival in multiple tumor types and tested the efficacy of tumor cell-surface vimentin-targeted interleukin 12 (ttIL-12) in inducing that immune profile and prolonging survival in both mouse and patient-derived xenograft tumor models.

RESULTS

We identified an immune profile (IFNγHiCD8HiFOXP3LowCD33Low) associated with prolonged overall survival across several human tumor types. ttIL-12 in combination with surgical resection of the primary tumor transformed tumors to this immune profile. Intriguingly, this immune profile transformation led to inhibition of metastasis and to prolonged survival in both mouse and patient-derived xenograft malignant models. Wild-type IL-12 combined with surgery was significantly less effective. In the IL-12-sensitive C3H mouse strain, in fact, wild-type IL-12 and surgery resulted in shorter overall survival than in mice treated with control pDNA; this surprising result is believed to be attributable to IL-12 toxicity, which was absent in the mice treated with ttIL-12. The ttIL-12-induced immune profile associated with longer overall survival was also associated with a greater accumulation of CD8+ T cells and reduced infiltration of regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages. The underlying mechanism for this transformation by ttIL-12 treatment was induction of expression of CXCL9 and reduction of expression of CXCL2 and CCL22 in tumors.

CONCLUSIONS

ttIL-12 when combined with surgery led to conversion to the IFNγHiCD8HiFOXP3LowCD33Low immune profile, eliminated relapse and metastasis, and prolonged overall survival.

Using immunotherapy to boost the abscopal effect

More than 60 years ago, the effect whereby radiotherapy at one site may lead to regression of metastatic cancer at distant sites that are not irradiated was described and called the abscopal effect (from 'ab scopus', that is, away from the target). The abscopal effect has been connected to mechanisms involving the immune system. However, the effect is rare because at the time of treatment, established immune-tolerance mechanisms may hamper the development of sufficiently robust abscopal responses. Today, the growing consensus is that combining radiotherapy with immunotherapy provides an opportunity to boost abscopal response rates, extending the use of radiotherapy to treatment of both local and metastatic disease. In this Opinion article, we review evidence for this growing consensus and highlight emerging limitations to boosting the abscopal effect using immunotherapy. This is followed by a perspective on current and potential cross-disciplinary approaches, including the use of smart materials to address these limitations.

[PD-L1 expression and PD-1/PD-L1 inhibitors in breast cancer]

The development of immune checkpoints inhibitors represents one of the major recent advances in oncology. Monoclonal antibodies directed against the programmed cell death protein 1 (PD-1) or its ligand (PD-L1) provides durable disease control, particularly in melanoma, lung, kidney, bladder and head and neck cancers. The purpose of this review is to synthesize current data on the expression of PD-L1 in breast cancer and on the preliminary clinical results of PD-1/PD-L1 inhibitors in breast cancer patients. In breast cancer, PD-L1 expression is heterogeneous and is generally associated with the presence of tumor-infiltrating lymphocytes as well as the presence of poor-prognosis factors, such as young age, high grade, ER-negativity, PR-negativity, and HER-2 overexpression, high proliferative index, and aggressive molecular subtypes (triple negative, basal-like, HER-2-overexpressing). Its prognostic value remains controversial when assessed with immunohistochemistry, whereas it seems favorable in triple-negative cancers when assessed at the mRNA level. Early clinical trials with PD-1/PD-L1 inhibitors in breast cancer have shown efficacy in terms of tumor response and/or disease control in refractory metastatic breast cancers, notably in the triple-negative subtype. Many trials are currently underway, both in the metastatic and neo-adjuvant setting. A crucial issue is identification of biomarkers predictive of response to PD-1/PD-L1 inhibitors.

Immunotherapy in Breast Cancer: the Emerging Role of PD-1 and PD-L1

PURPOSE OF REVIEW

The purpose of the review is to summarize the data regarding PD-L1 expression in breast cancer and the results of first clinical trials with PD-1 or PD-L1 inhibitors in patients with metastatic breast cancer.

RECENT FINDINGS

PD-L1 expression is heterogeneous across primary breast cancers, and is generally associated with the presence of tumor-infiltrating lymphocytes and the presence of poor-prognosis features such as high grade, and aggressive molecular subtypes (triple-negative (TN), basal, HER2-enriched). Early phase clinical trials using PD-1 or PD-L1 inhibitors alone or in combination have shown objective tumor responses and durable long-term disease control, in heavily pre-treated patients, notably in the TN subtype. Blockade of PD-1 or PD-L1 shows impressive antitumor activity in some subsets of breast cancer patients. Many clinical trials are ongoing in the metastatic and neoadjuvant setting, alone and in combination with chemotherapy, targeted therapy, radiotherapy, and/or other immune therapy. The identification of biomarkers predictive for a clinical benefit is warranted.

Prognostic significance of IgG4+ plasma cell infiltrates following neoadjuvant chemoradiation therapy for esophageal adenocarcinoma

Lymphoplasmacytic infiltrates in esophageal adenocarcinoma (EAC) tissue following chemoradiotherapy (CRT) reflect alterations in the tumor immunoenvironment. The presence and role of plasma cells in this process are poorly understood. Our aim was to characterize the IgG4+ plasma cell population in EAC following CRT. Seventy-one esophagectomy specimens post-CRT were compared with a surgery-only group of 31 EACs. The distribution, density, and ratio of IgG4+ and IgG+ plasma cells were evaluated by immunohistochemistry and correlated with clinicopathologic features, treatment response, and survival. In the CRT group, the presence of higher numbers of IgG4+ (≥ median of 94/high-power field) and IgG+ (≥ median of 225/high-power field) plasma cells and increased IgG4+/IgG+ ratio (≥ median of 41%) within ulcers was associated with complete or near-complete treatment response (P = .0077, P = .0503, and P = .0063, respectively). Lower tumor grade, smaller tumor size, and higher levels of IgG4+ plasma cells in posttherapy ulcers significantly correlated with better overall survival, whereas pretherapy clinical stage, posttherapy pathologic stage, smaller tumor size, and lower tumor grade were associated with longer recurrence-free survival. Multivariate analysis revealed that both posttherapy pathologic stage and high IgG4+ plasma cells in ulcers were independent predictors of overall survival (P = .05 and P = .01), whereas only posttherapy pathologic stage was associated with recurrence-free survival (P < .01). This is the first study describing a dense IgG4+ plasma cell infiltrate in EAC following CRT. The presence of increased IgG4+ plasma cells may be a novel reliable factor to predict prognosis of EAC patients following CRT.

Adenosine can thwart antitumor immune responses elicited by radiotherapy : Therapeutic strategies alleviating protumor ADO activities

BACKGROUND

By studying the bioenergetic status we could show that the development of tumor hypoxia is accompanied, apart from myriad other biologically relevant effects, by a substantial accumulation of adenosine (ADO). ADO has been shown to act as a strong immunosuppressive agent in tumors by modulating the innate and adaptive immune system. In contrast to ADO, standard radiotherapy (RT) can either stimulate or abrogate antitumor immune responses. Herein, we present ADO-mediated mechanisms that may thwart antitumor immune responses elicited by RT.

MATERIALS AND METHODS

An overview of the generation, accumulation, and ADO-related multifaceted inhibition of immune functions, contrasted with the antitumor immune effects of RT, is provided.

RESULTS

Upon hypoxic stress, cancer cells release ATP into the extracellular space where nucleotides are converted into ADO by hypoxia-sensitive, membrane-bound ectoenzymes (CD39/CD73). ADO actions are mediated upon binding to surface receptors, mainly A2A receptors on tumor and immune cells. Receptor activation leads to a broad spectrum of strong immunosuppressive properties facilitating tumor escape from immune control. Mechanisms include (1) impaired activity of CD4 (+) T and CD8 (+) T, NK cells and dendritic cells (DC), decreased production of immuno-stimulatory lymphokines, and (2) activation of Treg cells, expansion of MDSCs, promotion of M2 macrophages, and increased activity of major immunosuppressive cytokines. In addition, ADO can directly stimulate tumor proliferation and angiogenesis.

CONCLUSION

ADO mechanisms described can thwart antitumor immune responses elicited by RT. Therapeutic strategies alleviating tumor-promoting activities of ADO include respiratory hyperoxia or mild hyperthermia, inhibition of CD39/CD73 ectoenzymes or blockade of A2A receptors, and inhibition of ATP-release channels or ADO transporters.

Immunogenic versus tolerogenic phagocytosis during anticancer therapy: mechanisms and clinical translation

Phagocytosis of dying cells is a major homeostatic process that represents the final stage of cell death in a tissue context. Under basal conditions, in a diseased tissue (such as cancer) or after treatment with cytotoxic therapies (such as anticancer therapies), phagocytosis has a major role in avoiding toxic accumulation of cellular corpses. Recognition and phagocytosis of dying cancer cells dictate the eventual immunological consequences (i.e., tolerogenic, inflammatory or immunogenic) depending on a series of factors, including the type of 'eat me' signals. Homeostatic clearance of dying cancer cells (i.e., tolerogenic phagocytosis) tends to facilitate pro-tumorigenic processes and actively suppress antitumour immunity. Conversely, cancer cells killed by immunogenic anticancer therapies may stimulate non-homeostatic clearance by antigen-presenting cells and drive cancer antigen-directed immunity. On the other hand, (a general) inflammatory clearance of dying cancer cells could have pro-tumorigenic or antitumorigenic consequences depending on the context. Interestingly, the immunosuppressive consequences that accompany tolerogenic phagocytosis can be reversed through immune-checkpoint therapies. In the present review, we discuss the pivotal role of phagocytosis in regulating responses to anticancer therapy. We give particular attention to the role of phagocytosis following treatment with immunogenic or immune-checkpoint therapies, the clinical prognostic and predictive significance of phagocytic signals for cancer patients and the therapeutic strategies that can be employed for direct targeting of phagocytic determinants.

Immunotherapeutic approaches in prostate cancer: combinations and clinical integration

Despite multiple immunologic approaches with peptide, protein, and DNA vaccines, no single therapy has induced complete remission or maintained durability of response in patients with castration-resistant prostate cancer (CRPC). Historically, immunotherapy has had limited effect on solid tumors with the exception of melanoma and renal cell carcinomas, which have been deemed as immunologic cancers given their potential for remissions either spontaneously or after removal of the primary lesion. There is considerable excitement about using an immunotherapy in combination with biologic agents such as checkpoint inhibitors, cytokines, other vaccines, or chemotherapy. Sipuleucel-T represents one of several novel immunologic therapeutic approaches to treat prostate cancer in addition to other solid tumors. It is the first in its class of autologous cellular therapies to demonstrate safety and an overall survival benefit in patients with asymptomatic or minimally symptomatic CRPC and represents a unique treatment method that may be further enhanced with other agents. Although sipuleucel-T can be used as a foundation on which to build and enhance future immunologic clinical trials, other exciting strategies are in development that may be easily integrated into the algorithm of current care.

Tumor-targeted and immune-targeted monoclonal antibodies: Going from passive to active immunotherapy

Monoclonal antibodies (mAbs) have inaugurated the concepts of tumor-targeted therapy and personalized medicine. A new family of mAbs is currently emerging in the clinic, which target immune cells rather than cancer cells. These immune-targeted therapies have recently demonstrated long-term tumor responses in adults with refractory/relapsing metastatic solid tumors. Pediatric cancers are different from their adult counterparts in terms of histological features and immune infiltrates. However, the same immune checkpoint targets can be expressed within the microenvironment of pediatric tumors. The benefits of immune checkpoint blockade in pediatric cancers are currently under evaluation in early phase clinical trials.

Myeloid Cells as Targets for Therapy in Solid Tumors

It is well established that cancer development ensues based on reciprocal interactions between genomically altered neoplastic cells and diverse populations of recruited "host" cells co-opted to support malignant progression. Among the host cells recruited into tumor microenvironments, several subtypes of myeloid cells, including macrophages, monocytes, dendritic cells, and granulocytes contribute to tumor development by providing tumor-promoting factors as well as a spectrum of molecules that suppress cytotoxic activities of T lymphocytes. Based on compelling preclinical data revealing that inhibition of critical myeloid-based programs leads to tumor suppression, novel immune-based therapies and approaches are now entering the clinic for evaluation. This review discusses mechanisms underlying protumorigenic programming of myeloid cells and discusses how targeting of these has potential to attenuate solid tumor progression via the induction and of mobilization CD8 cytotoxic T cell immunity.

NZ28-induced inhibition of HSF1, SP1 and NF-κB triggers the loss of the natural killer cell-activating ligands MICA/B on human tumor cells

The activity of natural killer (NK) cells is regulated by activating and inhibiting receptors, whereby the C-type lectin natural killer group 2D (NKG2D) receptor serves as the major activating receptor on NK cells which recognizes major histocompatibility class I chain-related proteins A and B (MICA/B). The MICA/B expression has been described to be regulated by the transcription factor heat shock factor 1 (HSF1). Inhibition of heat shock protein 90 (Hsp90) is known to induce the heat shock response via activation of HSF1 which is associated with tumor development, metastasis and therapy resistance and also with an increased susceptibility to NK cell-mediated lysis. Therefore, we compared the effects of Hsp90 inhibitor NVP-AUY922, HSF1 inhibitor NZ28 and HSF1 knockdown on the sensitivity of lung (H1339) and breast (MDA-MB-231, T47D) cancer cells to NK cell-mediated cytotoxicity and the expression of the NKG2D ligands MICA/B. Although NVP-AUY922 activates HSF1, neither the MICA/B surface density on tumor cells nor their susceptibility to NK cell-mediated lysis was affected. A single knockdown of HSF1 by shRNA decreased the surface expression of MICB but not that of MICA, and thereby, the NK cell-mediated lysis was only partially blocked. In contrast, NZ28 completely blocked the MICA/B membrane expression on tumor cells and thereby strongly inhibited the NK cell-mediated cytotoxicity. This effect might be explained by a simultaneous inhibition of the transcription factors HSF1, Sp1 and NF-κB by NZ28. These findings suggest that new anticancer therapeutics should be investigated with respect to their effects on the innate immune system.

The PERKs of damage-associated molecular patterns mediating cancer immunogenicity: From sensor to the plasma membrane and beyond

Endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) are emerging as key adaptation mechanisms in response to loss of proteostasis, with major cell autonomous and non-autonomous functions impacting cancer progression and therapeutic responses. In recent years, vital physiological roles of the ER in maintenance of proteostasis, Ca(2+) signaling and trafficking through the secretory pathway have emerged. Some of these functions have been shown to be decisive for mobilizing certain signals from injured/dying cancer cells in response to certain anticancer treatments, toward the plasma membrane and ultimately emit them into the extracellular environment, where they may act as danger signals. The spatiotemporally defined emission of these signals, better known as damage-associated molecular patterns (DAMPs), distinguishes this type of cancer cell death from physiological apoptosis, which is tolerogenic in nature, thereby enabling these dying cancer cells to alert the immune system and "re-activate" antitumor immunity. The emission of DAMPs, decisive for immunogenic cell death (ICD) and which include the ER chaperone calreticulin and ATP, is reliant on a danger signaling module induced by certain assorted anticancer treatments through oxidative-ER stress. The main focus of this review is to discuss the emerging role of ER-stress regulated pathways and processes in danger signaling thereby regulating the cancer cell-immune cell interface by the extracellular emission of DAMPs. In particular, we discuss signaling contexts existing upstream and around PERK, a major ER-stress sensor in ICD context, which have not been emphatically discussed in the context of antitumor immunity and ICD up until now. Finally, we briefly discuss the pros and cons of targeting PERK in the context of ICD.

TAT-RasGAP317-326-mediated tumor cell death sensitization can occur independently of Bax and Bak

The increase of cancer specificity and efficacy of anti-tumoral agents are prime strategies to overcome the deleterious side effects associated with anti-cancer treatments. We described earlier a cell-permeable protease-resistant peptide derived from the p120 RasGAP protein, called TAT-RasGAP317-326, as being an efficient tumor-specific sensitizer to apoptosis induced by genotoxins in vitro and in vivo. Bcl-2 family members regulate the intrinsic apoptotic response and as such could be targeted by TAT-RasGAP317-326. Our results indicate that the RasGAP-derived peptide increases cisplatin-induced Bax activation. We found no evidence, using in particular knock-out cells, of an involvement of other Bcl-2 family proteins in the tumor-specific sensitization activity of TAT-RasGAP317-326. The absence of Bax and Bak in mouse embryonic fibroblasts rendered them resistant to cisplatin-induced apoptosis and consequently to the sensitizing action of the RasGAP-derived peptide. Surprisingly, in the HCT116 colon carcinoma cell line, the absence of Bax and Bak did not prevent cisplatin-induced apoptosis and the ability of TAT-RasGAP317-326 to augment this response. Our study also revealed that p53, while required for an efficient genotoxin-induced apoptotic response, is dispensable for the ability of the RasGAP-derived peptide to improve the capacity of genotoxins to decrease long-term survival of cancer cells. Hence, even though genotoxin-induced Bax activity can be increased by TAT-RasGAP317-326, the sensitizing activity of the RasGAP-derived peptide can operate in the absence of a functional mitochondrial intrinsic death pathway.

Therapeutic efficacy of the F8-IL2 immunocytokine in a metastatic mouse model of lung adenocarcinoma

OBJECTIVES

Antibody-cytokine fusion proteins (immunocytokines) represent a novel class of armed antibodies in oncology. In particular, IL2- and TNF-based immunocytokines targeting the EDB domain of fibronectin and the A1 domain of tenascin-C have demonstrated promising anti-tumor activity and are currently investigated in Phase I and Phase II clinical trials. To advance the development of immunocytokines for NSCLC, we here report on the therapeutic efficacy of F8-IL2, an immunocytokine directed against the alternatively spliced EDA domain of fibronectin in a fully immunocompetent, orthotopic model of NSCLC, and the characterization of the target antigen expression in human NSCLC specimens.

MATERIALS AND METHODS

We evaluated the therapeutic efficacy of the F8-IL2 immunocytokine utilizing a K-ras mutant, p53 deficient metastatic mouse model of NSCLC derived from the latest generation of genetically engineered and conditional tumor models. In parallel, we assessed the presence of the EDA domain of fibronectin by immunofluorescence in lung biopsies obtained from patients with NSCLC.

RESULTS

The EDA domain of fibronectin was broadly expressed in lung metastases obtained from our model. Treatment with F8-IL2 induced substantial local changes within immune effector cell populations and demonstrated promising therapeutic efficacy as monotherapy. The target of F8-IL2, the EDA domain of fibronectin, was present in all human lung adenocarcinoma specimens tested.

CONCLUSION

Both the therapeutic efficacy in a metastatic mouse model of NSCLC and the extensive presence of the EDA domain of fibronectin in human NSCLC biopsies support the rational development of therapies based on the F8-IL2 immunocytokine for the treatment of NSCLC.

Targeting of prosurvival pathways as therapeutic approaches against primary effusion lymphomas: past, present, and Future

Constitutively activated prosurvival pathways render cancer cells addicted to their effects. Consequently they turn out to be the Achilles' heels whose inhibition can be exploited in anticancer therapy. Primary effusion lymphomas (PELs) are very aggressive non-Hodgkin's B cell lymphomas, whose pathogenesis is strictly linked to Kaposi's sarcoma herpesvirus (KSHV) infection. Here we summarized previous studies from our and other laboratories exploring the cytotoxic effect of drugs inhibiting the main prosurvival pathways activated in PEL cells. Moreover, the immunogenicity of cell death, in terms of dendritic cell (DC) activation and their potential side effect on DCs, is discussed.

Targeting the hallmarks of cancer with therapy-induced endoplasmic reticulum (ER) stress

The endoplasmic reticulum (ER) is at the center of a number of vital cellular processes such as cell growth, death, and differentiation, crosstalk with immune or stromal cells, and maintenance of proteostasis or homeostasis, and ER functions have implications for various pathologies including cancer. Recently, a number of major hallmarks of cancer have been delineated that are expected to facilitate the development of anticancer therapies. However, therapeutic induction of ER stress as a strategy to broadly target multiple hallmarks of cancer has been seldom discussed despite the fact that several primary or secondary ER stress-inducing therapies have been found to exhibit positive clinical activity in cancer patients. In the present review we provide a brief historical overview of the major discoveries and milestones in the field of ER stress biology with important implications for anticancer therapy. Furthermore, we comprehensively discuss possible strategies enabling the targeting of multiple hallmarks of cancer with therapy-induced ER stress.

Activation of dendritic cells by tumor cell death

A growing number of studies indicate that cell death can be either immunogenic or not, depending on its modalities, the type and the activation state of the cells, and finally, the environment where it happens. Increased understanding of the immunogenicity of cancer cell death will significantly improve the outcome of chemotherapeutic treatments.

Primary sterile necrotic cells fail to cross-prime CD8(+) T cells

Necrotic cells are known to activate the innate immune system and trigger inflammation by releasing damage associated molecular patterns (DAMPs). However, how necrotic cells influence the induction of antigen-specific CD8(+) T cell-mediated adaptive immune responses under sterile conditions, in the absence of pathogen associated molecular patterns (PAMPs), remains poorly understood. Here, we examined antigen-specific CD8(+) T-cell responses to primary sterile necrotic tumor cells both in vitro and in vivo. We found that primary necrotic cells alone fail to generate CD8(+) T cell-dependent immune responses toward cell-associated antigens. We show that necrotic cells trigger CD8(+) T-cell immunity only in the presence of PAMPs or analogs, such as p(dI-dC) and/or unmethylated CpG DNA. The electroporation of tumor cells with these PAMPs prior to necrosis induction triggered antigen-specific CD8(+) T-cell responses through a TLR9/MyD88-dependent pathway. In addition, we found that necrotic cells contain factors that can block the cross-priming of CD8(+) T cells even under non-sterile conditions and can serve as a possible mechanism of immunosuppression. These results suggest that antigen-specific CD8(+) T-cell responses to primary necrotic tumor cells can be induced in the presence of PAMPs and thus have a substantial impact on the development of antitumor vaccination strategies.

Metastatic castration-resistant prostate cancer: new therapies, novel combination strategies and implications for immunotherapy

For the past decade, docetaxel has remained the global standard of care for frontline treatment of metastatic castration-resistant prostate cancer (mCRPC). Until recently, there were limited options for patients with mCRPC following docetaxel failure or resistance, but now the approved treatment choices for these patients have expanded to include abiraterone acetate, cabazitaxel and enzalutamide. Additionally, the radioactive therapeutic agent radium-223 dichloride has been recently approved in patients with CRPC with bone metastases. Although each of these agents has been shown to convey significant survival benefit as a monotherapy, preclinical findings suggest that combining such innovative strategies with traditional treatments may achieve additive or synergistic effects, further augmenting patient benefit. This review will discuss the transformation of the post-docetaxel space in mCRPC, highlighting the spectrum of newly approved agents in this setting in the USA and the European Union, as well as summarizing treatments with non-chemotherapeutic mechanisms of action that have demonstrated promising results in recent phase 3 trials. Lastly, this review will address the potential of combinatorial regimens in mCRPC, including the pairing of novel immunotherapeutic approaches with chemotherapy, radiotherapy or androgen ablation.

The key role of calreticulin in immunomodulation induced by chemotherapeutic agents

BACKGROUND

It has recently been shown that certain chemotherapeutic agents can improve host immune responses. The present study aimed to demonstrate the mechanism by which chemotherapeutic agents modify the tumor microenvironment and induce tumor-specific immune responses.

METHODS

Three mouse cancer cell lines [CT26 mouse colon cancer cells, B16 melanoma cells and Lewis lung carcinoma (LLC)], 5 human carcinoma cell lines (human esophageal squamous cell carcinoma cell lines TE8 and HEC46 and the human pancreatic carcinoma cell lines PK-9, AsPC-1 and SUIT-2) and 5 chemotherapeutic agents [mitoxantrone (MIT), mitomycin C(MMC), 5-fluorouracil (5FU), camptothecin (CPT-11) and cisplatin (CDDP)] that are frequently used in a clinical setting for cancer treatment were utilized to investigate the surface expression level of calreticulin and HLA class I after exposure to chemotherapeutic agents.

RESULTS

Increased calreticulin (CRT) expression on the surface of mouse cell lines and, moreover, increased surface expression levels of both CRT and HLA class I in all human cell lines were observed in cells treated by the chemotherapeutic agents as compared with non-treated cells. The surface expression level of CRT was significantly correlated with the HLA class I expression level in all human cell lines.

CONCLUSIONS

In conclusion, chemotherapeutic drugs can improve the immunogenicity of cancer cells in a cell-specific manner through the mechanism of translocation of CRT.

Current status of interleukin-10 and regulatory T-cells in cancer

PURPOSE OF REVIEW

Tumor growth elicits antigen-specific cytotoxic as well as immune suppressive responses. Interleukin-10 (IL-10) is a key immune-suppressive cytokine produced by regulatory T-cells and by helper T-cells. Here, we review pleiotropic functions of IL-10 that impact the immune pathology of cancer.

RECENT FINDINGS

The role of IL-10 in cancer has become less certain with the knowledge of its immune stimulatory functions. IL-10 is needed for T-helper cell functions, T-cell immune surveillance, and suppression of cancer-associated inflammation. By promoting tumor-specific immune surveillance and hindering pathogenic inflammation, IL-10 is emerging as a key cytokine in the battle of the host against cancer.

SUMMARY

IL-10 functions at the cross-roads of immune stimulation and immune suppression in cancer. Immunological mechanisms of action of IL-10 can be ultimately exploited to develop novel and effective cancer therapies.

Radiation fosters dose-dependent and chemotherapy-induced immunogenic cell death

Established tumors are typified by an immunosuppresive microenvironment. Countering this naturally occurring phenomenon, emerging evidence suggests that radiation promotes a proimmunogenic milieu within the tumor capable of stimulating host cancer-specific immune responses. Three cryptic immunogenic components of cytotoxic-agent induced cell death—namely, calreticulin cell surface exposure, the release of high mobility group box 1 (HMGB1) protein, and the liberation of ATP—have been previously shown to be critical for dendritic cell (DC) activation and effector T-cell priming. Thus, these immune-mobilizing components commonly presage tumor rejection in response to treatment. We initially set out to address the hypothesis that radiation-induced immunogenic cell death (ICD) is dose-dependent. Next, we hypothesized that radiation would enhance chemotherapy-induced ICD when given concomitantly, as suggested by the favorable clinical outcomes observed in response to analogous concurrent chemoradiation regimens. Thus, we designed an in vitro assay to examine the 3 hallmark features of ICD at clinically relevant doses of radiation. We then tested the immunogenic-death inducing effects of radiation combined with carboplatin or paclitaxel, focusing on these combinations to mimic chemoradiation regimens actually used in clinical trials of early stage triple negative [NCT0128953/NYU-10–01969] and locally advanced [NYU-06209] breast cancer patients, respectively. Despite the obvious limitations of an in vitro model, radiotherapy produced both a dose-dependent induction and chemotherapeutic enhancement of ICD. These findings provide preliminary evidence that ICD stimulated by either high-dose radiotherapy alone, or concurrent chemoradiation regimens, may contribute to the establishment of a peritumoral proimmunogenic milieu.

Mast cells as targets for immunotherapy of solid tumors

Mast cells have historically been studied mainly in the context of allergic disease. In recent years, we have come to understand the critical importance of mast cells in tissue remodeling events and their role as sentinel cells in the induction and development of effective immune responses to infection. Studies of the role of mast cells in tumor immunity are more limited. The pro-tumorigenic role of mast cells has been widely reported. However, mast cell infiltration predicts improved prognosis in some cancers, suggesting that their prognostic value may be dependent on other variables. Such factors may include the nature of local mast cell subsets and the various activation stimuli present within the tumor microenvironment. Experimental models have highlighted the importance of mast cells in orchestrating the anti-tumor events that follow immunotherapies that target innate immunity. Mast cells are long-lived tissue resident cells that are abundant around many solid tumors and are radiation resistant making them unique candidates for combined treatment modalities. This review will examine some of the key roles of mast cells in tumor immunity, with a focus on potential immunotherapeutic interventions that harness the sentinel role of mast cells.

The impact of radiation therapy on the antitumor immunity: local effects and systemic consequences

The main antitumor efficacy of irradiation relies in its direct cytotoxic effect. Increasing evidence indicates a systemic effect of radiation though, mediated mainly by the immune system. In this review we wish to focus on the radiotherapy induced modifications of the soluble and cellular mediators of the antitumor immune response and summarize some of the mechanisms by which radiation driven local and systemic bystander effects can influence tumor immunogenicity. In different tumor types due to the intrinsic immunogenicity of the tumor cells and the immunological characteristics of the tumor microenvironment, different radiation induced immune modulatory mechanisms are predominant. Radiation most probably can only amplify or augment a pro-immunogenic phenotype and can hardly change by itself a net immune suppressing environment into an immune stimulating one. This immune modulatory potential of radiotherapy could be exploited in tumor treatment by developing combined radiotherapeutic and immunotherapeutic approaches. The last few years showed a dramatic increase in the knowledge of radiation induced out-of field and systemic effects, which foresees a rapid progress in the development and clinical application of these new, combined therapies for cancer cure.

Update on the challenges and recent advances in cancer immunotherapy

This overview provides an analysis of some of the immunotherapies currently in use and under investigation, with a special focus on the tumor microenvironment, which we believe is a major factor responsible for the general failure of immunotherapy to date. It is our expectation that combining immunotherapy with methods of altering the tumor microenvironment and targeting regulatory T cells and myeloid cells will yield favorable results.