The tipping point for combination therapy: cancer vaccines with radiation, chemotherapy, or targeted small molecule inhibitors

Case report: Interstitial implantation radiotherapy combined with immunotherapy and GM-CSF in oligometastatic platinum-resistant ovarian cancer

Background

Treatment for platinum-resistant ovarian cancer is challenging. Currently, platinum-resistant ovarian cancer is typically treated with non-platinum single-agent chemotherapy ± bevacizumab, but the prognosis is often extremely poor. In the treatment of platinum-resistant ovarian cancer patients, reports of triple therapy with interstitial implantation radiotherapy combined with immunotherapy and granulocyte-macrophage colony-stimulating factor (GM-CSF) (PRaG for short) are relatively rare.

Case description

Here, we report a patient with oligometastatic platinum-resistant ovarian cancer. The patient achieved partial response (PR) of the lesion and sustained benefit for more than six months after receiving interstitial implantation radiotherapy combined with immunotherapy along with GM-CSF.

Conclusion

This triple therapy may provide additional options for these patients.

Cancer Vaccines in the Immunotherapy Era: Promise and Potential

Therapeutic vaccines are a promising alternative for active immunotherapy for different types of cancers. Therapeutic cancer vaccines aim to prevent immune system responses that are not targeted at the tumors only, but also boost the anti-tumor immunity and promote regression or eradication of the malignancy without, or with minimal, adverse events. Clinical trial data have pushed the development of cancer vaccines forward, and the US Food and Drug Administration authorized the first therapeutic cancer vaccine. In the present review, we discuss the various types of cancer vaccines and different approaches for the development of therapeutic cancer vaccines, along with the current state of knowledge and future prospects. We also discuss how tumor-induced immune suppression limits the effectiveness of therapeutic vaccinations, and strategies to overcome this barrier to design efficacious, long-lasting anti-tumor immune responses in the generation of vaccines.

Combined radiotherapy and immune checkpoint inhibition for the treatment of advanced hepatocellular carcinoma

Hepatocellular Carcinoma (HCC) is one of the most common cancers and a leading cause of cancer related death worldwide. Until recently, systemic therapy for advanced HCC, defined as Barcelona Clinic Liver Cancer (BCLC) stage B or C, was limited and ineffective in terms of long-term survival. However, over the past decade, immune check point inhibitors (ICI) combinations have emerged as a potential therapeutic option for patients with nonresectable disease. ICI modulate the tumor microenvironment to prevent progression of the tumor. Radiotherapy is a crucial tool in treating unresectable HCC and may enhance the efficacy of ICI by manipulating the tumor microenvironment and decreasing tumor resistance to certain therapies. We herein review developments in the field of ICI combined with radiotherapy for the treatment of HCC, as well as look at challenges associated with these treatment modalities, and review future directions of combination therapy.

Vaccines in Breast Cancer: Challenges and Breakthroughs

Breast cancer is a problem for women's health globally. Early detection techniques come in a variety of forms ranging from local to systemic and from non-invasive to invasive. The treatment of cancer has always been challenging despite the availability of a wide range of therapeutics. This is either due to the variable behaviour and heterogeneity of the proliferating cells and/or the individual's response towards the treatment applied. However, advancements in cancer biology and scientific technology have changed the course of the cancer treatment approach. This current review briefly encompasses the diagnostics, the latest and most recent breakthrough strategies and challenges, and the limitations in fighting breast cancer, emphasising the development of breast cancer vaccines. It also includes the filed/granted patents referring to the same aspects.

Current Status and Challenges of Vaccination Therapy for Glioblastoma

Glioblastoma (GBM), also known as grade IV astrocytoma, is the most common and deadly type of central nervous system malignancy in adults. Despite significant breakthroughs in current GBM treatments such as surgery, radiotherapy, and chemotherapy, the prognosis for late-stage glioblastoma remains bleak due to tumor recurrence following surgical resection. The poor prognosis highlights the evident and pressing need for more efficient and targeted treatment. Vaccination has successfully treated patients with advanced colorectal and lung cancer. Therefore, the potential value of using tumor vaccines in treating glioblastoma is increasingly discussed as a monotherapy or in combination with other cellular immunotherapies. Cancer vaccination includes both passive administration of monoclonal antibodies and active vaccination procedures to activate, boost, or bias antitumor immunity against cancer cells. This article focuses on active immunotherapy with peptide, genetic (DNA, mRNA), and cell-based vaccines in treating GBM and reviews the various treatment approaches currently being tested. Although the ease of synthesis, relative safety, and ability to elicit tumor-specific immune responses have made these vaccines an invaluable tool for cancer treatment, more extensive cohort studies and better guidelines are needed to improve the efficacy of these vaccines in anti-GBM therapy.

Sustained release of tumor cell lysate and CpG from an injectable, cytotoxic hydrogel for melanoma immunotherapy

Many basic research studies have shown the potential of autologous cancer vaccines in the treatment of melanoma. However, some clinical trials showed that simplex whole tumor cell vaccines can only elicit weak CD8⁺ T cell-mediated antitumor responses which were not enough for effective tumor elimination. So efficient cancer vaccine delivery strategies with improved immunogenicity are needed. Herein, we described a novel hybrid vaccine "MCL" (Melittin-RADA₃₂-CpG-Lysate) which was composed of melittin, RADA₃₂, CpG and tumor lysate. In this hybrid vaccine, antitumor peptide melittin and self-assembling fusion peptide RADA₃₂ were assembled to form the hydrogel framework melittin-RADA₃₂(MR). Then, whole tumor cell lysate and immune adjuvant CpG-ODN were loaded into MR to develop an injectable and cytotoxic hydrogel MCL. MCL showed excellent ability for sustained drug release, to activate dendritic cells and directly kill melanoma cells in vitro. In vivo, MCL not only exerted direct antitumor activity, but also had robust immune initiation effects including the activation of dendritic cells in draining lymph nodes and the infiltration of cytotoxic T lymphocytes (CTLs) in tumor microenvironment. In addition, MCL can efficiently inhibit melanoma growth in B16-F10 tumor bearing mice, which suggested that MCL is a potential cancer vaccine strategy for melanoma treatment.

Local Liver Irradiation Concurrently Versus Sequentially with Cabozantinib on the Pharmacokinetics and Biodistribution in Rats

The aim of this study was to evaluate the radiotherapy (RT)-pharmacokinetics (PK) effect of cabozantinib in concurrent or sequential regimens with external beam radiotherapy (EBRT) or stereotactic body radiation therapy (SBRT). Concurrent and sequential regimens involving RT and cabozantinib were designed. The RT–drug interactions of cabozantinib under RT were confirmed in a free-moving rat model. The drugs were separated on an Agilent ZORBAX SB-phenyl column with a mobile phase consisting of 10 mM potassium dihydrogen phosphate (KH2PO4)–methanol solution (27:73, v/v) for cabozantinib. There were no statistically significant differences in the concentration versus time curve of cabozantinib (AUCcabozantinib) between the control group and the RT2Gy×3 f’x and RT9Gy×3 f’x groups in the concurrent and the sequential regimens. However, compared to those in the control group, the Tmax, T1/2 and MRT decreased by 72.8% (p = 0.04), 49.0% (p = 0.04) and 48.5% (p = 0.04) with RT2Gy×3 f’x in the concurrent regimen, respectively. Additionally, the T1/2 and MRT decreased by 58.8% (p = 0.01) and 57.8% (p = 0.01) in the concurrent RT9Gy×3 f’x group when compared with the control group, respectively. The biodistribution of cabozantinib in the heart increased by 271.4% (p = 0.04) and 120.0% (p = 0.04) with RT2Gy×3 f’x in the concurrent and sequential regimens compared to the concurrent regimen, respectively. Additionally, the biodistribution of cabozantinib in the heart increased by 107.1% (p = 0.01) with the RT9Gy×3 f’x sequential regimen. Compared to the RT9Gy×3 f’x concurrent regimen, the RT9Gy×3 f’x sequential regimen increased the biodistribution of cabozantinib in the heart (81.3%, p = 0.02), liver (110.5%, p = 0.02), lung (125%, p = 0.004) and kidneys (87.5%, p = 0.048). No cabozantinib was detected in the brain in any of the groups. The AUC of cabozantinib is not modulated by irradiation and is not affected by treatment strategies. However, the biodistribution of cabozantinib in the heart is modulated by off-target irradiation and SBRT doses simultaneously. The impact of the biodistribution of cabozantinib with RT9Gy×3 f’x is more significant with the sequential regimen than with the concurrent regimen.

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.

Exploiting the immunogenic potential of standard of care radiation or cisplatin therapy in preclinical models of HPV-associated malignancies

BACKGROUND

While radiation and chemotherapy are primarily purposed for their cytotoxic effects, a growing body of preclinical and clinical evidence demonstrates an immunogenic potential for these standard therapies. Accordingly, we sought to characterize the immunogenic potential of radiation and cisplatin in human tumor models of HPV-associated malignancies. These studies may inform rational combination immuno-oncology (IO) strategies to be employed in the clinic on the backbone of standard of care, and in so doing exploit the immunogenic potential of standard of care to improve durable responses in HPV-associated malignancies.

METHODS

Retroviral transduction with HPV16 E7 established a novel HPV-associated sinonasal squamous cell carcinoma (SNSCC) cell line. Three established HPV16-positive cell lines were also studied (cervical carcinoma and head and neck squamous cell carcinoma). Following determination of sensitivities to standard therapies using MTT assays, flow cytometry was used to characterize induction of immunogenic cell stress following sublethal exposure to radiation or cisplatin, and the functional consequence of this induction was determined using impedance-based real time cell analysis cytotoxicity assays employing HPV16 E7-specific cytotoxic lymphocytes (CTLs) with or without N803 (IL-15/IL-15-Rα superagonist) or exogenous death receptor ligands. In vitro observations were translated using an in vivo xenograft NSG mouse model of human cervical carcinoma evaluating cisplatin in combination with CTL adoptive cell transfer.

RESULTS

We showed that subpopulations surviving clinically relevant doses of radiation or cisplatin therapy were more susceptible to CTL-mediated lysis in four of four tumor models of HPV-associated malignancies, serving as a model for HPV therapeutic vaccine or T-cell receptor adoptive cell transfer. This increased killing was further amplified by IL-15 agonism employing N803. We further characterized that radiation or cisplatin induced immunogenic cell stress in three of three cell lines, and consequently demonstrated that upregulated surface expression of Fas and TRAIL-R2 death receptors at least in part mediated enhanced CTL-mediated lysis. In vivo, cisplatin-induced immunogenic cell stress synergistically potentiated CTL-mediated tumor control in a human model of HPV-associated malignancy.

CONCLUSION

Standard of care radiation or cisplatin therapy induced immunogenic cell stress in preclinical models of HPV-associated malignancies, presenting an opportunity poised for exploitation by employing IO strategies in combination with standard of care.

Chemotherapy: A partnership with immunotherapy in non-small cell lung cancer

Chemotherapy (CT) and immunotherapy (IO) act synergically in the treatment of non-small cell lung cancer (NSCLC). However, the molecular basis of such interaction is poorly understood. The aim of this review was to explore the mechanisms of CT to potentiate the immune system and, consequently, the action of IO. The most up-to-date knowledge concerning the interaction of CT and IO in NSCLC was reviewed and a bibliographic search was made in PubMed/Medline database, using the mentioned keywords, with preference given to recently published articles in English. In addition to the direct cytotoxic effect, CT affects the immune system leading indirectly to cell death. The immune response triggered by PD-1 inhibition is enhanced by the cytotoxic immunogenic effects of CT. This potentiation phenomenon occurs due to an increase in effector cells relatively to regulatory cells, inhibition of myeloid derived suppressor cells, increased potential for cross-presentation by dendritic cells after the death of tumor cells or blocking the STAT6 pathway to increase dendritic cell activity. In conclusion, the effects of CT on the immune system work in synergy with the actions of IO, transforming "cold" tumors into "hot" tumors, which are more visible to the immune system.

Pembrolizumab in combination with gemcitabine for patients with HER2-negative advanced breast cancer: GEICAM/2015-04 (PANGEA-Breast) study

BACKGROUND

We evaluated a new chemoimmunotherapy combination based on the anti-PD1 monoclonal antibody pembrolizumab and the pyrimidine antimetabolite gemcitabine in HER2- advanced breast cancer (ABC) patients previously treated in the advanced setting, in order to explore a potential synergism that could eventually obtain long term benefit in these patients.

METHODS

HER2-negative ABC patients received 21-day cycles of pembrolizumab 200 mg (day 1) and gemcitabine (days 1 and 8). A run-in-phase (6 + 6 design) was planned with two dose levels (DL) of gemcitabine (1,250 mg/m² [DL0]; 1,000 mg/m² [DL1]) to determine the recommended phase II dose (RP2D). The primary objective was objective response rate (ORR). Tumor infiltrating lymphocytes (TILs) density and PD-L1 expression in tumors and myeloid-derived suppressor cells (MDSCs) levels in peripheral blood were analyzed.

RESULTS

Fourteen patients were treated with DL0, resulting in RP2D. Thirty-six patients were evaluated during the first stage of Simon's design. Recruitment was stopped as statistical assumptions were not met. The median age was 52; 21 (58%) patients had triple-negative disease, 28 (78%) visceral involvement, and 27 (75%) ≥ 2 metastatic locations. Progression disease was observed in 29 patients. ORR was 15% (95% CI, 5-32). Eight patients were treated ≥ 6 months before progression. Fourteen patients reported grade ≥ 3 treatment-related adverse events. Due to the small sample size, we did not find any clear association between immune tumor biomarkers and treatment efficacy that could identify a subgroup with higher probability of response or better survival. However, patients that experienced a clinical benefit showed decreased MDSCs levels in peripheral blood along the treatment.

CONCLUSION

Pembrolizumab 200 mg and gemcitabine 1,250 mg/m² were considered as RP2D. The objective of ORR was not met; however, 22% patients were on treatment for ≥ 6 months. ABC patients that could benefit of chemoimmunotherapy strategies must be carefully selected by robust and validated biomarkers. In our heavily pretreated population, TILs, PD-L1 expression and MDSCs levels could not identify a subgroup of patients for whom the combination of gemcitabine and pembrolizumab would induce long term benefit.

TRIAL REGISTRATION

ClinicalTrials.gov and EudraCT (NCT03025880 and 2016-001,779-54, respectively). Registration dates: 20/01/2017 and 18/11/2016, respectively.

Immune-awakening Saccharomyces-inspired nanocarrier for oral target delivery to lymph and tumors

Utilization of the intestinal lymphatic pathway will allow extraordinary gains in lymph and tumors cascade-targeted delivery of oral drugs and awakening the innate/adaptive immunity of the body and the lesion microenvironment, in addition to improving oral bioavailability relative to other means of delivery of oral drugs. Here, inspired by the specific invasion route of intestinal microorganisms, we pioneered an immune-awakening Saccharomyces-inspired mesoporous silicon nanoparticle (yMSN) for the ingenious cascade-targeted delivery of therapeutic cancer vaccines and antitumor drugs to lymph and tumors via the intestinal lymphatic pathway. Encouragingly, yMSN high-loaded tumor-specific antigens (OVA, 11.9%) and anti-tumor drugs (Len, 28.6%) with high stability, namely Len/OVA/yMSN, efficiently co-delivered OVA and Len to their desired target sites. Moreover, yMSN concomitantly awakened the innate antitumor immunity of dendritic cells and macrophages, strengthening vaccine-induced adaptive immune responses and reversing macrophage-associated immunosuppression in the tumor microenvironment. Surprisingly, Len/OVA/yMSN treatment resulted in excellent synergistic antitumor efficacy and long-term antitumor memory in OVA-Hepa1-6-bearing mice. This high-performance nanocarrier provides a novel approach for lesion-targeting delivery of oral drugs accompanied with awakening of the innate/adaptive immunity of the lesion environment, and also represents a novel path for the oral delivery of diverse therapeutic agents targeting other lymph-mediated diseases.

Dying of Stress: Chemotherapy, Radiotherapy, and Small-Molecule Inhibitors in Immunogenic Cell Death and Immunogenic Modulation

Innovative strategies to re-establish the immune-mediated destruction of malignant cells is paramount to the success of anti-cancer therapy. Accumulating evidence suggests that radiotherapy and select chemotherapeutic drugs and small molecule inhibitors induce immunogenic cell stress on tumors that results in improved immune recognition and targeting of the malignant cells. Through immunogenic cell death, which entails the release of antigens and danger signals, and immunogenic modulation, wherein the phenotype of stressed cells is altered to become more susceptible to immune attack, radiotherapies, chemotherapies, and small-molecule inhibitors exert immune-mediated anti-tumor responses. In this review, we discuss the mechanisms of immunogenic cell death and immunogenic modulation and their relevance in the anti-tumor activity of radiotherapies, chemotherapies, and small-molecule inhibitors. Our aim is to feature the immunological aspects of conventional and targeted cancer therapies and highlight how these therapies may be compatible with emerging immunotherapy approaches.

Biology, Significance and Immune Signaling of Mucin 1 in Hepatocellular Carcinoma

Mucin 1 (MUC 1) is a highly glycosylated tumor-associated antigen (TAA) overexpressed in hepatocellular carcinoma (HCC). This protein plays a critical role in various immune-mediated signaling pathways at its transcriptional and post-transcriptional levels, leading to immune evasion and metastasis in HCC. HCC cells maintain an immune-suppressive environment with the help of immunesuppressive tumor-associated antigens, resulting in a metastatic spread of the disease. The development of intense immunotherapeutic strategies to target tumor-associated antigen is critical to overcoming the progression of HCC. MUC 1 remains the most recognized tumor-associated antigen since its discovery over 30 years ago. A few promising immunotherapies targeting MUC 1 are currently under clinical trials, including CAR-T and CAR-pNK-mediated therapies. This review highlights the biosynthesis, significance, and clinical implication of MUC 1 as an immune target in HCC.

From Immunogenic Cell Death to Immunogenic Modulation: Select Chemotherapy Regimens Induce a Spectrum of Immune-Enhancing Activities in the Tumor Microenvironment

Cancer treatment has rapidly entered the age of immunotherapy, and it is becoming clear that the effective therapy of established tumors necessitates rational multi-combination immunotherapy strategies. But even in the advent of immunotherapy, the clinical role of standard-of-care chemotherapy regimens still remains significant and may be complementary to emerging immunotherapeutic approaches. Depending on dose, schedule, and agent, chemotherapy can induce immunogenic cell death, resulting in the release of tumor antigens to stimulate an immune response, or immunogenic modulation, sensitizing surviving tumor cells to immune cell killing. While these have been previously defined as distinct processes, in this review we examine the published mechanisms supporting both immunogenic cell death and immunogenic modulation and propose they be reclassified as similar effects termed “immunogenic cell stress.”

Treatment-induced immunogenic cell stress is an important result of cytotoxic chemotherapy and future research should consider immunogenic cell stress as a whole rather than just immunogenic cell death or immunogenic modulation. Cancer treatment strategies should be designed specifically to take advantage of these effects in combination immunotherapy, and novel chemotherapy regimens should be designed and investigated to potentially induce all aspects of immunogenic cell stress.

Exploiting off-target effects of estrogen deprivation to sensitize estrogen receptor negative breast cancer to immune killing

Background

There are highly effective treatment strategies for estrogen receptor (ER)+, progesterone receptor (PR)+, and HER2+ breast cancers; however, there are limited targeted therapeutic strategies for the 10%–15% of women who are diagnosed with triple-negative breast cancer. Here, we hypothesize that ER targeting drugs induce phenotypic changes to sensitize breast tumor cells to immune-mediated killing regardless of their ER status.

Methods

Real-time cell analysis, flow cytometry, qRT-PCR, western blotting, and multiplexed RNA profiling were performed to characterize ER+ and ER− breast cancer cells and to interrogate the phenotypic effects of ER targeting drugs. Sensitization of breast cancer cells to immune cell killing by the tamoxifen metabolite 4-hydroxytamoxifen (4-OHT) and fulvestrant was determined through in vitro health-donor natural killer cell ¹¹¹IN-release killing assays. A syngeneic tumor study was performed to validate these findings in vivo.

Results

Pretreatment with tamoxifen metabolite 4-OHT or fulvestrant resulted in increased natural killer (NK)–mediated cell lysis of both ER+ and ER− breast cancer cells. Through multiplexed RNA profiling analysis of 4-OHT-treated ER+ and ER− cells, we identified increased activation of apoptotic and death receptor signaling pathways and identified G protein-coupled receptor for estrogen (GPR30) engagement as a putative mechanism for immunogenic modulation. Using the specific GPR30 agonist G-1, we demonstrate that targeted activation of GPR30 signaling resulted in increased NK cell killing. Furthermore, we show that knockdown of GPR30 inhibited 4-OHT and fulvestrant mediated increases to NK cell killing, demonstrating this is dependent on GPR30 expression. Moreover, we demonstrate that this mechanism remains active in a 4-OHT-resistant MCF7 cell line, showing that even in patient populations with ER+ tumors that are resistant to the cytotoxic effects of tamoxifen, 4-OHT treatment sensitizes them to immune-mediated killing. Moreover, we find that fulvestrant pretreatment of tumor cells synergizes with the IL-15 superagonist N-803 treatment of NK cells and sensitizes tumor cells to killing by programmed death-ligand 1 (PD-L1) targeting high-affinity natural killer (t-haNK) cells. Finally, we demonstrate that the combination of fulvestrant and N-803 is effective in triple-negative breast cancer in vivo.

Conclusion

Together, these findings demonstrate a novel effect of ER targeting drugs on the interaction of ER+ and, surprisingly, ER− tumors cells with the immune system. This study is the first to demonstrate the potential use of ER targeting drugs as immunomodulatory agents in an ER agnostic manner and may inform novel immunotherapy strategies in breast cancer.

The construction of a lymphoma cell-based, DC-targeted vaccine, and its application in lymphoma prevention and cure

In recent years, Non-Hodgkin lymphoma (NHL) has been one of the most fast-growing malignant tumor diseases. NHL poses severe damages to physical health and a heavy burden to patients. Traditional therapies (chemotherapy or radiotherapy) bring some benefit to patients, but have severe adverse effects and do not prevent relapse. The relevance of emerging immunotherapy options (immune-checkpoint blockers or adoptive cellular methods) for NHL remains uncertain, and more intensive evaluations are needed. In this work, inspired by the idea of vaccination to promote an immune response to destroy tumors, we used a biomaterial-based strategy to improve a tumor cell-based vaccine and constructed a novel vaccine named Man-EG7/CH@CpG with antitumor properties. In this vaccine, natural tumor cells are used as a vector to load CpG-ODN, and following lethal irradiation, the formulations were decorated with mannose. The study of the characterization of the double-improved vaccine evidenced the enhanced ability of DCs targeting and improved immunocompetence, which displayed an antitumor function. In the lymphoma prevention model, the Man-EG7/CH@CpG vaccine restrained tumor formation with high efficiency. Furthermore, unlike the non-improved vaccine, the double-improved vaccine elicited an enhanced antitumor effect in the lymphoma treatment model. Next, to improve the moderate therapeutic effect of the mono-treatment method, we incorporated a chemotherapeutic drug (doxorubicin, DOX) into the process of vaccination and devised a combination regimen. Fortunately, a tumor inhibition rate of ~85% was achieved via the combination therapy, which could not be achieved by mono-chemotherapy or mono-immunotherapy. In summary, the strategy presented here may provide a novel direction in the establishment of a tumor vaccine and is the basis for a prioritization scheme of immuno-chemotherapy in enhancing the therapeutic effect on NHL.

Immune signature driven by ADT-induced immune microenvironment remodeling in prostate cancer is correlated with recurrence-free survival and immune infiltration

Androgen deprivation therapy (ADT) is a cornerstone treatment for locally advanced or metastatic prostate cancer (PCa). However, its potential effects on the tumor immune microenvironment (TIM) of PCa patients and the underlying mechanism remain largely unclear. To explore the effects of ADT on PCa TIM, RNA sequencing was performed on six paired pre-ADT biopsy and post-ADT PCa lesions, and five paired paracancerous benign tissues from patients receiving neoadjuvant ADT with locally advanced PCa. Bioinformatics methods including ESTIMATE and ssGSEA were used to evaluate the stromal immune score and immune cell infiltration in PCa and paracancerous tissues. Weighted correlation network analysis was used to screen hub genes in the ADT-induced immune remodeling process. The results showed differences exist between PCa and paracancerous tissues in response to ADT. Compared with paracancerous tissues, the immune remodeling effect of ADT in PCa was more intense. ZFP36, JUNB, and SOCS3 served as hub genes in the ADT-induced immune remodeling process and were associated with PSA recurrent-free survival in the TCGA and our neoadjuvant ADT cohort. To investigate the joint action of the above three hub genes, an immune signature score was constructed. The results showed that immune signature score-based immune subtypes reveal the heterogeneity of the immune microenvironment of PCa and showed significant differences in patient prognosis, tumor immune infiltration, mutation burden, and landscape.

Nanoparticle cancer vaccines: Design considerations and recent advances

Vaccines therapeutics manipulate host's immune system and have broad potential for cancer prevention and treatment. However, due to poor immunogenicity and limited safety, fewer cancer vaccines have been successful in clinical trials. Over the past decades, nanotechnology has been exploited to deliver cancer vaccines, eliciting long-lasting and effective immune responses. Compared to traditional vaccines, cancer vaccines delivered by nanomaterials can be tuned towards desired immune profiles by (1) optimizing the physicochemical properties of the nanomaterial carriers, (2) modifying the nanomaterials with targeting molecules, or (3) co-encapsulating with immunostimulators. In order to develop vaccines with desired immunogenicity, a thorough understanding of parameters that affect immune responses is required. Herein, we discussed the effects of physicochemical properties on antigen presentation and immune response, including but not limited to size, particle rigidity, intrinsic immunogenicity. Furthermore, we provided a detailed overview of recent preclinical and clinical advances in nanotechnology for cancer vaccines, and considerations for future directions in advancing the vaccine platform to widespread anti-cancer applications.

Current Status and Future Perspective of Immunotherapy in Gastrointestinal Cancers

Gastrointestinal (GI) cancers represent a major public health problem worldwide. Due to the late detection and high heterogeneity of GI cancers, traditional treatments, including surgery, radiotherapy, chemotherapy, and targeted therapy, have shown limited effects, and the overall prognosis of these patients remains poor. Recently, immunotherapy, involving programmed cell death-1 (PD-1) and its ligand (PD-L1), has shown promising efficacy in several solid cancers and seems to have become a potential treatment option for GI cancers This review focuses on data on the development of immunotherapy-based clinical trials in esophageal cancer, gastric cancer, and colorectal cancer. The predictive biomarkers and combination strategies in clinical trials and translational medicine are also discussed. Finally, prospects for immunotherapy in the treatment of GI cancers are described. Although only a small proportion of patients with GI cancers respond to PD-1/PD-L1 blockade, we strongly believe that precision immunotherapy might improve the overall survival of many more GI cancer patients in the future.

Natural Born Killers: NK Cells in Cancer Therapy

Cellular therapy has emerged as an attractive option for the treatment of cancer, and adoptive transfer of chimeric antigen receptor (CAR) expressing T cells has gained FDA approval in hematologic malignancy. However, limited efficacy was observed using CAR-T therapy in solid tumors. Natural killer (NK) cells are crucial for tumor surveillance and exhibit potent killing capacity of aberrant cells in an antigen-independent manner. Adoptive transfer of unmodified allogeneic or autologous NK cells has shown limited clinical benefit due to factors including low cell number, low cytotoxicity and failure to migrate to tumor sites. To address these problems, immortalized and autologous NK cells have been genetically engineered to express high affinity receptors (CD16), CARs directed against surface proteins (PD-L1, CD19, Her2, etc.) and endogenous cytokines (IL-2 and IL-15) that are crucial for NK cell survival and cytotoxicity, with positive outcomes reported by several groups both preclinically and clinically. With a multitude of NK cell-based therapies currently in clinic trials, it is likely they will play a crucial role in next-generation cell therapy-based treatment. In this review, we will highlight the recent advances and limitations of allogeneic, autologous and genetically enhanced NK cells used in adoptive cell therapy.

Combination of Ipilimumab and Nivolumab in Cancers: From Clinical Practice to Ongoing Clinical Trials

Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) are inhibitory checkpoints that are commonly seen on activated T cells and have been offered as promising targets for the treatment of cancers. Immune checkpoint inhibitors (ICIs)targeting PD-1, including pembrolizumab and nivolumab, and those targeting its ligand PD-L1, including avelumab, atezolizumab, and durvalumab, and two drugs targeting CTLA-4, including ipilimumab and tremelimumab have been approved for the treatment of several cancers and many others are under investigating in advanced trial phases. ICIs increased antitumor T cells’ responses and showed a key role in reducing the acquired immune system tolerance which is overexpressed by cancer and tumor microenvironment. However, 50% of patients could not benefit from ICIs monotherapy. To overcome this, a combination of ipilimumab and nivolumab is frequently investigated as an approach to improve oncological outcomes. Despite promising results for the combination of ipilimumab and nivolumab, safety concerns slowed down the development of such strategies. Herein, we review data concerning the clinical activity and the adverse events of ipilimumab and nivolumab combination therapy, assessing ongoing clinical trials to identify clinical outlines that may support combination therapy as an effective treatment. To the best of our knowledge, this paper is one of the first studies to evaluate the efficacy and safety of ipilimumab and nivolumab combination therapy in several cancers.

Do systemic treatments delivered after Nivolumab result in better outcomes? A bicentric case-control study

BACKGROUND

Immune checkpoint inhibitors (ICI) are now widely used at different stages of non-small cell lung cancers (NSCLC). Some clinical studies suggest that chemotherapy and immunotherapy have synergic activities, raising the question of the best therapeutic sequence. We studied the effect of chemotherapy in advanced NSCLC when administered after immunotherapy by nivolumab.

METHODS

We performed a bicentric, retrospective, case-control study in two French hospitals. Patients with NSCLC treated with chemotherapy after nivolumab between January 2015 and January 2016 were included. Each case was matched on age and number of previous lines to one lung cancer patient who had not received nivolumab. Each CT-scanner has been reviewed and the objective response to chemotherapy was assessed for each patient according to the RECIST 1.1 criteria.

RESULTS

Thirty-one patients with advanced NSCL who had at least received one cycle of chemotherapy after progression under nivolumab in the inclusion period were matched to 31 controls. The median age for cases was 59 yo and the predominant tumoral histology was adenocarcinoma (77%). The progression free survival (PFS) was 2.95 months in the studied group vs 2.69 months (P=0.18) in the control group. At best response, disease control (DC=partial response and stable disease) was better in the case group than in the control group (58% vs 39%, P=0.127). Cases were about five times more likely to get objective response to best evaluation than controls (OR=5.043 [95% CI: 0.975-26.086]; P=0.054). The overall survival (OS) was 7.3 months in the case group and 3.3 months in the control group (P=0.074). Patients who have been treated with targeted therapy instead of chemotherapy and patients with squamous lung cancer had worst PFS and OS.

CONCLUSION

In advanced NSCLC, the chemotherapy progression free survival does not seem higher when administered after nivolumab. However, when administered post-nivolumab, traditional chemotherapy has 5 times more chances to achieve objective response and seems to improve overall survival of cases. Pooled analysis with other similar studies might be interesting for a next step.

Abscopal effect of local irradiation treatment for thymoma: a case report

INTRODUCTION

With the rapid development of immunotherapy in recent years, growing clinical evidence suggests that a combination of radiotherapy and immunotherapy could improve the abscopal response rates and increase survival. However, observations on abscopal effects in patients receiving radiotherapy alone are still very rare. This study reports a rare case of a patient with type B3 thymoma with multiple lung metastases, who received localized irradiation.

CASE PRESENTATION

A 76-year-old Chinese woman was admitted to our hospital in November 2017, and her physical examination revealed a thymus mass with multiple lung metastases. Although the left lower lobe lesion was slightly larger than before, the patient presented with regression of the non-irradiated metastases after treatment with radiotherapy alone.

CONCLUSION

This patient experienced an apparent regression of metastatic mass, suggesting a radiation-induced abscopal effect.

Therapeutic Cancer Vaccination with Ex Vivo RNA-Transfected Dendritic Cells-An Update

Over the last two decades, dendritic cell (DC) vaccination has been studied extensively as active immunotherapy in cancer treatment and has been proven safe in all clinical trials both with respect to short and long-term side effects. For antigen-loading of dendritic cells (DCs) one method is to introduce mRNA coding for the desired antigens. To target the whole antigenic repertoire of a tumor, even the total tumor mRNA of a macrodissected biopsy sample can be used. To date, reports have been published on a total of 781 patients suffering from different tumor entities and HIV-infection, who have been treated with DCs loaded with mRNA. The majority of those were melanoma patients, followed by HIV-infected patients, but leukemias, brain tumors, prostate cancer, renal cell carcinomas, pancreatic cancers and several others have also been treated. Next to antigen-loading, mRNA-electroporation allows a purposeful manipulation of the DCs’ phenotype and function to enhance their immunogenicity. In this review, we intend to give a comprehensive summary of what has been published regarding clinical testing of ex vivo generated mRNA-transfected DCs, with respect to safety and risk/benefit evaluations, choice of tumor antigens and RNA-source, and the design of better DCs for vaccination by transfection of mRNA-encoded functional proteins.

Construction of Nucleus-Targeting Iridium Nanocrystals for Photonic Hyperthermia-Synergized Cancer Radiotherapy

Prominent tumor-cell nucleus targeting of radiosensitizer substantially affects the therapeutic consequence of advanced tumor radiotherapy via lethal nucleus DNA damage. Herein, ultrasmall iridium nanocrystals (Ir NCs, <5 nm) are constructed for efficient tumor-specific photonic hyperthermia-synergized radiotherapy. To endow the NCs with qualified cell nucleus-targeting performance, polyethylene glycol (PEG)-modified Ir NCs are decorated with α_v β₃ integrin-targeting cyclic arginine-glycine-aspartic (c(RGDyC)), designated as RGD, peptides and human immunodeficiency virus-1 transactivator of transcription protein(TAT), respectively, facilitating the tumor-cell-membrane (with overexpressed α_v β₃ integrin) and cell-nucleus targeting. The formulated Ir-RGD-TAT (Ir-R/T) NCs are demonstrated to accumulate inside the nucleus of tumor cells and generate effective DNA lesions upon X-ray irradiation. Further in vivo evaluations verify the satisfactory carcinoma destruction performance against 4T1 tumor xenografts. Importantly, the intriguing photonic NIR adsorption of Ir-R/T NCs has enabled the hyperthermia therapeutics accompanied with photoacoustic imaging modalities, achieving clinically promising biocompatible multifunctional radiosensitized nanoplatforms for effective tumor therapeutics.

Current and emerging avenues for Alzheimer's disease drug targets

Alzheimer's disease (AD), the most frequent cause of dementia, is escalating as a global epidemic, and so far, there is neither cure nor treatment to alter its progression. The most important feature of the disease is neuronal death and loss of cognitive functions, caused probably from several pathological processes in the brain. The main neuropathological features of AD are widely described as amyloid beta (Aβ) plaques and neurofibrillary tangles of the aggregated protein tau, which contribute to the disease. Nevertheless, AD brains suffer from a variety of alterations in function, such as energy metabolism, inflammation and synaptic activity. The latest decades have seen an explosion of genes and molecules that can be employed as targets aiming to improve brain physiology, which can result in preventive strategies for AD. Moreover, therapeutics using these targets can help AD brains to sustain function during the development of AD pathology. Here, we review broadly recent information for potential targets that can modify AD through diverse pharmacological and nonpharmacological approaches including gene therapy. We propose that AD could be tackled not only using combination therapies including Aβ and tau, but also considering insulin and cholesterol metabolism, vascular function, synaptic plasticity, epigenetics, neurovascular junction and blood-brain barrier targets that have been studied recently. We also make a case for the role of gut microbiota in AD. Our hope is to promote the continuing research of diverse targets affecting AD and promote diverse targeting as a near-future strategy.

Immune checkpoint inhibitors for treatment of thymic epithelial tumors: how to maximize benefit and optimize risk?

A greater understanding of anti-tumor immunity has resulted in rapid development of immunotherapy for a wide variety of cancers. Antibodies targeting the immune checkpoints, cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed death-1 (PD-1), or its ligand (PD-L1) have demonstrated clinical activity and are approved for treatment of melanoma, non-small cell lung cancer (NSCLC), renal cell carcinoma, bladder cancer, head and neck cancers, esophageal cancer, hepatocellular carcinoma, and Hodgkin lymphoma, among others. Treatment is generally well tolerated with relatively few adverse events compared with standard treatments such as chemotherapy. However, immune activation can potentially affect any organ system and a small fraction of patients are at risk for developing severe immune-related adverse events. Immune checkpoint inhibitors (ICIs) and other immunotherapeutic modalities such as cancer vaccines are in nascent stages of development for treatment of thymic epithelial tumors (TETs). Since the thymus plays a key role in the development of immune tolerance, thymic tumors have a unique biology which can influence the risk-benefit balance of immunotherapy. Indeed, early results from clinical trials have demonstrated clinical activity, albeit at a cost of a higher incidence of immune-related adverse events, which seem to particularly affect skeletal and cardiac muscle and the neuromuscular junction. In this paper we describe the effects of thymic physiology on the immune system and review the results of clinical trials that have evaluated immunotherapy for treatment of relapsed thymoma and thymic carcinoma. We review ongoing efforts to mitigate the risk of immune-related complications in patients with TETs receiving immunotherapy and offer our thoughts for making immunotherapy a feasible alternative for treatment of thymic tumors.

Time-dependent saddle-node bifurcation: Breaking time and the point of no return in a non-autonomous model of critical transitions

There is a growing awareness that catastrophic phenomena in biology and medicine can be mathematically represented in terms of saddle-node bifurcations. In particular, the term "tipping", or critical transition has in recent years entered the discourse of the general public in relation to ecology, medicine, and public health. The saddle-node bifurcation and its associated theory of catastrophe as put forth by Thom and Zeeman has seen applications in a wide range of fields including molecular biophysics, mesoscopic physics, and climate science. In this paper, we investigate a simple model of a non-autonomous system with a time-dependent parameter p(τ) and its corresponding "dynamic" (time-dependent) saddle-node bifurcation by the modern theory of non-autonomous dynamical systems. We show that the actual point of no return for a system undergoing tipping can be significantly delayed in comparison to the breaking time τ ^ at which the corresponding autonomous system with a time-independent parameter p a = p ( τ ^ ) undergoes a bifurcation. A dimensionless parameter α = λ p 0 3 V - 2 is introduced, in which λ is the curvature of the autonomous saddle-node bifurcation according to parameter p(τ), which has an initial value of p ₀ and a constant rate of change V. We find that the breaking time τ ^ is always less than the actual point of no return τ ^∗ after which the critical transition is irreversible; specifically, the relation τ * - τ ^ ≃ 2.338 ( λ V ) - 1 3 is analytically obtained. For a system with a small λV, there exists a significant window of opportunity ( τ ^ , τ ^∗) during which rapid reversal of the environment can save the system from catastrophe.

Coriolus Versicolor and Ganoderma Lucidum Related Natural Products as an Adjunct Therapy for Cancers: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Cancer incidence and mortality rates keep rising globally. Coriolus versicolor and Ganoderma lucidum related natural products are commonly applied as a complementary therapeutic option for different stages and types of cancers. The aim of this study is to evaluate the efficacy and safety of the products for cancer therapy. Methods: Randomized controlled trials were identified by systematic search over seven databases from inceptions to May 10, 2019. Two independent reviewers extracted data and assessed the study quality. Meta-analyses were performed to pool hazard ratio (HR), risk ratio (RR), mean differences (MD), and 95% CI using random-effects models. The sources of heterogeneity were explored by subgroup analyses and sensitivity analyses. Publication bias was detected by Funnel plots, Begg's test, and Egger's test. Results: Twenty-three trials involving 4,246 cancer patients were included in this work. C. versicolor and G. lucidum related natural products were significantly associated with lower risks of mortality (HR: 0.82; 95% CI: 0.72, 0.94) and higher total efficacy (RR: 1.30; 95% CI: 1.09, 1.55), but not associated with control rate (RR: 1.05; 95% CI: 0.96, 1.14) compared with control treatment. There was no significant difference between C. versicolor related natural products and control treatment in the effect on relapse-free survival (HR: 1.19; 95% CI: 0.91, 1.55). Compared with control treatment, C. versicolor and G. lucidum related natural products had a favorable effect on elevated levels of CD3 (MD: 9.03%; 95% CI: 2.10, 16.50) and CD4 (MD: 9.2%; 95% CI: 1.01, 17.39), but had no effect on the levels of CD8 (MD: -5.52%; 95% CI: -23.17, 12.13), CD4/CD8 (MD: 0.73; 95% CI:-0.45, 1.91), or NK(MD: 5.87%; 95% CI: -1.06, 12.8). Conclusion: In this meta-analysis, we found that C. versicolor and G. lucidum related natural products might have potential benefits on the overall survival and quality of life in cancer patients.

Impact of inflammatory signaling on radiation biodosimetry: mouse model of inflammatory bowel disease

Background

Ionizing Radiation (IR) is a known pro-inflammatory agent and in the process of development of biomarkers for radiation biodosimetry, a chronic inflammatory disease condition could act as a confounding factor. Hence, it is important to develop radiation signatures that can distinguish between IR-induced inflammatory responses and pre-existing disease. In this study, we compared the gene expression response of a genetically modified mouse model of inflammatory bowel disease (Il10^−/−) with that of a normal wild-type mouse to potentially develop transcriptomics-based biodosimetry markers that can predict radiation exposure in individuals regardless of pre-existing inflammatory condition.

Results

Wild-type (WT) and Il10^−/− mice were exposed to whole body irradiation of 7 Gy X-rays. Gene expression responses were studied using high throughput whole genome microarrays in peripheral blood 24 h post-irradiation. Analysis resulted in identification of 1962 and 1844 genes differentially expressed (p < 0.001, FDR < 10%) after radiation exposure in Il10^−/− and WT mice respectively. A set of 155 genes was also identified as differentially expressed between WT and Il10^−/− mice at the baseline pre-irradiation level. Gene ontology analysis revealed that the 155 baseline differentially expressed genes were mainly involved in inflammatory response, glutathione metabolism and collagen deposition. Analysis of radiation responsive genes revealed that innate immune response and p53 signaling processes were strongly associated with up-regulated genes, whereas B-cell development process was found to be significant amongst downregulated genes in the two genotypes. However, specific immune response pathways like MHC based antigen presentation, interferon signaling and hepatic fibrosis were associated with radiation responsive genes in Il10^−/− mice but not WT mice. Further analysis using the IPA prediction tool revealed significant differences in the predicted activation status of T-cell mediated signaling as well as regulators of inflammation between WT and Il10^−/− after irradiation.

Conclusions

Using a mouse model we established that an inflammatory disease condition could affect the expression of many radiation responsive genes. Nevertheless, we identified a panel of genes that, regardless of disease condition, could predict radiation exposure. Our results highlight the need for consideration of pre-existing conditions in the population in the process of development of reliable biodosimetry markers.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-5689-y) contains supplementary material, which is available to authorized users.

A Metabolism Toolbox for CAR T Therapy

The adoptive transfer of T cells expressing chimeric antigen receptors (CARs) through genetic engineering is one of the most promising new therapies for treating cancer patients. A robust CAR T cell-mediated anti-tumor response requires the coordination of nutrient and energy supplies with CAR T cell expansion and function. However, the high metabolic demands of tumor cells compromise the function of CAR T cells by competing for nutrients within the tumor microenvironment (TME). To substantially improve clinical outcomes of CAR T immunotherapy while treating solid tumors, it is essential to metabolically prepare CAR T cells to overcome the metabolic barriers imposed by the TME. In this review, we discuss a potential metabolism toolbox to improve the metabolic fitness of CAR T cells and maximize the efficacy of CAR T therapy.

Polymeric Co-Delivery Systems in Cancer Treatment: An Overview on Component Drugs' Dosage Ratio Effect

Multiple factors are involved in the development of cancers and their effects on survival rate. Many are related to chemo-resistance of tumor cells. Thus, treatment with a single therapeutic agent is often inadequate for successful cancer therapy. Ideally, combination therapy inhibits tumor growth through multiple pathways by enhancing the performance of each individual therapy, often resulting in a synergistic effect. Polymeric nanoparticles prepared from block co-polymers have been a popular platform for co-delivery of combinations of drugs associated with the multiple functional compartments within such nanoparticles. Various polymeric nanoparticles have been applied to achieve enhanced therapeutic efficacy in cancer therapy. However, reported drug ratios used in such systems often vary widely. Thus, the same combination of drugs may result in very different therapeutic outcomes. In this review, we investigated polymeric co-delivery systems used in cancer treatment and the drug combinations used in these systems for synergistic anti-cancer effect. Development of polymeric co-delivery systems for a maximized therapeutic effect requires a deeper understanding of the optimal ratio among therapeutic agents and the natural heterogenicity of tumors.

Effect of dendritic cell-based immunotherapy on hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND AIMS

Dendritic cell (DC)-based immunotherapy has recently been reported frequently in the treatment of hepatocellular carcinoma (HCC); however, its efficacy remains controversial. In this study, we aimed to evaluate the clinical efficacy of DC-based immunotherapy on HCC by conducting a systematic review and meta-analysis.

METHODS

PubMed, Cochrane Library, Embase and Web of Science were searched to identify clinical trials on DC-based immunotherapy for HCC published up to January 31, 2018. The articles were selected according to pre-established inclusion criteria and methodologic quality, and publication bias were evaluated.

RESULTS

A total of 1276 cases from 19 clinical trials were included. Compared with traditional treatment, further DC-based therapy enhanced the CD4⁺ T/CD8⁺ T ratio (standardized mean difference: 0.68, 95% confidence interval [CI] 0.46-0.89, P < 0.001); increased the 1-year, 18-month and 5-year progression-free survival (PFS) rate and the 1-year, 18-month and 2-year overall survival (OS) rate (relative risk > 1, P < 0.05), prolonged the median PFS time (median survival ratio [MSR]: 1.98, 95% CI: 1.60-2.46, P < 0.001) and median OS time (MSR: 1.72, 95% CI: 1.51-1.96, P < 0.001). Adverse reactions were mild.

CONCLUSIONS

DC-based therapy not only enhanced anti-tumor immunity, improved the survival rate and prolonged the survival time of HCC patients, but it was also safe. These findings will provide encouraging information for further development of DC-based immunotherapy as an adjuvant treatment for HCC. However, the results must be interpreted with caution because of the small study numbers, publication bias and the various of study designs, pre-treatment and therapeutic processes of DCs.

Potentiating cancer vaccine efficacy in liver cancer

Hepatocellular carcinoma (HCC) is the most common liver malignancy with a poor prognosis and an overall 5-year survival rate of approximately 5-6%. This is due because standard of care treatment options are limited and none of them shows a sufficient efficacy. HCC is an "inflammation-induced cancer" and preliminary preclinical and clinical data suggest that immunotherapeutic approaches may be a good alternative candidate for the treatment of HCC patients improving the dismal prognosis associated with this cancer. However, recent findings strongly suggest that an optimal immunotherapy in HCC requires the combination of an immune activator with immune modulators, aiming at compensating the strong liver immune suppressive microenvironment. One of the most promising strategy could be represented by the combination of a cancer vaccine with immunomodulatory drugs, such as chemotherapy and checkpoint inhibitors. Very limited examples of such combinatorial strategies have been evaluated in HCC to date, because HCC easily develops resistance to standard chemotherapy, which is also poorly tolerated by patients with liver cirrhosis. The present review describes the most update knowledge in this field.

Exploring the rationale for combining ionizing radiation and immune checkpoint blockade in head and neck cancer

BACKGROUND

The ability of radiation to enhance antitumor immunity under specific experimental conditions is well established. Here, we explore preclinical data and the rationale for combining different radiation doses and fractions with immune checkpoint blockade immunotherapy.

METHODS

We conducted a review of the literature.

RESULTS

The ability of high-dose or hypofractionated radiation to enhance antitumor immunity resulting in additive or synergistic tumor control when combined with checkpoint blockade is well studied. Whether low-dose daily fractionated radiation does the same is less well studied and available data suggests it may be immunosuppressive.

CONCLUSION

Although daily fractionated radiation is well established as the standard of care for the treatment of patients with head and neck cancer, how this radiation schema alters antitumor immunity needs further study. If the radiation doses and fractions alter antitumor immunity differently can have profound implications in the rational design of clinical trials investigating whether radiation can enhance response rates to immune checkpoint blockade.

Radiation improves antitumor effect of immune checkpoint inhibitor in murine hepatocellular carcinoma model

Background & aims

Although immunotherapy has emerged as an attractive therapy for refractory cancers, its limited efficacy in hepatocellular carcinoma (HCC) suggests the need for a combination strategy that can either enhance or complement therapeutic effect. We investigated whether combination of immune checkpoint blockade (ICB) and radiation could enhance antitumor effect in a murine HCC model.

Methods

Using murine HCC, HCa-1, the effect of radiation on programmed death-ligand1 (PD-L1) expression was determined by real-time PCR, flow cytometry, and western blotting. Signaling pathways involved in altered PD-L1 expression were examined. Tumor growth and survival rate were evaluated for a combination of anti-PD-L1 and radiation. Immunological parameters in the tumor were assessed using flow cytometry and histological study.

Results

Radiation upregulated PD-L1 expression in tumor cells through IFN-γ/STAT3 signaling, which could facilitate therapeutic action of anti-PD-L1. Combination of anti-PD-L1 and radiation significantly suppressed tumor growth compared to treatment with anti-PD-L1 alone or radiation alone group (P<0.01). Survival was significantly improved in the combination group compared to anti-PD-L1 alone or radiation alone group (7-week survival rate; 90% vs. 0% or 30%, respectively, P<0.001). The underlying mechanism involved increasing apoptosis, decreasing tumor cell proliferation, as well as restoration of CD8⁺ T cell functions.

Conclusions

The combination of anti-PD-L1 and radiation significantly improved the antitumor effect shown in tumor growth delay as well as in survival, supporting a novel combination strategy of immunoradiotherapy in HCC.

Combination of sorafenib and cytokine-induced killer cells in metastatic renal cell carcinoma: a potential regimen

Metastatic renal cell carcinoma (MRCC) exhibits primary resistance to both chemotherapy and radiotherapy. As an immunogenic cancer, MRCC is relatively sensitive to immunotherapy such as that with cytokines, immune checkpoint inhibitors and adoptive T-cell therapy. In addition, many targeted agents developed over the past decade exhibit greater efficacy than cytokines and have become the standard first-line therapy for MRCC. Several preclinical studies have shown that the targeted agent sorafenib possesses an immunomodulation function and may be suitable for combination with immunotherapy. Here, combinatorial therapy consisting of sorafenib and cytokine-induced killer cell immunotherapy was administered to an MRCC patient resulting in a synergistic effect without serious adverse effects. These results suggest a potential combinatorial regimen for MRCC patients.

Nanoparticle-Mediated Trapping of Wnt Family Member 5A in Tumor Microenvironments Enhances Immunotherapy for B-Raf Proto-Oncogene Mutant Melanoma

Development of an effective treatment against advanced tumors remains a major challenge for cancer immunotherapy. Approximately 50% of human melanoma is driven by B-Raf proto-oncogene mutation (BRAF mutant). Tumors with such mutation are desmoplastic, highly immunosuppressive, and often resistant to immune checkpoint therapies. We have shown that immunotherapy mediated by low-dose doxorubicin-induced immunogenic cell death was only partially effective for this type of tumor and not effective in long-term inhibition of tumor progression. Wnt family member 5A (Wnt5a), a signaling protein highly produced by BRAF mutant melanoma cells, has been implicated in inducing dendritic cell tolerance and tumor fibrosis, thus hindering effective antigen presentation and T-cell infiltration. We hypothesized that Wnt5a is a key molecule controlling the immunosuppressive tumor microenvironment in metastatic melanoma. Accordingly, we have designed and generated a trimeric trap protein, containing the extracellular domain of Fizzled 7 receptor that binds Wnt5a with a K_d ∼ 278 nM. Plasmid DNA encoding for the Wnt5a trap was delivered to the tumor by using cationic lipid-protamine-DNA nanoparticles. Expression of Wnt5a trap in the tumor, although transient, was greater than that of any other major organs including liver, resulting in a significant reduction of the Wnt5a level in the tumor microenvironment without systematic toxicity. Significantly, combination of Wnt5a trapping and low-dose doxorubicin showed great tumor growth inhibition and host survival prolongation. Our findings indicated that efficient local Wnt5a trapping significantly remodeled the immunosuppressive tumor microenvironment to facilitate immunogenic cell-death-mediated immunotherapy.

Sublethal exposure to alpha radiation (223Ra dichloride) enhances various carcinomas' sensitivity to lysis by antigen-specific cytotoxic T lymphocytes through calreticulin-mediated immunogenic modulation

Radium-223 dichloride (Xofigo^®; ²²³Ra) is an alpha-emitting radiopharmaceutical FDA-approved for the treatment of bone metastases in patients with advanced castration-resistant prostate cancer. It is also being examined clinically in patients with breast and lung carcinoma and patients with multiple myeloma. As with other forms of radiation, the aim of ²²³Ra is to reduce tumor burden by directly killing tumor cells. External beam (photon) and proton radiation have been shown to augment tumor sensitivity to antigen-specific CD8⁺ cytotoxic T lymphocytes (CTLs). However, little is known about whether treatment with ²²³Ra can also induce such immunogenic modulation in tumor cells that survive irradiation. We examined these effects in vitro by exposing human prostate, breast, and lung carcinoma cells to sublethal doses of ²²³Ra. ²²³Ra significantly enhanced T cell-mediated lysis of each tumor type by CD8⁺ CTLs specific for MUC-1, brachyury, and CEA tumor antigens. Immunofluorescence analysis revealed that the increase in CTL killing was accompanied by augmented protein expression of MHC-I and calreticulin in each tumor type, molecules that are essential for efficient antigen presentation. Enhanced tumor-cell lysis was facilitated by calreticulin surface translocation following ²²³Ra exposure. The phenotypic changes observed after treatment appear to be mediated by induction of the endoplasmic reticulum stress response pathway. By rendering tumor cells more susceptible to T cell-mediated lysis, ²²³Ra may potentially be effective in combination with various immunotherapies, particularly cancer vaccines that are designed to generate and expand patients’ endogenous antigen-specific T-cell populations against specific tumor antigens.

Androgen deprivation therapy sensitizes triple negative breast cancer cells to immune-mediated lysis through androgen receptor independent modulation of osteoprotegerin

Among breast cancer types, triple-negative breast cancer (TNBC) has the fewest treatment options and the lowest 5-year survival rate. Androgen receptor (AR) inhibition has displayed efficacy against breast cancer preclinically and is currently being examined clinically in AR positive TNBC patients. Androgen deprivation has been shown to induce immunogenic modulation; the alteration of tumor cell phenotype resulting in increased sensitivity to immune-mediated killing. We evaluated the ability of AR inhibition to reduce the growth and improve the immune-mediated killing of breast cancer cells with differing expression of the estrogen receptor and AR. While AR expression was required for the growth inhibitory effects of enzalutamide on breast cancer cells, both enzalutamide and abiraterone improved the sensitivity of breast cancer cells to immune-mediated lysis independent of detectable AR expression. This increase in sensitivity was linked to an increase in cell surface tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor expression as well as a significant reduction in the expression of osteoprotegerin (OPG). The reduction in OPG was further examined and found to be critical for the increase in sensitivity of AR- TNBC cells to immune-mediated killing. The data presented herein further support the use of AR inhibition therapy in the AR+ TNBC setting. These data, however, also support the consideration of AR inhibition therapy for the treatment of AR- TNBC, especially in combination with cancer immunotherapy, providing a potential novel therapeutic option for select patients.

Prostate Cancer Cells Express More Androgen Receptor (AR) Following Androgen Deprivation, Improving Recognition by AR-Specific T Cells

Androgen deprivation is the primary therapy for recurrent prostate cancer, and agents targeting the androgen receptor (AR) pathway continue to be developed. Because androgen-deprivation therapy (ADT) has immmunostimulatory effects as well as direct antitumor effects, AR-targeted therapies have been combined with other anticancer therapies, including immunotherapies. Here, we sought to study whether an antigen-specific mechanism of resistance to ADT (overexpression of the AR) may result in enhanced AR-specific T-cell immune recognition, and whether this might be strategically combined with an antitumor vaccine targeting the AR. Androgen deprivation increased AR expression in human and murine prostate tumor cells in vitro and in vivo The increased expression persisted over time. Increased AR expression was associated with recognition and cytolytic activity by AR-specific T cells. Furthermore, ADT combined with vaccination, specifically a DNA vaccine encoding the ligand-binding domain of the AR, led to improved antitumor responses as measured by tumor volumes and delays in the emergence of castrate-resistant prostate tumors in two murine prostate cancer models (Myc-CaP and prostate-specific PTEN-deficient mice). Together, these data suggest that ADT combined with AR-directed immunotherapy targets a major mechanism of resistance, overexpression of the AR. This combination may be more effective than ADT combined with other immunotherapeutic approaches. Cancer Immunol Res; 5(12); 1074-85. ©2017 AACR.

Combining anaerobic bacterial oncolysis with vaccination that blocks interleukin-10 signaling may achieve better outcomes for late stage cancer management

Late stage solid tumors cause significant cancer mortality rates worldwide and effective therapy remains a big challenge. Cancer therapeutic vaccines elicit tumor specific T cells that kill tumor cells yet often fail to result in tumor destruction because of the limited T cell response and the local immune-suppressive environment. Blocking interleukin 10 (IL-10) signaling at the time of therapeutic vaccination elicits much stronger T cell responses than vaccination without IL-10 blocking. Anaerobic oncolytic bacteria target hypoxic regions of the late stage tumor tissues which not only stops tumor growth but also provides a pro-inflammatory environment that may increase the effectiveness of a therapeutic vaccine by recruiting more effector T cells to tumor site. In this review, we argue that combining both bacterial and vaccine therapies may improve the efficiency of late stage cancer management.

Combination immunotherapy strategies in advanced non-small cell lung cancer (NSCLC): Does biological rationale meet clinical needs?

Immune checkpoint inhibitors (ICIs) have emerged as one of the main new therapeutic options for advanced non-small cell lung cancer (NSCLC) patients. Even though they demonstrated superiority towards standard chemotherapy in different disease settings, the response rates do not exceed 45% in highly molecularly selected patients. This is related to known limitations of the available biomarkers, as well to the complex and dynamic nature of tumor microenvironment. The study of the different strategies adopted by tumor cells to escape the immune system lays the basis of the new combination strategies. This review focuses on analyzing the biological rationale and early clinical data available concerning therapeutic strategies combining ICIs together, ICIs with different regimens and schedules of standard chemotherapy, ICIs with tyrosine kinase inhibitors, ICIs with antiangiogenic agents and ICs with radiotherapy.

Cell death response to anti-mitotic drug treatment in cell culture, mouse tumor model and the clinic

Anti-mitotic cancer drugs include classic microtubule-targeting drugs, such as taxanes and vinca alkaloids, and the newer spindle-targeting drugs, such as inhibitors of the motor protein; Kinesin-5 (aka KSP, Eg5, KIF11); and Aurora-A, Aurora-B and Polo-like kinases. Microtubule-targeting drugs are among the first line of chemotherapies for a wide spectrum of cancers, but patient responses vary greatly. We still lack understanding of how these drugs achieve a favorable therapeutic index, and why individual patient responses vary. Spindle-targeting drugs have so far shown disappointing results in the clinic, but it is possible that certain patients could benefit if we understand their mechanism of action better. Pre-clinical data from both cell culture and mouse tumor models showed that the cell death response is the most variable point of the drug action. Hence, in this review we focus on current mechanistic understanding of the cell death response to anti-mitotics. We first draw on extensive results from cell culture studies, and then cross-examine them with the more limited data from animal tumor models and the clinic. We end by discussing how cell type variation in cell death response might be harnessed to improve anti-mitotic chemotherapy by better patient stratification, new drug combinations and identification of novel targets for drug development.

Ionizing radiation sensitizes tumors to PD-L1 immune checkpoint blockade in orthotopic murine head and neck squamous cell carcinoma

Immunotherapy clinical trials targeting the programmed-death ligand axis (PD-1/PD-L1) show that most head and neck squamous cell carcinoma (HNSCC) patients are resistant to PD-1/PD-L1 inhibition. We investigated whether local radiation to the tumor can transform the immune landscape and render poorly immunogenic HNSCC tumors sensitive to PD-L1 inhibition. We used the first novel orthotopic model of HNSCC with genetically distinct murine cell lines. Tumors were resistant to PD-L1 checkpoint blockade, harbored minimal PD-L1 expression and tumor infiltrating lymphocytes at baseline, and were resistant to radiotherapy. The combination of radiation and PD-L1 inhibition significantly enhanced tumor control and improved survival. This was mediated in part through upregulation of PD-L1 on tumor cells and increased T-cell infiltration after RT, resulting in a highly inflamed tumor. Depletion of both CD4 and CD8 T-cells completely abrogated the effect of anti PD-L1 with radiation on tumor growth. Our findings provide evidence that radiation to the tumor can induce sensitivity to PD-L1 checkpoint blockade in orthotopic models of HNSCC. These findings have direct relevance to high risk HNSCC patients with poorly immunogenic tumors and who may benefit from combined radiation and checkpoint blockade.