The microbiome and human cancer

Science ◽  
2021 ◽  
Vol 371 (6536) ◽  
pp. eabc4552
Author(s):  
Gregory D. Sepich-Poore ◽  
Laurence Zitvogel ◽  
Ravid Straussman ◽  
Jeff Hasty ◽  
Jennifer A. Wargo ◽  
...  

Microbial roles in cancer formation, diagnosis, prognosis, and treatment have been disputed for centuries. Recent studies have provocatively claimed that bacteria, viruses, and/or fungi are pervasive among cancers, key actors in cancer immunotherapy, and engineerable to treat metastases. Despite these findings, the number of microbes known to directly cause carcinogenesis remains small. Critically evaluating and building frameworks for such evidence in light of modern cancer biology is an important task. In this Review, we delineate between causal and complicit roles of microbes in cancer and trace common themes of their influence through the host’s immune system, herein defined as the immuno-oncology-microbiome axis. We further review evidence for intratumoral microbes and approaches that manipulate the host’s gut or tumor microbiome while projecting the next phase of experimental discovery.


2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Vinod Vijay Subhash ◽  
Mei Shi Yeo ◽  
Woei Loon Tan ◽  
Wei Peng Yong

In cancer biology, cells and molecules that form the fundamental components of the tumor microenvironment play a major role in tumor initiation, and progression as well as responses to therapy. Therapeutic approaches that would enable and harness the immune system to target tumor cells mark the future of anticancer therapy as it could induce an immunological memory specific to the tumor type and further enhance tumor regression and relapse-free survival in cancer patients. Gastric cancer is one of the leading causes of cancer-related mortalities that has a modest survival benefit from existing treatment options. The advent of immunotherapy presents us with new approaches in gastric cancer treatment where adaptive cell therapies, cancer vaccines, and antibody therapies have all been used with promising outcomes. In this paper, we review the current advances and prospects in the gastric cancer immunotherapy. Special focus is laid on new strategies and clinical trials that attempt to enhance the efficacy of various immunotherapeutic modalities in gastric cancer.



2021 ◽  
Vol 9 (9) ◽  
pp. e002688
Author(s):  
Christina S E Carroll ◽  
Erin R Andrew ◽  
Laeeq Malik ◽  
Kathryn F Elliott ◽  
Moira Brennan ◽  
...  

BackgroundWe describe intratumoral injection of a slow-release emulsion of killed mycobacteria (complete Freund’s adjuvant (CFA)) in three preclinical species and in human cancer patients.MethodsEfficacy and safety were tested in mammary tumors in mice, in mastocytomas in mice and dogs, and in equine melanomas. In mice, survival, tumor growth, and tumor infiltration by six immune cell subsets (by flow cytometry) were investigated and analyzed using Cox proportional hazards, a random slopes model, and a full factorial model, respectively. Tumor growth and histology were investigated in dogs and horses, as well as survival and tumor immunohistochemistry in dogs. Tumor biopsies were taken from human cancer patients on day 5 (all patients) and day 28 (some patients) of treatment and analyzed by histology. CT scans are provided from one patient.ResultsSignificantly extended survival was observed in mouse P815 and 4T1 tumor models. Complete tumor regressions were observed in all three non-human species (6/186 (3%) of mouse mastocytomas; 3/14 (21%) of canine mastocytomas and 2/11 (18%) of equine melanomas). Evidence of systemic immune responses (regression of non-injected metastases) was also observed. Analysis of immune cells infiltrating mastocytoma tumors in mice showed that early neutrophil infiltration was predictive of treatment benefit. Analysis of the site of mastocytoma regression in dogs weeks or months after treatment demonstrated increased B and T cell infiltrates. Thus, activation of the innate immune system alone may be sufficient for regression of some injected tumors, followed by activation of the acquired immune system which can mediate regression of non-injected metastases. Finally, we report on the use of CFA in 12 human cancer patients. Treatment was well tolerated. CT scans showing tumor regression in a patient with late-stage renal cancer are provided.ConclusionOur data demonstrate that intratumoral injection of CFA has major antitumor effects in a proportion of treated animals and is safe for use in human cancer patients. Further trials in human cancer patients are therefore warranted. Our novel treatment provides a simple and inexpensive cancer immunotherapy, immediately applicable to a wide range of solid tumors, and is suitable to patients in developing countries and advanced care settings.



Author(s):  
Michelle N. Messmer ◽  
Colleen S. Netherby ◽  
Scott I. Abrams

The immune system serves as an integral checkpoint to developing malignancies. However, when cancer ultimately becomes detectable, this implicates an inherent failure of effective immune control. One constant theme in cancer biology has been the ability of these “diseases,” in particular, ovarian cancer, to compromise immune-mediated mechanisms of neoplastic control. These empirical observations have subsequently laid the scientific foundation to investigate ways in which the immune system can be reengaged as a powerful therapeutic weapon, singly or in combination with other modalities. This field has been coined “cancer immunotherapy” and, importantly, strong progress has been made to date to justify its feasibility and potential merit. This chapter focuses on the fundamental immunologic principles that have guided the development of the cancer immunotherapy concept, as well as details both the successes and the limitations of cancer immunotherapy in patients with metastatic ovarian cancer.



2020 ◽  
Vol 27 (34) ◽  
pp. 5654-5674 ◽  
Author(s):  
Daniel H. O’ Donovan ◽  
Yumeng Mao ◽  
Deanna A. Mele

The recent success of checkpoint blocking antibodies has sparked a revolution in cancer immunotherapy. Checkpoint inhibition activates the adaptive immune system leading to durable responses across a range of tumor types, although this response is limited to patient populations with pre-existing tumor-infiltrating T cells. Strategies to stimulate the immune system to prime an antitumor response are of intense interest and several groups are now working to develop agents to activate the Pattern Recognition Receptors (PRRs), proteins which detect pathogenic and damageassociated molecules and respond by activating the innate immune response. Although early efforts focused on the Toll-like Receptor (TLR) family of membrane-bound PRRs, TLR activation has been associated with both pro- and antitumor effects. Nonetheless, TLR agonists have been deployed as potential anticancer agents in a range of clinical trials. More recently, the cytosolic PRR Stimulator of IFN Genes (STING) has attracted attention as another promising target for anticancer drug development, with early clinical data beginning to emerge. Besides STING, several other cytosolic PRR targets have likewise captured the interest of the drug discovery community, including the RIG-Ilike Receptors (RLRs) and NOD-like Receptors (NLRs). In this review, we describe the outlook for activators of PRRs as anticancer therapeutic agents and contrast the earlier generation of TLR agonists with the emerging focus on cytosolic PRR activators, both as single agents and in combination with other cancer immunotherapies.



2006 ◽  
Vol 13 (4) ◽  
pp. 141-143 ◽  
Author(s):  
T. Hahn ◽  
Emmanuel Akporiaye

Human tumours have evolved intricate mechanisms to evade the immune system, either by avoiding recognition or by inhibiting and eliminating immune cells. [...]



Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3596
Author(s):  
Reza Bayat Mokhtari ◽  
Manpreet Sambi ◽  
Bessi Qorri ◽  
Narges Baluch ◽  
Neda Ashayeri ◽  
...  

Cancer immunotherapy harnesses the immune system by targeting tumor cells that express antigens recognized by immune system cells, thus leading to tumor rejection. These tumor-associated antigens include tumor-specific shared antigens, differentiation antigens, protein products of mutated genes and rearrangements unique to tumor cells, overexpressed tissue-specific antigens, and exogenous viral proteins. However, the development of effective therapeutic approaches has proven difficult, mainly because these tumor antigens are shielded, and cells primarily express self-derived antigens. Despite innovative and notable advances in immunotherapy, challenges associated with variable patient response rates and efficacy on select tumors minimize the overall effectiveness of immunotherapy. Variations observed in response rates to immunotherapy are due to multiple factors, including adaptative resistance, competency, and a diversity of individual immune systems, including cancer stem cells in the tumor microenvironment, composition of the gut microbiota, and broad limitations of current immunotherapeutic approaches. New approaches are positioned to improve the immune response and increase the efficacy of immunotherapies, highlighting the challenges that the current global COVID-19 pandemic places on the present state of immunotherapy.



Cancer ◽  
1985 ◽  
Vol 56 (6) ◽  
pp. 1366-1373 ◽  
Author(s):  
Yashar Hirshaut ◽  
Susan F. Slovin


2021 ◽  
Vol 22 (15) ◽  
pp. 8037
Author(s):  
Akshita Chauhan ◽  
Tabassum Khan ◽  
Abdelwahab Omri

The aim of cancer immunotherapy is to reactivate autoimmune responses to combat cancer cells. To stimulate the immune system, immunomodulators, such as adjuvants, cytokines, vaccines, and checkpoint inhibitors, are extensively designed and studied. Immunomodulators have several drawbacks, such as drug instability, limited half-life, rapid drug clearance, and uncontrolled immune responses when used directly in cancer immunotherapy. Several strategies have been used to overcome these limitations. A simple and effective approach is the loading of immunomodulators onto gold-based nanoparticles (GNPs). As gold is highly biocompatible, GNPs can be administered intravenously, which aids in increasing cancer cell permeability and retention time. Various gold nanoplatforms, including nanospheres, nanoshells, nanorods, nanocages, and nanostars have been effectively used in cancer immunotherapy. Gold nanostars (GNS) are one of the most promising GNP platforms because of their unusual star-shaped geometry, which significantly increases light absorption and provides high photon-to-heat conversion efficiency due to the plasmonic effect. As a result, GNPs are a useful vehicle for delivering antigens and adjuvants that support the immune system in killing tumor cells by facilitating or activating cytotoxic T lymphocytes. This review represents recent progress in encapsulating immunomodulators into GNPs for utility in a cancer immunotherapeutic regimen.



2003 ◽  
Vol 198 (11) ◽  
pp. 1753-1757 ◽  
Author(s):  
Madhav V. Dhodapkar ◽  
Joseph Krasovsky ◽  
Keren Osman ◽  
Matthew D. Geller

Most approaches targeting the immune system against tumors have focused on patients with established tumors. However, whether the immune system can recognize preneoplastic stages of human cancer is not known. Here we show that patients with preneoplastic gammopathy mount a vigorous T cell response to autologous premalignant cells. This preneoplasia-specific CD4+ and CD8+ T cell response is detected in freshly isolated T cells from the BM. T cells from myeloma marrow lack this tumor-specific rapid effector function. These data provide direct evidence for tumor specific immune recognition in human preneoplasia and suggest a possible role for the immune system in influencing the early growth of transformed cells, long before the development of clinical cancer.



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