Immune evasion of dormant disseminated tumor cells is due to their scarcity and can be overcome by T cell immunotherapies

The period between "successful" treatment of localized breast cancer and the onset of distant metastasis can last many years, representing an unexploited window to eradicate disseminated disease and prevent metastases. We find that the source of recurrence-disseminated tumor cells (DTCs) -evade endogenous immunity directed against tumor neoantigens. Although DTCs downregulate major histocompatibility complex I, this does not preclude recognition by conventional T cells. Instead, the scarcity of interactions between two relatively rare populations-DTCs and endogenous antigen-specific T cells-underlies DTC persistence. This scarcity is overcome by any one of three immunotherapies that increase the number of tumor-specific T cells: T cell-based vaccination, or adoptive transfer of T cell receptor or chimeric antigen receptor T cells. Each approach achieves robust DTC elimination, motivating discovery of MHC-restricted and -unrestricted DTC antigens that can be targeted with T cell-based immunotherapies to eliminate the reservoir of metastasis-initiating cells in patients.

The PI3K/mTOR inhibitor Gedatolisib eliminates dormant breast cancer cells in organotypic culture, but fails to prevent metastasis in preclinical settings

Dormant, disseminated tumor cells (DTCs) are thought to be the source of breast cancer metastases several years or even decades after initial treatment. To date, a selective therapy that leads to their elimination has not been discovered. While dormant DTCs resist chemotherapy, evidence suggests that this resistance is driven not by their lack of proliferation, but by their engagement of the surrounding microenvironment, via integrin‐β1‐mediated interactions. Because integrin‐β1‐targeted agents have not been translated readily to the clinic, signaling nodes downstream of integrin‐β1 could serve as attractive therapeutic targets in order to sensitize dormant DTCs to therapy. By probing a number of kinases downstream of integrin‐β1, we determined that PI3K inhibition with either a tool compounds or a compound (PF‐05212384; aka Gedatolisib) in clinical trials robustly sensitizes quiescent breast tumor cells seeded in organotypic bone marrow cultures to chemotherapy. These results motivated the preclinical study of whether Gedatolisib—with or without genotoxic therapy—would reduce DTC burden and prevent metastases. Despite promising results in organotypic culture, Gedatolisib failed to reduce DTC burden or delay, reduce or prevent metastasis in murine models of either triple‐negative or estrogen receptor‐positive breast cancer dissemination and metastasis. This result held true whether analyzing Gedatolisib on its own (vs. vehicle‐treated animals) or in combination with dose‐dense doxorubicin and cyclophosphamide (vs. animals treated only with dose‐dense chemotherapies). These data suggest that PI3K is not the node downstream of integrin‐β1 that confers chemotherapeutic resistance to DTCs. More broadly, they cast doubt on the strategy to target PI3K in order to eliminate DTCs and prevent breast cancer metastasis.

Targeting the perivascular niche sensitizes disseminated tumour cells to chemotherapy

The presence of disseminated tumour cells (DTCs) in bone marrow is predictive of poor metastasis-free survival of patients with breast cancer with localized disease. DTCs persist in distant tissues despite systemic administration of adjuvant chemotherapy. Many assume that this is because the majority of DTCs are quiescent. Here, we challenge this notion and provide evidence that the microenvironment of DTCs protects them from chemotherapy, independent of cell cycle status. We show that chemoresistant DTCs occupy the perivascular niche (PVN) of distant tissues, where they are protected from therapy by vascular endothelium. Inhibiting integrin-mediated interactions between DTCs and the PVN, driven partly by endothelial-derived von Willebrand factor and vascular cell adhesion molecule 1, sensitizes DTCs to chemotherapy. Importantly, chemosensitization is achieved without inducing DTC proliferation or exacerbating chemotherapy-associated toxicities, and ultimately results in prevention of bone metastasis. This suggests that prefacing adjuvant therapy with integrin inhibitors is a viable clinical strategy to eradicate DTCs and prevent metastasis.

The distinction between the antismoking and nonsmokers' rights movements

In a recent article Markle and Troyer analyze the cigarette controversy as a status battle between pro and antismoking vested interests. They argue that the purpose of the antismoking movement is to lower the status of smokers, symbolically to label smoking as undesirable, unacceptable, and socially deviant behavior, and, hence, to stigmatize and denigrate smokers as social misfits. In this paper it is argued that it is important to extend the analysis by drawing a distinction between the general antismoking movement and the nonsmokers' rights movement. It is shown that the nonsmokers' right movement in its pure form is devoted solely to the protection of the rights of nonsmokers and does not endorse, and may even oppose, other elements of the general antismoking movement. The essential motivation is not the denigration of smokers but rather is the refusal of nonsmokers to be victimized by the oppressive conditions of the social support system of smoking that gives smokers the implicit right to smoke in shared areas and puts bothered nonsmokers on the defensive.

Reported physiological and psychological symptoms of tobacco smoke pollution in nonsmoking and smoking college students

A 147-item questionnaire concerning the relevance of the nonsmokers' right movement to college and university campuses was administered to 307 University of New Hampshire undergraduates. The fourth section of the questionnaire consisted of 28 questions on symptoms caused by smoke pollution. Responses to these questions were given on a five-category frequency of occurrence scale. Frequencies, descriptive statistics, and t tests contrasting current smokers from nonsmokers were presented. Generally sizable percentages of nonsmokers reported adverse physiological and psychological symptoms from tobacco smoke pollution. Smokers reported a similar pattern of responding but at lower frequencies of occurrence.

A brief survey of beliefs about the effects of tobacco smoke pollution on intellectual performance in college classrooms

A subset of four questions was selected from a longer questionnaire to survey beliefs about the effects of tobacco smoke pollution on intellectual performance in college classrooms. Sizable majorities of both the 246 nonsmokers and 61 smokers believed that nonsmoking students with smoke-aversive handicaps suffer discriminatory treatment because of smoke pollution. The need for additional survey and experimental studies is presented.

Normative beliefs about tobacco smoking on campus in relation to an exposititon of the viewpoint of the nonsmokers' rights movement

A 147-item questionnaire on the effects of tobacco smoking on campus was administered to 307 University of New Hampshire undergraduates. Questions were asked in relation to an exposition of the viewpoint of the nonsmokers' rights movement. A group of 21 items, dealing with attitudes and normative beliefs related to issues of smokers' and nonsmokers' rights, were selected for analysis in this paper. Descriptive statistics and t tests contrasting the smokers and nonsmokers were presented. A majority of both groups agreed that smoking on campus should be limited to special areas and agreed that the right to breathe smoke-free air is the primary right. Nonsmokers in particular affirmed that nonsmokers who find smoke aversive often hide their true feelings and do not request that smokers abstain. Interpretation of results focused upon the normative structure of our society as the key element involved in perpetuating smoking in shared areas. At the present time it appears that smoking in these areas without permission is defined as normative (i.e., appropriate), whereas objecting is implicitly characterized as a norm violation.

An experimental analysis of the Chevreul pendulum illusion

An investigation was performed, with the use of 60 male and female college students, to quantify the Chevreul pendulum illusory effect, the tendency of a small pendulum, when suspended from the hand and imaginatively concentrated upon, to oscillate seemingly of its own accord. By means of a time exposure photographic measurement technique, strong parametric influences of the pendulum's sinusoidal motion were isolated. It was found that the pendulum effect was enhanced when (a) attentional capacity remained undivided, (b) the amount of musculature used to suspend the pendulum was at a maximum, (c) oscillating visual and auditory external stimuli were present, and (d) females were Ss. In addition, the visual stimulus was found to be superior to its auditory counterpart. The relevance of ideomotor and visual capture interpretations of covert muscle processes in the pendulum illusion was discussed.

An auditory analog of the Stroop Test

With use of a tape-recorded auditory method of stimulus presentation, 112 undergraduates were required to identify the tonal concepts of high and low when these concepts were symbolically coded both in terms of high and low pitches of voice and by the spoken words "high" and "low." Trials consisted of 44-item sequential identifications of the concepts. Results were consistent with those in other realms. With use of a speeded accuracy criterion, findings were that Ss could identify the concepts faster from word symbols than from pitch symbols and faster from the two types of symbol information correctly matched than from either component type alone. More interference was produced when half of the symbols on a trial were mismatched and the other half matched than when all of the symbols were mismatched. Interference effects in both directions were found, but there was a larger interference of words on pitch than of pitch on words.

Information processing analysis of the Chevreul pendulum illusion

An information processing investigation was performed to quantify the Chevreul pendulum effect: the tendency of a small pendulum, when suspended from the hand and imaginatively concentrated on, to oscillate seemingly of its own accord. Using a time exposure photographic measurement technique, electronically automated visual and auditory imaginal prompts were presented to the subject during imaginal processing tasks. It was found that the pendulum effect was enhanced when vision of actual pendulum oscillations was permitted and visual or auditory spatially oscillating stimuli were present. Visual spatially oscillating stimuli were superior to their auditory counterparts. Results were discussed in terms of ideomotor and visual capture interpretations of signal and imaginal processing.

Information processing analysis of the Chevreul pendulum illusion

An information processing investigation was performed to quantify the Chevreul pendulum effect: the tendency of a small pendulum, when suspended from the hand and imaginatively concentrated on, to oscillate seemingly of its own accord. Using a time exposure photographic measurement technique, electronically automated visual and auditory imaginal prompts were presented to the subject during imaginal processing tasks. It was found that the pendulum effect was enhanced when vision of actual pendulum oscillations was permitted and visual or auditory spatially oscillating stimuli were present. Visual spatially oscillating stimuli were superior to their auditory counterparts. Results were discussed in terms of ideomotor and visual capture interpretations of signal and imaginal processing.

Response during Sleep with Intervening Waking Amnesia

During stage 1 sleep, subjects responded to suggestions on two or more nights, up to 5 months apart. While they were awake they did not recall the material to which they successfully responded while asleep on a subsequent night.