Identification of increased dedifferentiation along the Prom1+ cancer cells in Müllerian adenosarcoma with sarcomatous overgrowth
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Targeting of TAMs: can we be more clever than cancer cells?
With increasing incidence and geography, cancer is one of the leading causes of death, reduced quality of life and disability worldwide. Principal progress in the development of new anticancer therapies, in improving the efficiency of immunotherapeutic tools, and in the personification of conventional therapies needs to consider cancer-specific and patient-specific programming of innate immunity. Intratumoral TAMs and their precursors, resident macrophages and monocytes, are principal regulators of tumor progression and therapy resistance. Our review summarizes the accumulated evidence for the subpopulations of TAMs and their increasing number of biomarkers, indicating their predictive value for the clinical parameters of carcinogenesis and therapy resistance, with a focus on solid cancers of non-infectious etiology. We present the state-of-the-art knowledge about the tumor-supporting functions of TAMs at all stages of tumor progression and highlight biomarkers, recently identified by single-cell and spatial analytical methods, that discriminate between tumor-promoting and tumor-inhibiting TAMs, where both subtypes express a combination of prototype M1 and M2 genes. Our review focuses on novel mechanisms involved in the crosstalk among epigenetic, signaling, transcriptional and metabolic pathways in TAMs. Particular attention has been given to the recently identified link between cancer cell metabolism and the epigenetic programming of TAMs by histone lactylation, which can be responsible for the unlimited protumoral programming of TAMs. Finally, we explain how TAMs interfere with currently used anticancer therapeutics and summarize the most advanced data from clinical trials, which we divide into four categories: inhibition of TAM survival and differentiation, inhibition of monocyte/TAM recruitment into tumors, functional reprogramming of TAMs, and genetic enhancement of macrophages.
Enhancer reprogramming: critical roles in cancer and promising therapeutic strategies
Transcriptional dysregulation is a hallmark of cancer initiation and progression, driven by genetic and epigenetic alterations. Enhancer reprogramming has emerged as a pivotal driver of carcinogenesis, with cancer cells often relying on aberrant transcriptional programs. The advent of high-throughput sequencing technologies has provided critical insights into enhancer reprogramming events and their role in malignancy. While targeting enhancers presents a promising therapeutic strategy, significant challenges remain. These include the off-target effects of enhancer-targeting technologies, the complexity and redundancy of enhancer networks, and the dynamic nature of enhancer reprogramming, which may contribute to therapeutic resistance. This review comprehensively encapsulates the structural attributes of enhancers, delineates the mechanisms underlying their dysregulation in malignant transformation, and evaluates the therapeutic opportunities and limitations associated with targeting enhancers in cancer.
Targeting the splicing factor SNRPB inhibits endometrial cancer progression by retaining the POLD1 intron
Dysregulated alternative splicing has been closely linked to the initiation and progression of tumors. Nevertheless, the precise molecular mechanisms through which splicing factors regulate endometrial cancer progression are still not fully understood. This study demonstrated elevated expression of the splicing factor SNRPB in endometrial cancer samples. Furthermore, our findings indicate that high SNRPB expression is correlated with poor prognosis in patients with endometrial cancer. Functionally, SNRPB inhibition hindered the proliferative and metastatic capacities of endometrial cancer cells. Mechanistically, we revealed that SNRPB knockdown decreased POLD1 expression and that POLD1 intron 22 was retained after SNRPB silencing in endometrial cancer cells, as determined via RNA sequencing data analysis. The retained intron 22 of POLD1 created a premature termination codon, leading to the absence of amino acids 941–1,107 and the loss of the site of interaction with PCNA, which is essential for POLD1 enzyme activity. In addition, POLD1 depletion decreased the increase in the malignancy of endometrial cancer cells overexpressing SNRPB. Furthermore, miR-654-5p was found to bind directly to the 3′ untranslated region of SNRPB, resulting in SNRPB expression inhibition in endometrial cancer. Antisense oligonucleotide-mediated SNRPB inhibition led to a decrease in the growth capacity of a cell-derived xenograft model and a patient with endometrial cancer-derived xenograft model. Overall, SNRPB promotes the efficient splicing of POLD1 by regulating intron retention, ultimately contributing to high POLD1 expression in endometrial cancer. The oncogenic SNRPB–POLD1 axis is an interesting therapeutic target for endometrial cancer, and antisense oligonucleotide-mediated silencing of SNRPB may constitute a promising therapeutic approach for treating patients with endometrial cancer.
Implantation of engineered adipocytes suppresses tumor progression in cancer models
Tumors exhibit an increased ability to obtain and metabolize nutrients. Here, we implant engineered adipocytes that outcompete tumors for nutrients and show that they can substantially reduce cancer progression, a technology termed adipose manipulation transplantation (AMT). Adipocytes engineered to use increased amounts of glucose and fatty acids by upregulating UCP1 were placed alongside cancer cells or xenografts, leading to significant cancer suppression. Transplanting modulated adipose organoids in pancreatic or breast cancer genetic mouse models suppressed their growth and decreased angiogenesis and hypoxia. Co-culturing patient-derived engineered adipocytes with tumor organoids from dissected human breast cancers significantly suppressed cancer progression and proliferation. In addition, cancer growth was impaired by inducing engineered adipose organoids to outcompete tumors using tetracycline or placing them in an integrated cell-scaffold delivery platform and implanting them next to the tumor. Finally, we show that upregulating UPP1 in adipose organoids can outcompete a uridine-dependent pancreatic ductal adenocarcinoma for uridine and suppress its growth, demonstrating the potential customization of AMT.
Mitochondrial priming and response to BH3 mimetics in “one-two punch” senogenic-senolytic strategies
A one-two punch sequential regimen of senescence-inducing agents followed by senolytic drugs has emerged as a novel therapeutic strategy in cancer. Unfortunately, cancer cells undergoing therapy-induced senescence (TIS) vary widely in their sensitivity to senotherapeutics, and companion diagnostics to predict the response of TIS cancer cells to a specific senolytic drug are lacking. Here, we hypothesized that the ability of the BH3 profiling assay to functionally measure the mitochondrial priming state—the proximity to the apoptotic threshold—and the dependencies on pro-survival BCL-2 family proteins can be exploited to inform the sensitivity of TIS cancer cells to BH3-mimetics. Replicative, mitotic, oxidative, and genotoxic forms of TIS were induced in p16-null/p53-proficient, BAX-deficient, and BRCA1-mutant cancer cells using mechanistically distinct TIS-inducing cancer therapeutics, including palbociclib, alisertib, doxorubicin, bleomycin, and olaparib. When the overall state of mitochondrial priming and competence was determined using activator peptides, the expected increase in overall mitochondrial priming was an exception rather than a generalizable feature across TIS phenotypes. A higher level of overall priming paralleled a higher sensitivity of competent TIS cancer cells to BCL-2/BCL-xL- and BCL-xL-targeted inhibitors when comparing TIS phenotypes among themselves. Unexpectedly, however, TIS cancer cells remained equally or even less overally primed than their proliferative counterparts. When sensitizing peptides were used to map dependencies on anti-apoptotic BCL-2 family proteins, competent TIS cancer cells appeared to share a dependency on BCL-xL. Furthermore, regardless of senescence-inducing therapeutic, stable/transient senescence acquisition, or genetic context, all TIS phenotypes shared a variable but significant senolytic response to the BCL-xL-selective BH3 mimetic A1331852. These findings may help to rethink the traditional assumption of the primed apoptotic landscape of TIS cancer cells. BCL-xL is a conserved anti-apoptotic effector of the TIS BCL2/BH3 interactome that can be exploited to maximize the efficacy of “one-two punch” senogenic-senolytic strategies.
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