Molecular landscape and functional characterization of centrosome amplification in ovarian cancer

Macrophage-hitchhiked, effervescence-induced nanoemulsions for enhanced oral chemotherapy and immunotherapy: Impact on absorption route

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal cancer. Paclitaxel (PTX), typically administered intravenously (IV) as chemotherapy, shows promise for triggering immunogenic cell death (ICD) and may serve as a potential immunotherapy. This study introduces an oral PTX delivery method using an enteric-coated gelatin capsule containing capric acid oil and an effervescent agent, optionally with decylamine-conjugated β-glucans (DA-βGlus). Upon dissolving in the small intestine, the capsule undergoes an effervescence reaction that produces emulsified oil droplets (ODs) by bile salts, forming either Bared/ODs/PTX or DA-βGlus/ODs/PTX, with the latter featuring surface-attached DA-βGlus. The study evaluates the oral absorption, pharmacokinetics, and therapeutic efficacy of these formulations, comparing them to IV administration. IV PTX causes rapid spikes in plasma concentration, quick metabolism, and elimination, which can be unsafe. In contrast, the oral delivery system maintains consistent drug levels in the bloodstream for longer periods, improving overall effectiveness. Bared/ODs/PTX follows conventional fat absorption pathways, limiting tumor targeting. On the other hand, DA-βGlus/ODs/PTX uses DA-βGlus to enhance specificity for tumors through endogenous macrophage-mediated transport, effectively acting as "cellular tumor-seeking vehicles". This method reduces tumor stroma fibrosis, delivers PTX precisely, induces apoptosis, triggers PTX-induced ICD, and enhances cytotoxic T cell responses, augmenting targeted anti-PDAC strategies.

Bystanders or active players: the role of extra centrosomes as signaling hubs

Centrosomes serve as microtubule-organizing organelles that function in spindle pole organization, cell cycle progression, and cilia formation. A non-canonical role of centrosomes that has gained traction in recent years is the ability to act as signal transduction centers. Centrosome amplification, which includes numerical and structural aberrations of centrosomes, is a candidate hallmark of cancer. The function of centrosomes as signaling centers in cancer cells with centrosome amplification is poorly understood. Establishing a model of how cancer cells utilize centrosomes as signaling platforms will help elucidate the role of extra centrosomes in cancer cell survival and tumorigenesis. Centrosomes act in a diverse array of cellular processes, including cell migration, cell cycle progression, and proteasomal degradation. Given that cancer cells with amplified centrosomes exhibit an increased number and larger area of these signaling platforms, extra centrosomes may be acting to promote tumor development by enhancing signaling kinetics in pathways that are essential for the formation and growth of cancer. In this review, we identify the processes centrosomes are involved in as signal transduction platforms and highlight ways in which cancer cells with centrosome amplification may be taking advantage of these mechanisms.

Centromeres in cancer: Unraveling the link between chromosomal instability and tumorigenesis

Centromeres are critical structures involved in chromosome segregation, maintaining genomic stability, and facilitating the accurate transmission of genetic information. They are key in coordinating the assembly and help keep the correct structure, location, and function of the kinetochore, a proteinaceous structure vital for ensuring proper chromosome segregation during cell division. Abnormalities in centromere structure can lead to aneuploidy or chromosomal instability, which have been implicated in various diseases, including cancer. Accordingly, abnormalities in centromeres, such as structural rearrangements and dysregulation of centromere-associated proteins, disrupt gene function, leading to uncontrolled cell growth and tumor progression. For instance, altered expression of CENP-A, CENP-E, and others such as BUB1, BUBR1, MAD1, and INCENP, have been shown to ascribe to centromere over-amplification, chromosome missegregation, aneuploidy, and chromosomal instability; this, in turn, can culminate in tumor progression. These centromere abnormalities also promoted tumor heterogeneity by generating genetically diverse cell populations within tumors. Advanced techniques like fluorescence in situ hybridization (FISH) and chromosomal microarray analysis are crucial for detecting centromere abnormalities, enabling accurate cancer classification and tailored treatment strategies. Researchers are exploring strategies to disrupt centromere-associated proteins for targeted cancer therapies. Thus, this review explores centromere abnormalities in cancer, their molecular mechanisms, diagnostic implications, and therapeutic targeting. It aims to advance our understanding of centromeres' role in cancer and develop advanced diagnostic tools and targeted therapies for improved cancer management and treatment.

Ku70 Binding to YAP Alters PARP1 Ubiquitination to Regulate Genome Stability and Tumorigenesis

Yes-associated protein (YAP) is a central player in cancer development, with functions extending beyond its recognized role in cell growth regulation. Recent work has identified a link between YAP/transcriptional coactivator with PDZ-binding motif (TAZ) and the DNA damage response. Here, we investigated the mechanistic underpinnings of the cross-talk between DNA damage repair and YAP activity. Ku70, a key component of the nonhomologous end joining pathway to repair DNA damage, engaged in a dynamic competition with TEAD4 for binding to YAP, limiting the transcriptional activity of YAP. Depletion of Ku70 enhanced interaction between YAP and TEAD4 and boosted YAP transcriptional capacity. Consequently, Ku70 loss enhanced tumorigenesis in colon cancer and hepatocellular carcinoma (HCC) in vivo. YAP impeded DNA damage repair and elevated genome instability by inducing PARP1 degradation through the SMURF2-mediated ubiquitin-proteasome pathway. Analysis of samples from patients with HCC substantiated the link between Ku70 expression, YAP activity, PARP1 levels, and genome instability. In conclusion, this research provides insight into the mechanistic interactions between YAP and key regulators of DNA damage repair, highlighting the role of a Ku70-YAP-PARP1 axis in preserving genome stability. Significance: Increased yes-associated protein transcriptional activity stimulated by loss of Ku70 induces PARP1 degradation by upregulating SMURF2 to inhibit DNA damage, driving genome instability and tumorigenesis.

Single-cell transcriptome analysis revealed heterogeneity in glycolysis and identified IGF2 as a therapeutic target for ovarian cancer subtypes

BACKGROUND

As the most malignant tumor of the female reproductive system, ovarian cancer (OC) has garnered increasing attention. The Warburg effect, driven by glycolysis, accounts for tumor cell proliferation under aerobic conditions. However, the metabolic heterogeneity linked to glycolysis in OC remains elusive.

METHODS

We integrated single-cell data with OC to score glycolysis level in tumor cell subclusters. This led to the identification of a subcluster predominantly characterized by glycolysis, with a strong correlation to patient prognosis. Core transcription factors were pinpointed using hdWGCNA and metaVIPER. A specific transcription factor regulatory network was then constructed. A glycolysis-related prognostic model was developed and tested for estimating OC prognosis with a total of 85 machine-learning combinations, focusing on specific upregulated genes of two subtypes. We identified IGF2 as a key within the prognostic model and investigated its impact on OC progression and drug resistance through in vitro experiments, including the transwell assay, lactate production detection, and the CCK-8 assay.

RESULTS

Analysis showed that the Malignant 7 subcluster was primarily related to glycolysis. Two OC molecular subtypes, CS1 and CS2, were identified with distinct clinical, biological, and microenvironmental traits. A prognostic model was built, and IGF2 emerged as a key gene linked to prognosis. Experiments have proven that IGF2 can promote the glycolysis pathway and the malignant biological progression of OC cells.

CONCLUSIONS

We developed two novel OC subtypes based on glycolysis score, established a stable prognostic model, and identified IGF2 as the marker gene. These insights provided a new avenue for exploring OC's molecular mechanisms and personalized treatment approaches.

Ongoing genome doubling promotes evolvability and immune dysregulation in ovarian cancer

Whole-genome doubling (WGD) is a critical driver of tumor development and is linked to drug resistance and metastasis in solid malignancies. Here, we demonstrate that WGD is an ongoing mutational process in tumor evolution. Using single-cell whole-genome sequencing, we measured and modeled how WGD events are distributed across cellular populations within tumors and associated WGD dynamics with properties of genome diversification and phenotypic consequences of innate immunity. We studied WGD evolution in 65 high-grade serous ovarian cancer (HGSOC) tissue samples from 40 patients, yielding 29,481 tumor cell genomes. We found near-ubiquitous evidence of WGD as an ongoing mutational process promoting cell-cell diversity, high rates of chromosomal missegregation, and consequent micronucleation. Using a novel mutation-based WGD timing method, doubleTime , we delineated specific modes by which WGD can drive tumor evolution: (i) unitary evolutionary origin followed by significant diversification, (ii) independent WGD events on a pre-existing background of copy number diversity, and (iii) evolutionarily late clonal expansions of WGD populations. Additionally, through integrated single-cell RNA sequencing and high-resolution immunofluorescence microscopy, we found that inflammatory signaling and cGAS-STING pathway activation result from ongoing chromosomal instability and are restricted to tumors that remain predominantly diploid. This contrasted with predominantly WGD tumors, which exhibited significant quiescent and immunosuppressive phenotypic states. Together, these findings establish WGD as an evolutionarily 'active' mutational process that promotes evolvability and dysregulated immunity in late stage ovarian cancer.

Lysine Demethylase 4A is a Centrosome Associated Protein Required for Centrosome Integrity and Genomic Stability

Centrosomes play a fundamental role in nucleating and organizing microtubules in the cell and are vital for faithful chromosome segregation and maintenance of genomic stability. Loss of structural or functional integrity of centrosomes causes genomic instability and is a driver of oncogenesis. The lysine demethylase 4A (KDM4A) is an epigenetic 'eraser' of chromatin methyl marks, which we show also localizes to the centrosome with single molecule resolution. We additionally discovered KDM4A demethylase enzymatic activity is required to maintain centrosome homeostasis, and is required for centrosome integrity, a new functionality unlinked to altered expression of genes regulating centrosome number. We find rather, that KDM4A interacts with both mother and daughter centriolar proteins to localize to the centrosome in all stages of mitosis. Loss of KDM4A results in supernumerary centrosomes and accrual of chromosome segregation errors including chromatin bridges and micronuclei, markers of genomic instability. In summary, these data highlight a novel role for an epigenetic 'eraser' regulating centrosome integrity, mitotic fidelity, and genomic stability at the centrosome.