Spatiotemporally resolved colorectal oncogenesis in mini-colons ex vivo.

Three-dimensional organoid culture technologies have revolutionized cancer research by allowing for more realistic and scalable reproductions of both tumour and microenvironmental structures1-3. This has enabled better modelling of low-complexity cancer cell behaviours that occur over relatively short periods of time4. However, available organoid systems do not capture the intricate evolutionary process of cancer development in terms of tissue architecture, cell diversity, homeostasis and lifespan. As a consequence, oncogenesis and tumour formation studies are not possible in vitro and instead require the extensive use of animal models, which provide limited spatiotemporal resolution of cellular dynamics and come at a considerable cost in terms of resources and animal lives. Here we developed topobiologically complex mini-colons that are able to undergo tumorigenesis ex vivo by integrating microfabrication, optogenetic and tissue engineering approaches. With this system, tumorigenic transformation can be spatiotemporally controlled by directing oncogenic activation through blue-light exposure, and emergent colon tumours can be tracked in real-time at the single-cell resolution for several weeks without breaking the culture. These induced mini-colons display rich intratumoural and intertumoural diversity and recapitulate key pathophysiological hallmarks displayed by colorectal tumours in vivo. By fine-tuning cell-intrinsic and cell-extrinsic parameters, mini-colons can be used to identify tumorigenic determinants and pharmacological opportunities. As a whole, our study paves the way for cancer initiation research outside living organisms.

Thymic epithelial organoids mediate T-cell development.

Although the advent of organoids has opened unprecedented perspectives for basic and translational research, immune system-related organoids remain largely underdeveloped. Here, we established organoids from the thymus, the lymphoid organ responsible for T-cell development. We identified conditions enabling mouse thymic epithelial progenitor cell proliferation and development into organoids with diverse cell populations and transcriptional profiles resembling in vivo thymic epithelial cells (TECs) more closely than traditional TEC cultures. In contrast to these two-dimensional cultures, thymic epithelial organoids maintained thymus functionality in vitro and mediated physiological T-cell development upon reaggregation with T-cell progenitors. The reaggregates showed in vivo-like epithelial diversity and the ability to attract T-cell progenitors. Thymic epithelial organoids are the first organoids originating from the stromal compartment of a lymphoid organ. They provide new opportunities to study TEC biology and T-cell development in vitro, paving the way for future thymic regeneration strategies in ageing or acute injuries.

Cancer-associated mutations in VAV1 trigger variegated signaling outputs and T-cell lymphomagenesis.

Mutations in VAV1, a gene that encodes a multifunctional protein important for lymphocytes, are found at different frequencies in peripheral T-cell lymphoma (PTCL), non-small cell lung cancer, and other tumors. However, their pathobiological significance remains unsettled. After cataloguing 51 cancer-associated VAV1 mutations, we show here that they can be classified in five subtypes according to functional impact on the three main VAV1 signaling branches, GEF-dependent activation of RAC1, GEF-independent adaptor-like, and tumor suppressor functions. These mutations target new and previously established regulatory layers of the protein, leading to quantitative and qualitative changes in VAV1 signaling output. We also demonstrate that the most frequent VAV1 mutant subtype drives PTCL formation in mice. This process requires the concurrent engagement of two downstream signaling branches that promote the chronic activation and transformation of follicular helper T cells. Collectively, these data reveal the genetic constraints associated with the lymphomagenic potential of VAV1 mutant subsets, similarities with other PTCL driver genes, and potential therapeutic vulnerabilities.

RNA Expression of MMP12 Is Strongly Associated with Inflammatory Bowel Disease and Is Regulated by Metabolic Pathways in RAW 264.7 Macrophages.

Macrophage metalloelastase or matrix metalloproteinase-12 (MMP12) is a macrophage-specific proteolytic enzyme involved in the physiopathology of many inflammatory diseases, including inflammatory bowel disease. Although previously published data suggested that the modulation of MMP12 in macrophages could be a determinant for the development of intestinal inflammation, scarce information is available on the mechanisms underlying the regulation of MMP12 expression in those phagocytes. Therefore, in this study, we aimed to delineate the association of MMP12 with inflammatory bowel disease and the molecular events leading to the transcriptional control of this metalloproteinase. For that, we used publicly available transcriptional data. Also, we worked with the RAW 264.7 macrophage cell line for functional experiments. Our results showed a strong association of MMP12 expression with the severity of inflammatory bowel disease and the response to relevant biological therapies. In vitro assays revealed that the inhibition of mechanistic target of rapamycin complex 1 (mTORC1) and the stimulation of the AMP-activated protein kinase (AMPK) signaling pathway potentiated the expression of Mmp12. Additionally, AMPK and mTOR required a functional downstream glycolytic pathway to fully engage with Mmp12 expression. Finally, the pharmacological inhibition of MMP12 abolished the expression of the proinflammatory cytokine Interleukin-6 (Il6) in macrophages. Overall, our findings provide a better understanding of the mechanistic regulation of MMP12 in macrophages and its relationship with inflammation.

Aryl hydrocarbon receptor controls skin homeostasis, regeneration, and hair follicle cycling by adjusting epidermal stem cell function.

Skin integrity requires constant maintenance of a quiescent, yet responsive, population of stem cells. While interfollicular epidermal progenitors control normal homeostasis, hair follicle stem cells residing within the bulge provide regenerative potential during hair cycle and in response to wounding. The aryl hydrocarbon receptor (AhR) modulates cell plasticity and differentiation and its overactivation results in severe skin lesions in humans. However, its physiological role in skin homeostasis and hair growth is unknown. Reconstitution assays grafting primary keratinocytes and dermal fibroblasts into nude mice and 3-D epidermal equivalents revealed a positive role for AhR in skin regeneration, epidermal differentiation, and stem cell maintenance. Furthermore, lack of receptor expression in AhR-/- mice delayed morphogenesis and impaired hair regrowth with a phenotype closely correlating with a reduction in suprabasal bulge stem cells (α6low CD34+ ). Moreover, RNA-microarray and RT-qPCR analyses of fluorescence-activated cell sorting (FACS)-isolated bulge stem cells revealed that AhR depletion impaired transcriptional signatures typical of both epidermal progenitors and bulge stem cells but upregulated differentiation markers likely compromising their undifferentiated phenotype. Altogether, our findings support that AhR controls skin regeneration and homeostasis by ensuring epidermal stem cell identity and highlights this receptor as potential target for the treatment of cutaneous pathologies.

High dose subcutaneous Anakinra to treat acute respiratory distress syndrome secondary to cytokine storm syndrome among severely ill COVID-19 patients.

OBJECTIVE: Severely ill COVID-19 patients may end in acute respiratory distress syndrome (ARDS) and multi-organ failure. Some of them develop a systemic hyperinflammatory state produced by the massive release of inflammatory agents, known as cytokine storm syndrome (CSS). Inhibition of IL-1 by Anakinra (ANK) is a potential life-saving therapy for severe CSS cases. We propose a rationale for the use of subcutaneous ANK and review our initial experience in a small cohort of severe COVID-19 CSS patients. METHODS: Retrospective cohort study of COVID-19 patients developing ARDS (PaO2/FiO2 <300) and exhibiting signs of hyperinflammation (ferritin >1000 ng/mL and/or d-dimers > 1.5 µg/mL, plus IL-6 < 40 mg/mL) that received ANK. For comparison, a propensity score matched historical cohort of patients treated with IL-6 inhibitor Tocilizumab (TCZ) was used. Patients had previously received combinations of azithromycin, hydroxy-chloroquine, and methyl-prednisolone. Laboratory findings, respiratory function and adverse effects were monitored. Resolution of ARDS within the first 7 days of treatment was considered a favorable outcome. RESULTS: Subcutaneous ANK (100 mg every 6 h) was given to 9 COVID-19 ARDS CSS patients (77.8% males). Median age was 62 years (range, 42 to 87). A TCZ cohort of 18 patients was selected by propensity score matching and treated with intravenous single dose of 600 mg for patients weighing >75 Kg, or 400 mg if < 75 Kg. Prior to treatment, median PaO2/FiO2 ratio of the ANK and TCZ cohorts were 193 and 249, respectively (p = 0.131). After 7 days of treatment, PaO2/FiO2 ratio improved in both groups to 279 (104-335) and 331 (140-476, p = 0.099) respectively. On day 7, there was significant reduction of ferritin (p = 0.046), CRP (p = 0.043), and IL-6 (p = 0.043) levels in the ANK cohort but only of CRP (p = 0.001) in the TCZ group. Favorable outcome was achieved in 55.6% and 88.9% of the ANK and TCZ cohorts, respectively (p = 0.281). Two patients that failed to respond to TCZ improved after ANK treatment. Aminotransferase levels significantly increased between day 1 and day 7 (p = 0.004) in the TCZ group. Mortality was the same in both groups (11%). There were not any opportunistic infection in the groups nor other adverse effects attributable to treatment. CONCLUSION: Overall, 55.6% of COVID-19 ARDS CSS patients treated with ANK exhibited favorable outcome, not inferior to a TCZ treated matched cohort. ANK may be a potential alternative to TCZ for patients with elevated aminotransferases, and may be useful in non-responders to TCZ.

Nidogen-2: Location and expression during corneal wound healing.

Nidogen-2 is a basement membrane (BM) glycoprotein that could be a key to understanding why defects in BM regeneration occur after severe trauma to the cornea. We monitored the location and expression of nidogen-2 during corneal repair after alkali burn in rabbits. In rabbits that received both general and ocular topical anaesthesia, the central cornea of the left eye was burned by placing an 8-mm diameter filter paper soaked in 0.5 N NaOH for 60 s. Right corneas were used as controls. The eyes were evaluated at 2, 7, 15, and 30 days after burning and analysed by immunohistochemistry for nidogen-2 and α-smooth muscle actin, a myofibroblast marker. Nidogen-2 mRNA expression levels were determined by quantitative real-time polymerase chain reaction. In control corneas, nidogen-2-positive cells were in all epithelial layers, the endothelium, and the anterior and posterior stromal regions. At Day 2 after the alkali burn, the wound area epithelium and the peripheral epithelium were made up of only 1 to 2 cell layers, all of them nidogen-2 positive. At Day 7 in the wound area, the epithelium consisted of two cell layers, and the basally located cells were mostly nidogen-2 positive. The greatest change was observed at Day 30. At this time, the ulcer prevalence in the alkali-burned corneas was approximately 50% and the central epithelial defects remained. In unepithelialized corneas, frequent epithelial detachments were present, in which almost of the epithelial cells were nidogen-2 negative. The injured stroma was repopulated by activated stromal cells that synthesized nidogen-2. The nidogen-2 was retained in the newly secreted, but disordered, matrix produced mainly by the myofibroblasts localized in the stroma at 7, 15, and 30 days after burning. Thus, even though nidogen-2 was present, it was unable to contribute to the effective regeneration of the BM.

Dynamic changes of the extracellular matrix during corneal wound healing.

The extracellular matrix (ECM) confers transparency to the cornea because of the precise organization of collagen fibrils and a wide variety of proteoglycans. We monitored the corneal wound healing process after alkali burns in rabbits. We analyzed the location and expression of collagens and proteoglycans, the clinical impact, and the recovery of optical transparency. After the animals received both general and ocular topical anesthesia, the central cornea of the left eye was burned by placing an 8-mm diameter filter paper soaked in 0.5 N NaOH for 60 s. The eyes were evaluated under a surgical microscope at 1, 3, and 6 months after burning. At each time point, the clinical conditions of the burned and control corneas were observed. The arrangement of collagen fibers in the corneal stroma was visualized by Picrosirius-red staining, Gomori's silver impregnation and transmission electronic microscopy. Corneal light transmittance was also measured. Myofibroblasts presence was analyzed by immunohistochemistry. mRNA expression levels of collagen types I and III, lumican, decorin, keratocan and alpha-smooth muscle actin were determined by quantitative real-time polymerase chain reaction. One month after alkali burn, the ECM was disorganized and filled with lacunae containing different types of cells and collagen type III fibers in the wound area. Corneal opacities were present with attendant loss of light transmittance. Collagen and proteoglycan mRNA expression levels were up-regulated. After three months, wound healing progress was indicated by reduced corneal opacity, increased light transmittance, reorganization of collagen fibers and only collagen type I expression levels were at control levels. After six months, the wound area ECM morphology was similar to controls, but transmittance values remained low, denoting incomplete restoration of the stromal architecture. This multidisciplinary study of the stromal wound healing process revealed changes in corneal transmittance, collagen organization, myofibroblasts presence and ECM composition at 1, 3, and 6 months after alkali burning. Documenting wound resolution during the six-month period provided reliable information that can be used to test new therapies.

Pan-valvulitis in Children With Kawasaki Disease: A Case Report and Review of the Literature.

We present a rare case of pan-valvular involvement in a 5-month-old female with Kawasaki disease shock syndrome despite early treatment with intravenous immunoglobulin and corticosteroids. She experienced a favorable outcome after the addition of infliximab, which was guided based on clinical, laboratory and echocardiogram findings, rather than recrudescence of fever, the most common indicator of intravenous immunoglobulin resistance.

A scoping review on upper extremity prostheses: Satisfaction, barriers, and their implications in resource-limited countries.

The rates of prosthetic abandonment are not extensively understood especially in resource-limited countries. A scoping review was conducted to examine the literature on the satisfaction with and barriers to using specifically upper limb prostheses. A systematic search of the literature identified 425 studies. After reviewing the articles using predetermined inclusion and exclusion criteria, 7 cross-sectional studies were included in the final review. Barriers to the use of upper limb prostheses include the characteristics of the prosthesis (type, comfort, weight, functionality, price, and availability) and individual patient factors (recent prosthetic user, level of amputation, congenital and accidental limb loss, pain, and duration between amputation and prosthetic fitting). Considering tailored prosthetic design and funding may result in improved prosthetic adherence.

Patient-derived mini-colons enable long-term modeling of tumor-microenvironment complexity.

Existing organoid models fall short of fully capturing the complexity of cancer because they lack sufficient multicellular diversity, tissue-level organization, biological durability and experimental flexibility. Thus, many multifactorial cancer processes, especially those involving the tumor microenvironment, are difficult to study ex vivo. To overcome these limitations, we herein implemented tissue-engineering and microfabrication technologies to develop topobiologically complex, patient-specific cancer avatars. Focusing on colorectal cancer, we generated miniature tissues consisting of long-lived gut-shaped human colon epithelia ('mini-colons') that stably integrate cancer cells and their native tumor microenvironment in a format optimized for real-time, high-resolution evaluation of cellular dynamics. We demonstrate the potential of this system through several applications: a comprehensive evaluation of drug effectivity, toxicity and resistance in anticancer therapies; the discovery of a mechanism triggered by cancer-associated fibroblasts that drives cancer invasion; and the identification of immunomodulatory interactions among different components of the tumor microenvironment. Similar approaches should be feasible for diverse tumor types.

Nanoplasmonic Single-Tumoroid Microarray for Real-Time Secretion Analysis.

Organoid tumor models have emerged as a powerful tool in the fields of biology and medicine as such 3D structures grown from tumor cells recapitulate better tumor characteristics, making these tumoroids unique for personalized cancer research. Assessment of their functional behavior, particularly protein secretion, is of significant importance to provide comprehensive insights. Here, a label-free spectroscopic imaging platform is presented with advanced integrated optofluidic nanoplasmonic biosensor that enables real-time secretion analysis from single tumoroids. A novel two-layer microwell design isolates tumoroids, preventing signal interference, and the microarray configuration allows concurrent analysis of multiple tumoroids. The dual imaging capability combining time-lapse plasmonic spectroscopy and bright-field microscopy facilitates simultaneous observation of secretion dynamics, motility, and morphology. The integrated biosensor is demonstrated with colorectal tumoroids derived from both cell lines and patient samples to investigate their vascular endothelial growth factor A (VEGF-A) secretion, growth, and movement under various conditions, including normoxia, hypoxia, and drug treatment. This platform, by offering a label-free approach with nanophotonics to monitor tumoroids, can pave the way for new applications in fundamental biological studies, drug screening, and the development of therapies.

The mevalonate pathway contributes to breast primary tumorigenesis and lung metastasis.

The mevalonate pathway plays an important role in breast cancer and other tumor types. However, many issues remain obscure as yet regarding its mechanism of regulation and action. In the present study, we report that the expression of mevalonate pathway enzymes is mediated by the RHO guanosine nucleotide exchange factors VAV2 and VAV3 in a RAC1- and sterol regulatory element-binding factor (SREBF)-dependent manner in breast cancer cells. Furthermore, in vivo tumorigenesis experiments indicated that the two most upstream steps of this metabolic pathway [3-hydroxy-3-methylglutaryl-coenzyme A synthase 1 (HMGCS1) and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR)] are important for primary tumorigenesis, angiogenesis, and cell survival in breast cancer cells. HMGCR, but not HMGCS1, is also important for the extravasation and subsequent fitness of breast cancer cells in the lung parenchyma. Genome-wide expression analyses revealed that HMGCR influences the expression of gene signatures linked to proliferation, metabolism, and immune responses. The HMGCR-regulated gene signature predicts long-term tumor recurrence but not metastasis in cohorts of nonsegregated and chemotherapy-resistant breast cancer patients. These results reveal a hitherto unknown, VAV-catalysis-dependent mechanism involved in the regulation of the mevalonate pathway in breast cancer cells. They also identify specific mevalonate-pathway-dependent processes that contribute to the malignant features of breast cancer cells.

VAV2 orchestrates the interplay between regenerative proliferation and ribogenesis in both keratinocytes and oral squamous cell carcinoma.

VAV2 is an activator of RHO GTPases that promotes and maintains regenerative proliferation-like states in normal keratinocytes and oral squamous cell carcinoma (OSCC) cells. Here, we demonstrate that VAV2 also regulates ribosome biogenesis in those cells, a program associated with poor prognosis of human papilloma virus-negative (HPV-) OSCC patients. Mechanistically, VAV2 regulates this process in a catalysis-dependent manner using a conserved pathway comprising the RAC1 and RHOA GTPases, the PAK and ROCK family kinases, and the c-MYC and YAP/TAZ transcription factors. This pathway directly promotes RNA polymerase I activity and synthesis of 47S pre-rRNA precursors. This process is further consolidated by the upregulation of ribosome biogenesis factors and the acquisition of the YAP/TAZ-dependent undifferentiated cell state. Finally, we show that RNA polymerase I is a therapeutic Achilles' heel for both keratinocytes and OSCC patient-derived cells endowed with high VAV2 catalytic activity. Collectively, these findings highlight the therapeutic potential of modulating VAV2 and the ribosome biogenesis pathways in both preneoplastic and late progression stages of OSCC.

Probing the killing potency of tumor-infiltrating lymphocytes on microarrayed colorectal cancer tumoroids.

Immunotherapy has emerged as a new standard of care for certain cancer patients with specific cellular and molecular makeups. However, there is still an unmet need for ex vivo models able to readily assess the effectiveness of immunotherapeutic treatments in a high-throughput and patient-specific manner. To address this issue, we have developed a microarrayed system of patient-derived tumoroids with recreated immune microenvironments that are optimized for the high-content evaluation of tumor-infiltrating lymphocyte functionality. Here we show that this system offers unprecedented opportunities to evaluate tumor immunogenicity, characterize the response to immunomodulators, and explore novel approaches for personalized immuno-oncology.

The Relationship between Selective Digestive Decontamination and Nosocomial Infections in Patients Receiving Continuous Renal Replacement Therapy in ICUs: A Multicenter Study.

Background: Nosocomial infections are a worldwide healthcare issue, especially in intensive care units (ICUs), and they had a prevalence of 21.1% in 2023 in Spain. Numerous predisposing risk factors have been identified, with the most relevant being invasive techniques, including renal replacement therapies (RRTs). Several outstanding strategies have been published that prevent or reduce their incidence, including the nationwide ZERO in Spain, which consists of structured guidelines to be implemented to tackle this problem. One of these strategies, which is defined as 'highly recommended' in these projects, is selective digestive decontamination (SDD). The main aim of this study is to compare the incidences of ICU-acquired infections, including those due to multidrug-resistant bacteria (MDRB), in two cohorts of RRT with or without SDD. Methods: We conducted a multicenter, prospective, observational study at two tertiary hospitals in Spain. In total, 140 patients treated with RRT were recruited based on their exposure to SDD. Surveillance microbiological samples and nosocomial infection risk factors were obtained. Infection rates per 1000 days of exposure and the MDRB incidence density ratio were determined. Results: SDD statistically significantly reduced RRT-associated nosocomial infections (OR: 0.10, 95% CI: (0.04-0.26)) and the MDRB incidence density ratio (IDR: 0.156, 95% CI = 0.048-0.506). However, mechanical ventilation (OR: 7.91, 95% CI: (2.54-24.66)) and peripheral vascular disease (OR: 3.17, 95% CI: (1.33-7.56)) were significantly associated with increases in infections. Conclusions: Our results favor the use of SDD in ICU patients with renal failure undergoing CRRT as a tool for infection control.

Access to surgical treatment for hepatopancreaticobiliary cancer in the Philippines.

Hepatopancreaticobiliary cancers are among the most diagnosed cancers in the world. However, although high-income countries have the highest incidence rates, low- and middle-income countries have the highest mortality rates. In this article, we describe the geographic distribution of board-certified hepatopancreaticobiliary surgeons who provide surgical management for patients with these diseases in the Philippines. We draw attention to the geographic disparities in the distribution of these surgeons and the other factors that contribute to the lack of access. Lastly, we suggest ways forward.