THBS1-producing tumor-infiltrating monocyte-like cells contribute to immunosuppression and metastasis in colorectal cancer.

Mesenchymal activation, characterized by dense stromal infiltration of immune and mesenchymal cells, fuels the aggressiveness of colorectal cancers (CRC), driving progression and metastasis. Targetable molecules in the tumor microenvironment (TME) need to be identified to improve the outcome in CRC patients with this aggressive phenotype. This study reports a positive link between high thrombospondin-1 (THBS1) expression and mesenchymal characteristics, immunosuppression, and unfavorable CRC prognosis. Bone marrow-derived monocyte-like cells recruited by CXCL12 are the primary source of THBS1, which contributes to the development of metastasis by inducing cytotoxic T-cell exhaustion and impairing vascularization. Furthermore, in orthotopically generated CRC models in male mice, THBS1 loss in the TME renders tumors partially sensitive to immune checkpoint inhibitors and anti-cancer drugs. Our study establishes THBS1 as a potential biomarker for identifying mesenchymal CRC and as a critical suppressor of antitumor immunity that contributes to the progression of this malignancy with a poor prognosis.

Summary of the current status of clinically diagnosed cases of Schnitzler syndrome in Japan.

BACKGROUND: Schnitzler syndrome is a rare disorder with chronic urticaria, and there is no report summarizing the current status in Japan. METHODS: A nationwide survey of major dermatology departments in Japan was conducted in 2019. We further performed a systematic search of PubMed and Ichushi-Web, using the keywords "Schnitzler syndrome" and "Japan" then contacted the corresponding authors or physicians for further information. RESULTS: Excluding duplicates, a total of 36 clinically diagnosed cases were identified from 1994 through the spring of 2022, with a male to female ratio of 1:1. The median age of onset was 56.5 years. It took 3.3 years from the first symptom, mostly urticaria, to reach the final diagnosis. The current status of 30 cases was ascertained; two patients developed B-cell lymphoma. SchS treatment was generally effective with high doses of corticosteroids, but symptoms sometimes recurred after tapering. Colchicine was administered in 17 cases and was effective in 8, but showed no effect in the others. Tocilizumab, used in six cases, improved laboratory abnormalities and symptoms, but lost its efficacy after several years. Rituximab, used in five cases, was effective in reducing serum IgM levels or lymphoma mass, but not in inflammatory symptoms. Four cases were treated with IL-1 targeting therapy, either anakinra or canakinumab, and achieved complete remission, except one case with diffuse large B-cell lymphoma. CONCLUSIONS: Since Schnitzler syndrome is a rare disease, the continuous collection and long-term follow-up of clinical information is essential for its appropriate treatment and further understanding of its pathophysiology.

Giant Pilomatrical Tumor With Broad Epidermal Components: An Example of Histological Diversity and a Potential Diagnostic Pitfall of Tumors With Pilomatrical Differentiation.

ABSTRACT: The diagnosis of pilomatricoma, the most common matrical tumor, is generally straightforward; however, it exhibits diverse histology associated with various morphological stages and several clinical variants, and matrical differentiation can occur in various neoplastic diseases. A 56-year-old man was admitted to our hospital to resect an 11.0-cm skin tumor on his right shoulder. Because of its large size and surface irregularities, including multiple erosions and ulcers, cutaneous malignancies were clinically suspected. Histologically, the tumor formed numerous nodules with marked matrical differentiation in the superficial to deep dermis. Although the tumor was macroscopically asymmetrical and irregular, each nodule was microscopically round-shaped and consisted of basaloid cells without marked atypia, atypical mitoses, or lymphovascular invasion. Immunohistochemically, the tumor cells were positive for beta-catenin, LEF-1, and PHLDA-1, consistent with their pilomatrical differentiation. We diagnosed the case as a giant pilomatrical tumor with uncertain malignant potential, considering its "contradictory" features, namely, the worrisome histoarchitecture, such as the asymmetrical silhouette, but bland-looking cytological appearance. Unlike typical pilomatrical tumors, this tumor contained numerous epidermal components with features similar to those of the dermal components, resulting in a unique macroscopic and histological appearance. Our case broadens the known histological diversity of pilomatrical tumors.

Association of occupational direct radiation exposure to the hands with longitudinal melanonychia and hand eczema in spine surgeons: a survey by the society for minimally invasive spinal treatment (MIST).

PURPOSE: To investigate the association between occupational direct radiation exposure to the hands and longitudinal melanonychia (LM) and hand eczema in spine surgeons. METHODS: A web-based questionnaire survey of the Society for Minimally Invasive Spinal Treatment (MIST) in Japan was conducted. The proportion of LM and hand eczema in hands with high and low-radiation exposure was compared using Fisher's exact test. The odds ratios (ORs) and their 95% confidence intervals (CIs) for the prevalence of LM and hand eczema in the high-radiation exposure hands were calculated using generalized estimating equations for logistic regression as control for the correlation of observations among the same individuals and possible confounders. RESULTS: Among 324 members of the society, responses were received from 229 members (70.7%). A total of 454 hands from 227 participants were analysed. The prevalence of LM and hand eczema was 43% and 29%, respectively. In a hand-by-hand comparison, more hands had LM in the high-radiation exposure group than the low-radiation exposure group (90 [40%] vs. 39 [17%], respectively, p < 0.001). A similar trend was observed for hand eczema (63 [28%] vs. 33 [15%], respectively, p = 0.001). The adjusted OR for high-radiation exposure hands was 3.18 (95% CI: 2.24-4.52). Consistent results were obtained for hand eczema, with an adjusted OR of 2.26 (95% CI: 1.67-3.06). CONCLUSION: The present study suggests that direct radiation exposure to physician's hands is associated with LM and hand eczema. Those with LM and radially biased hand eczema may have had high direct radiation exposure.

Refractory serum immunoglobulin M elevation during anti-interleukin (IL)-1- or IL-6-targeted treatment in four patients with Schnitzler syndrome.

Schnitzler syndrome is characterized by chronic urticarial rash, neutrophilic dermal infiltrate, recurrent fever, bone pain, elevated C-reactive protein, and neutrophilic leukocytosis. The pathophysiology of Schnitzler syndrome is unknown, but it is considered to be an acquired form of an autoinflammatory disease because of the resemblance to clinical phenotypes of cryopyrin-associated periodic syndrome, in which a gain-of-function mutation in NLRP3 causes overexpression of interleukin (IL)-1ß. Schnitzler syndrome is generally accompanied by a monoclonal immunoglobulin (Ig)M gammopathy with a long-term risk of lymphoproliferation that is possibly associated with an MYD88 mutation. Herein, we present the following four patients with Schnitzler syndrome: a 63-year-old woman; a 65-year-old man; a 43-year-old woman; and a 63-year-old woman. Each patient fulfilled the Strasbourg diagnostic criteria, but none of the patients had any mutation in NLRP3 or MYD88 detected in their peripheral blood. Although approved treatment options for Schnitzler syndrome are lacking, our patients were treated with IL-1-targeted therapy (anakinra or canakinumab) or anti-IL-6 (tocilizumab). The acute inflammatory clinical manifestations improved completely with canakinumab and partially with anakinra and tocilizumab, but the serum IgM levels were gradually increased in all patients, even during treatment. To determine whether treatment with anti-IL-1ß or IL-6 prevents conversion to a hematopoietic disorder, further collection of cases and long-term follow-up will be needed.

Extraocular sebaceous carcinoma accompanied by invasive squamous cell carcinoma: The first case report and consideration of histogenesis.

A 61-year-old man presented with a dome-shaped nodule, 1.2 cm in size, with a central crater covered by keratinous material near the left lateral malleolus. Histological findings demonstrated a basophilic circular cone in the center, surrounded and sharply demarcated by a broad eosinophilic area. The central conical mass was composed mainly of atypical basaloid cells intermingled with scattered atypical sebaceous cells with scalloped nuclei and microvesicular cytoplasms, suggesting sebaceous carcinoma. The peripheral area consisted of atypical keratinizing squamoid cells without sebaceous cells, suggesting invasive squamous cell carcinoma. Atypical sebaceous cells were positive for adipophilin. Atypical basaloid cells were positive for 34ßE12 and CAM5.2. Peripheral squamoid cells were positive for 34ßB4 and 34ßE12 throughout, and were positive for LHP1 in the superficial layer. We herein describe the first case of extraocular sebaceous carcinoma accompanied by invasive squamous cell carcinoma, which might have arisen from biphasic differentiation of cancer stem cells.

Spindle cell squamous cell carcinoma arising in Bowen's disease: Case report and review of the published work.

A 79-year-old Japanese woman presented with an ulcerated, brown-red nodule in the center of a sharply demarcated, tan-brown plaque situated on the left side of her right breast. Histologically, the plaque demonstrated an acanthosis with an intraepidermal epithelioma of Borst-Jadassohn. Small oval nests of bland-appearing basophilic cells in the periphery gradually enlarged into nests of various sizes and irregular shapes, composed of densely cohesive, atypical basophilic cells above the central nodule. The atypical keratinocytes shifted to atypical spindle cells beneath the acanthotic epidermis, penetrating deep into the subcutaneous tissue. In addition to vimentin and p63, the spindle cells were positive for several cytokeratin (CK) markers, including AE1/AE3, 34ßE12 and CK5/6, which showed more intense signals closer to the epidermis. Basophilic cells in the clonal nests were positive for p63, AE1/AE3, 34ßE12 and CK5/6. The MIB-1 index was estimated at approximately 40-50% in both the bland-appearing and the atypical basophilic cells. We describe the first case of spindle cell squamous cell carcinoma arising in an intraepidermal epithelioma expressed by clonal Bowen's disease, which was difficult to differentiate from clonal seborrheic keratosis.

Palmoplantar keratosis in oculodentodigital dysplasia with a GJA1 point mutation out of the C-terminal region of connexin 43.

Gap junction proteins are composed of 21 genes of the connexin (Cx) family. They play important roles in cell-cell contact by exchange of small molecules through hemichannels. Hence, mutations of Cx family genes affect various tissues of a body. The mutation of the GJA1 gene, which codes Cx43, causes oculodentodigital dysplasia (ODDD), commonly in an autosomal dominant manner with phenotypic variability. It has been believed that gene mutations causing truncation of the Cx43 C-terminus is necessary and sufficient for palmoplantar keratosis (PPK) development in ODDD patients. Here, we report a case of an ODDD patient developing PPK with a GJA1 gene mutation (c.412G>A/p.Gly138Ser), which was previously reported in a case of ODDD without PPK and expected not to result in C-terminal truncation of Cx43. This case suggests not only C-terminal truncation, but also that a point mutation in the cytoplasmic region of Cx43 can cause PPK in ODDD patients.

Differential and common DNA repair pathways for topoisomerase I- and II-targeted drugs in a genetic DT40 repair cell screen panel.

Clinical topoisomerase I (Top1) and II (Top2) inhibitors trap topoisomerases on DNA, thereby inducing protein-linked DNA breaks. Cancer cells resist the drugs by removing topoisomerase-DNA complexes, and repairing the drug-induced DNA double-strand breaks (DSB) by homologous recombination and nonhomologous end joining (NHEJ). Because numerous enzymes and cofactors are involved in the removal of the topoisomerase-DNA complexes and DSB repair, it has been challenging to comprehensively analyze the relative contribution of multiple genetic pathways in vertebrate cells. Comprehending the relative contribution of individual repair factors would give insights into the lesions induced by the inhibitors and genetic determinants of response. Ultimately, this information would be useful to target specific pathways to augment the therapeutic activity of topoisomerase inhibitors. To this end, we put together 48 isogenic DT40 mutant cells deficient in DNA repair and generated one cell line deficient in autophagy (ATG5). Sensitivity profiles were established for three clinically relevant Top1 inhibitors (camptothecin and the indenoisoquinolines LMP400 and LMP776) and three Top2 inhibitors (etoposide, doxorubicin, and ICRF-193). Highly significant correlations were found among Top1 inhibitors as well as Top2 inhibitors, whereas the profiles of Top1 inhibitors were different from those of Top2 inhibitors. Most distinct repair pathways between Top1 and Top2 inhibitors include NHEJ, TDP1, TDP2, PARP1, and Fanconi Anemia genes, whereas homologous recombination seems relevant especially for Top1 and, to a lesser extent, for Top2 inhibitors. We also found and discuss differential pathways among Top1 inhibitors and Top2 inhibitors.

GEMIN2 promotes accumulation of RAD51 at double-strand breaks in homologous recombination.

RAD51 is a key factor in homologous recombination (HR) and plays an essential role in cellular proliferation by repairing DNA damage during replication. The assembly of RAD51 at DNA damage is strictly controlled by RAD51 mediators, including BRCA1 and BRCA2. We found that human RAD51 directly binds GEMIN2/SIP1, a protein involved in spliceosome biogenesis. Biochemical analyses indicated that GEMIN2 enhances the RAD51-DNA complex formation by inhibiting RAD51 dissociation from DNA, and thereby stimulates RAD51-mediated homologous pairing. GEMIN2 also enhanced the RAD51-mediated strand exchange, when RPA was pre-bound to ssDNA before the addition of RAD51. To analyze the function of GEMIN2, we depleted GEMIN2 in the chicken DT40 line and in human cells. The loss of GEMIN2 reduced HR efficiency and resulted in a significant decrease in the number of RAD51 subnuclear foci, as observed in cells deficient in BRCA1 and BRCA2. These observations and our biochemical analyses reveal that GEMIN2 regulates HR as a novel RAD51 mediator.

Collaborative action of Brca1 and CtIP in elimination of covalent modifications from double-strand breaks to facilitate subsequent break repair.

Topoisomerase inhibitors such as camptothecin and etoposide are used as anti-cancer drugs and induce double-strand breaks (DSBs) in genomic DNA in cycling cells. These DSBs are often covalently bound with polypeptides at the 3' and 5' ends. Such modifications must be eliminated before DSB repair can take place, but it remains elusive which nucleases are involved in this process. Previous studies show that CtIP plays a critical role in the generation of 3' single-strand overhang at "clean" DSBs, thus initiating homologous recombination (HR)-dependent DSB repair. To analyze the function of CtIP in detail, we conditionally disrupted the CtIP gene in the chicken DT40 cell line. We found that CtIP is essential for cellular proliferation as well as for the formation of 3' single-strand overhang, similar to what is observed in DT40 cells deficient in the Mre11/Rad50/Nbs1 complex. We also generated DT40 cell line harboring CtIP with an alanine substitution at residue Ser332, which is required for interaction with BRCA1. Although the resulting CtIP(S332A/-/-) cells exhibited accumulation of RPA and Rad51 upon DNA damage, and were proficient in HR, they showed a marked hypersensitivity to camptothecin and etoposide in comparison with CtIP(+/-/-) cells. Finally, CtIP(S332A/-/-)BRCA1(-/-) and CtIP(+/-/-)BRCA1(-/-) showed similar sensitivities to these reagents. Taken together, our data indicate that, in addition to its function in HR, CtIP plays a role in cellular tolerance to topoisomerase inhibitors. We propose that the BRCA1-CtIP complex plays a role in the nuclease-mediated elimination of oligonucleotides covalently bound to polypeptides from DSBs, thereby facilitating subsequent DSB repair.