Integrin αvß6 mediates the immune escape through regulation of PD-L1 and serves as a novel marker for immunotherapy of colon carcinoma.

The immune escape of colon cancer and its role in the response to immunotherapies such as PD-1/PD-L1 checkpoint inhibitors have long been of great interest. The positive outcomes of immunotherapy are limited by the immunosuppressive nature of the tumor microenvironment. Integrin αvß6, which can regulate the progression of colon cancer, was recently reported to be involved in the immune suppression of colon cancer. In the present study, we explored the correlation between αvß6 and PD-L1 expression by immunohistochemistry of colon cancer tissues. Then, the regulation of PD-L1 signaling by αvß6 in colon cancer cells was demonstrated. We constructed an in vivo model and performed immunophenotyping experiments to analyze further the regulation of the immune response by αvß6. The role of αvß6 in the response to anti-PD-1 therapy in colon cancer was also verified. αvß6-positive tissues exhibited increased PD-L1 expression. Inhibition of αvß6 not only downregulated constitutive PD-L1 expression but also decreased IFN-γ-induced PD-L1 expression. In addition, αvß6-induced PD-L1 expression was suppressed by the ERK inhibitor PD98059, and knockdown of the ß6-ERK2 binding site had the equivalent effect. αvß6 decreased CD8+ T cell infiltration and granzyme B expression in CD8+ T cells in colon cancer patients. Furthermore, mice engrafted with αvß6-expressing colon cancer cells exhibited an unsatisfactory response to anti-PD-1 therapy, and anti-PD-1-induced increases in CD4+ and CD8+ T cell infiltration could be inhibited by αvß6. These results indicate that αvß6 mediates immune escape in colon cancer by upregulating PD-L1 through the ERK/MAPK pathway. Moreover, αvß6 could serve as a marker for the efficacy of anti-PD-1 therapy in colon cancer.

Idiopathic calcinosis cutis of the buttocks: A case report and review of the literature.

RATIONALE: Calcinosis cutis is a rare skin disease, and idiopathic cases are rarely reported. It is characterized by the deposition of insoluble calcium salts in the skin, subcutaneous tissue, superficial muscles, and tendon sheaths. However, no abnormal changes were found in the bone. In this article, we introduce a case of idiopathic calcinosis cutis of the buttocks with a long course and large lesion area. PATIENT CONCERNS: A 51-year-old male patient was admitted to the hospital with a chief complaint of 'Due to the discovery of hard nodules with pruritus in the buttocks for 32 years. The patient was a male who was 51 years old. He has been in good health and reported no history of surgery, trauma, infection, metabolic disease, tumor, or other diseases. There was no family history. It is worth noting that the patient has the occupation of driving trucks, which keeps him sedentary. DIAGNOSES: The accurate diagnosis of calcinosis cutis was confirmed by postoperative histopathological examination with many local calcifications and multinucleated giant cells in subcutaneous tissue. INTERVENTIONS: The patient underwent skin lesion excision and autologous skin grafting under general anesthesia. A medium-thickness skin graft from the left lateral thigh was transplanted into the hip operation area, and a bolus tie-over pressure dressing was applied. After the operation, the patient received anti-infection treatment and was advised to rest in the prone position to prevent extrusion of the operation area. OUTCOMES: The postoperative recovery was good, and there was no recurrence after 4 months of follow-up. LESSONS: The incidence rate of cutaneous calcinosis is not clear. This patient had a large lesion area, long onset time, an invasion of the fat layer, and the onset site was located in the sacrococcygeal region. It is necessary to choose appropriate treatment methods.

A retrospective study of 1064-nm Q-switched Nd:YAG laser therapy for acquired bilateral nevus of Ota-like macules.

BACKGROUND: The therapeutic efficacy of laser treatments for acquired bilateral nevus of Ota-like macules (ABNOM) varies among studies, and few studies have evaluated the factors affecting therapeutic effects. AIMS: To evaluate the efficacy and safety of 1064-nm Q-switched Nd:YAG laser (QSNYL) therapy for ABNOM and to identify the factors influencing the outcome. METHODS: A total of 110 patients with ABNOM were retrospectively evaluated and received two-to-nine treatment sessions. The effects of different factors on the therapeutic effect were analyzed on the basis of the number of treatments, age at first treatment, skin type, lesion color, affected area, number of lesion sites, and presence of concomitant melasma. RESULTS: The curative effect was positively correlated with the treatment time and negatively correlated with the increasing age at first treatment (p < 0.05). The curative effect was better in patients with skin type III than those with type IV ( p < 0.05) and in patients with a lesion area of less than 10 cm2 than those with a larger affected area (p < 0.05). Additionally, the treatment effect was poorer in patients with concomitant melasma (p < 0.05). The treatment effect was not significantly correlated with the lesion color or number of affected sites (p > 0.05). Eleven patients (10%) developed postinflammatory hyperpigmentation (PIH). CONCLUSIONS: Early and repeated QSNYL therapy achieved satisfactory results for ABNOM. The risk of PIH after laser treatment is highest among patients with older age, darker lesion color, and darker skin color. For patients with ABNOM with concurrent melasma, low-energy laser therapy is recommended to reduce the risk of melasma aggravation.