Caveolin-1 differentially regulates the transforming growth factor-ß and epidermal growth factor signaling pathways in MDCK cells.

Caveolin-1 is critical for interacting with the TGF-ß receptor (TGFßR) and EGF receptor (EGFR) signaling, often observed in advanced cancers and tissue fibrosis. However, the mechanism underlying caveolin-1-mediated transactivation of TGFßR and EGFR signaling remains unclear. Therefore, we sought to determine whether caveolin-1 is involved in canonical and non-canonical TGFßR and EGFR signaling transactivation in this study. Methyl-ß-cyclodextrin (MßCD) was used to disrupt the cholesterol-containing membranes domains, and the caveolin-1 scaffolding domain (CSD) peptide was used to mimic the CSD of caveolin-1. Additionally, we transfected the Madin-Darby canine kidney cells with wild-type or phosphorylation-defective caveolin-1. We discovered that tyrosine 14 of caveolin-1 was critical for the negative regulation of TGFßR and EGFR canonical signaling. On the contrary, caveolin-1 inhibited TGF-ß1-induced ERK2 activation independent of tyrosine 14 phosphorylation. Although EGF failed to induce Smad3 phosphorylation in caveolin-1 knockdown cells, it activated Smad3 upon MßCD co-treatment, indicating that caveolin-1 indirectly regulated the non-canonical pathway of EGF. In conclusion, caveolin-1 differentially modulates TGFßR and EGFR signaling. Thus, targeting caveolin-1 is a potential strategy for treating diseases involving TGF-ß1 and EGF signaling.

Recurrent Marginal Zone Lymphoma with Bone Marrow Involvement Detected by ¹8F-FDG PET/CT and Biopsy: A Diagnostic Challenge.

BACKGROUND Marginal zone lymphoma is a low-grade, B-cell, non-Hodgkin lymphoma. Bone marrow involvement (BMI) of leukemia or lymphoma can usually be displayed in fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (¹8F-FDG PET/CT) with high standardized uptake values (SUV), while diffuse homogeneous ¹8F-FDG bone marrow uptake (BMU) in PET/CT primarily reflects hyperplastic bone marrow status. This report is of a 74-year-old man presenting with anemia and a diagnosis of recurrent marginal zone lymphoma with bone marrow involvement identified with 18F-FDG PET/CT imaging and biopsy. CASE REPORT A 64-year-old man with severe anemia and body weight loss of 7 kg in 1 month was diagnosed with marginal zone lymphoma, stage III, in July 2011. He went into complete remission in April 2012 after 6 cycles of chemotherapy, with Hb restored. Anemia and diffuse homogeneous ¹8F-FDG BMU in PET/CT were then noted during a routine check-up in October 2021, and recurrent disease was established through positive biopsy of subcutaneous nodules and bone marrow. Subsequent complete remission after 6 cycles of combination therapy was validated with pathologically negative BMI, the resolution of the slightly enhanced ¹8F-FDG BMU in PET/CT, and restored hemoglobin. CONCLUSIONS This report has highlighted the importance of follow-up for patients with lymphoma and supports the diagnostic role of ¹8F-FDG PET/CT imaging and the pathological verification in identifying malignant involvement in bone marrow.

Depletion of intracellular Ca2+ induces FOXM1 SUMOylation and accumulation on the inner nuclear membrane and accelerates G2/M cell cycle transition.

Intracellular calcium (Ca2+) has been reported to regulate transcription factor activity and cancer development, but how it affects the function of Forkhead box protein M1 (FOXM1), a crucial transcription factor and key oncogene participating in tumorigenesis, remains unclear. Here, we investigated the regulatory role of Ca2+ on FOXM1 and found that Ca2+ depletion caused the distribution of FOXM1 to aggregate on the nuclear envelope, which was also observed in many cell lines. Further experiments revealed that sequestrated FOXM1 colocalized with lamin B in the inner nuclear membrane (INM) and was affected by the activity of nuclear export protein exportin 1 (XPO1). To investigate how intracellular Ca2+ affects FOXM1, we found that among the posttranscriptional modifications, only SUMOylation of FOXM1 showed a pronounced increase under reduced Ca2+, and suppressed SUMOylation rescued FOXM1 sequestration. In addition, Ca2+-dependent SUMOylated FOXM1 appeared to enhance the G2/M transition of the cell cycle and decrease cell apoptosis. In conclusion, our findings provide a molecular basis for the relationship between Ca2+ signaling and FOXM1 regulation, and we look to elucidate Ca2+-dependent FOXM1 SUMOylation-related biological functions in the future.

STIM1 Controls the Focal Adhesion Dynamics and Cell Migration by Regulating SOCE in Osteosarcoma.

The dysregulation of store-operated Ca2+ entry (SOCE) promotes cancer progression by changing Ca2+ levels in the cytosol or endoplasmic reticulum. Stromal interaction molecule 1 (STIM1), a component of SOCE, is upregulated in several types of cancer and responsible for cancer cell migration, invasion, and metastasis. To explore the impact of STIM1-mediated SOCE on the turnover of focal adhesion (FA) and cell migration, we overexpressed the wild-type and constitutively active or dominant negative variants of STIM1 in an osteosarcoma cell line. In this study, we hypothesized that STIM1-mediated Ca2+ elevation may increase cell migration. We found that constitutively active STIM1 dramatically increased the Ca2+ influx, calpain activity, and turnover of FA proteins, such as the focal adhesion kinase (FAK), paxillin, and vinculin, which impede the cell migration ability. In contrast, dominant negative STIM1 decreased the turnover of FA proteins as its wild-type variant compared to the cells without STIM1 overexpression while promoting cell migration. These unexpected results suggest that cancer cells need an appropriate amount of Ca2+ to control the assembly and disassembly of focal adhesions by regulating calpain activity. On the other hand, overloaded Ca2+ results in excessive calpain activity, which is not beneficial for cancer metastasis.

A noteworthy treatment of metastatic small-cell lung cancer with afatinib, followed by subsequent development of rare metastatic lesions in the ascending and sigmoid colon.

BACKGROUND: Small-cell lung cancer (SCLC) represents a group of highly fatal diseases with a tendency toward fast growth, early metastasis, and easy development of chemotherapy resistance. In the past 30 years, few advances have been made in the systemic treatment of SCLC, and cisplatin/etoposide has remained the standard of care for limited-stage SCLC and, in combination with radiotherapy, extensive-stage SCLC. The preferred metastatic sites of SCLC include the brain, liver, adrenal glands, bone, and bone marrow. However, bowel metastasis caused by SCLC is extremely rarely proved in patients while they are still alive (although autopsy studies suggest that silent metastases to the bowel are more common), and the standard treatment for bowel metastasis has never been reported. The mean time between the identification of gastrointestinal metastasis and mortality in patients with lung cancer is 100.6 days, with a range of 21-145 days. CASE: We report the case of a patient with extensive SCLC (including brain metastasis), in which exon 19 deletion of epidermal growth factor receptor (EGFR) was detected. She initially refused chemotherapy and cranial radiotherapy and instead only agreed to oral target therapy. The second-generation EGFR-tyrosine kinase inhibitor (TKI), afatinib, was administered to the patient, and partial remission, including smaller metastatic brain tumors, was noted. Even though the subsequent development of rare metastatic lesions in the ascending and sigmoid colon was proved by colonoscopic biopsies, the prolonged overall survival (400 days) without standard treatment was marked in this case. CONCLUSION: The patient with extensive metastasis of SCLC did not receive standard systemic chemotherapy. Instead, she initially received second-generation EGFR-TKI afatinib alone and later on whole brain radiotherapy as well (3 weeks before she expired). The prolonged overall survival of 400 days was marked and is worthy of sharing and further investigation.

SOX11 is useful in differentiating cyclin D1-positive diffuse large B-cell lymphoma from mantle cell lymphoma.

AIMS: To characterize the frequency and clinicopathological features of cyclin D1-positive diffuse large B-cell lymphoma (DLBCL) and the usefulness of SOX11 in the differential diagnosis from mantle cell lymphoma (MCL). METHODS AND RESULTS: We retrospectively stained 206 consecutive DLBCLs for cyclin D1, and identified three (1.5%) positive cases, comprising two in the elderly with necrosis, and a third with a starry-sky pattern. All three cases shared the same non-germinal centre B-cell (non-GCB) phenotype [CD5-/CD10-/bcl-6+/MUM1+/SOX11-], Epstein-Barr virus (EBV) negativity, and absence of CCND1 aberrations by fluorescence in-situ hybridization. The third case showed both BCL6 and MYC rearrangements: a double-hit lymphoma. In the same period there were 22 MCLs, all expressing cyclin D1, with 89% cases expressing SOX11, a frequency that is statistically different from cyclin D1-positive DLBCL. Notably, we identified a pleomorphic MCL initially misdiagnosed as DLBCL. A separate cohort of 98 DLBCL cases was negative for SOX11, with only one case expressing cyclin D1 with a GCB phenotype (CD10+/bcl-6+/MUM1-). The two patients with tumour necrosis rapidly died of disease. The other two were in complete remission after immunochemotherapy. CONCLUSION: Cyclin D1-positive DLBCLs are rare, and they are negative for SOX11 or CCND1 aberration. SOX11 is useful in differentiating cyclin D1-positive DLBCL from MCL.

Modified, weekly dosing with docetaxel and cisplatin as first-line therapy in advanced non-small cell lung cancer.

BACKGROUND: Platinum-based combination chemotherapy regimens provide modest improvement in both survival and quality of life for patients with non-small cell lung cancers and docetaxel is the first agent approved for both first- and second-line treatment in patients with advanced disease. However, the regimens are associated with adverse effects. METHODS: We used a modified, shortened regimen with only 2 consecutive weekly infusions of docetaxel followed by rest for 1 week, and evaluated the efficacy and toxicity profiles in patients undergoing treatment for non-small cell lung cancers. Thirty-five patients (19 men, 16 women) with advanced non-small cell lung cancers received docetaxel (35 mg/m2 i.v. infusion on days 1 and 8) with cisplatin (60 mg/m2 i.v. infusion on day 8) in 126 cycles. RESULTS: Two of the 35 patients achieved complete response (5.7%), while 16 patients achieved partial response (45.7%). The overall response rate was 51.4% and median overall survival was 10.6 months. The toxicities were mild; the most common grades 3 and 4 toxicities were anaemia (5.6%), neutropenia (4.8%) and vomiting (5.6%). Other grades 3 and 4 non-haematological toxicities included diarrhoea (3.2%), neurotoxicity (0.8%), asthenia (0.8%) and phlebitis (0.8%). CONCLUSION: Combination chemotherapy with cisplatin and 2 consecutive weekly infusions of docetaxel can be considered an active and well-tolerated regimen with a good response rate and less toxicity for patients with advanced non-small cell lung cancers.

EBV-associated diffuse large B-cell lymphoma in a psoriatic treated with methotrexate.

Methotrexate-associated lymphoproliferative disorder (MTX-LPD) is a lymphoid proliferation or lymphoma in a patient immunosuppressed with MTX, which is usually administered for treating autoimmune diseases. The majority of MTX-LPD cases develop in patients with rheumatoid arthritis and occasionally with psoriasis who had been treated with MTX. Here, we report on a 50-year-old Taiwanese male with severe psoriasis, who received high doses of MTX. The patient developed EBV-positive MTX-LPD at nodal and extranodal sites. The diffuse and polymorphic lymphoid infiltrate consisted predominantly of immunoblasts and plasmablasts expressing B-cell markers, CD138, Epstein-Barr virus (EBV)-LMP1, and EBNA2, and these were monotypic for kappa light chain. The tumor cells were also positive for EBV by in situ hybridization. These findings indicated a type III latency infection of EBV. The patient died of progressive disease after 19 months. A review of the previously reported cases shows that MTX-LPD, in association with psoriasis, occurs in middle-aged males. The tumors are diffuse large B-cell lymphomas with immunoblastic morphology, and frequently show plasmacytic differentiation.

Retrospectively comparative evaluation of the first- and second-line chemotherapy with campto and oxaliplatin combined with oral tegafur/uracil (UFT)/leucovorin (LV) in patients with metastatic colorectal cancer.

Oral tegafur/uracil (UFT), like an intravenous drip with 5-fluorouracil (5-FU)/leucovorin (LV), has been regarded as an active regimen in the treatment of advanced colorectal cancer. In this clinical trial, we evaluate the toxicity and efficacy of regimens containing oral UFT/LV, instead of an intravenous drip with 5-FU/LV, in the treatment of metastatic colorectal cancer. A phase II study involving 39 patients with metastatic colorectal cancer (CRC) who received UFT/LV plus irinotecan (Group A)/oxaliplatin (Group B) alternated with UFT/LV plus oxaliplatin (Group A)/irinotecan (Group B) was evaluated. The overall tumor control rate (CR + PR + SD) was approximately 64%, and median overall survival was approximately 12 months. Of the 547 doses the 39 patients received, 6 events (1.10%) of neutropenia, 5 events (0.91%) of diarrhea, 2 events (0.37%) of stomatitis, and 2 events (0.37%) of anemia were observed. The alternating regimen seems to be effective and well tolerated for patients with metastatic CRC.

Metastatic carcinoma of the breast: a case with the unusual presentation of unilateral periorbital edema.

BACKGROUND: Metastasis of mammary cancer involving the orbit is common, and it typically presents with enophthalmos and restrictions of ocular motility. We report a case of mammary cancer with the unusual presentation of unilateral periorbital edema only. The possible mechanisms of unilateral periorbital swelling are discussed. CASE: Metastasis of breast cancer involving unilateral eyelid edema was diagnosed in a 66-year-old woman. A biopsy was performed to confirm the etiology after vague neuroimaging findings. The diagnosis was based on the histopathologic features of carcinomatous cells in the excised specimen. OBSERVATIONS: Insidious, progressive unilateral upper and lower eyelid swelling of the right eye disappeared after one cycle of palliative chemotherapy. Neither restriction nor proptosis developed in the whole course. CONCLUSIONS: Possible metastasis should be considered as a possible etiology of unilateral eyelid edema, even without a palpable mass or limitation of ocular motility. A biopsy should be performed in cases of unexplained eyelid edema.