Adjuvant role of a T-type calcium channel blocker, TTA-A2, in lung cancer treatment with paclitaxel

Dysregulation of calcium homeostasis in cancer and its role in chemoresistance

Globally, cancer, as a major public health concern, poses a severe threat to people's well-being. Advanced and specialized therapies can now cure the majority of people with early-stage cancer. However, emerging resistance to traditional and novel chemotherapeutic drugs remains a serious issue in clinical medicine. Chemoresistance often leads to cancer recurrence, metastasis, and increased mortality, accounting for 90% of chemotherapy failures. Thus, it is important to understand the molecular mechanisms of chemoresistance and find novel therapeutic approaches for cancer treatment. Among the several factors responsible for chemoresistance, calcium (Ca2+) dysregulation plays a significant role in cancer progression and chemoresistance. Therefore, targeting this derailed Ca2+ signalling for cancer therapy has become an emerging research area. Of note, the Ca2+ signal and its proteins are a multifaceted and potent tool by which cells achieve specific outcomes. Depending on cell survival needs, Ca2+ is either upregulated or downregulated in both chemosensitive and chemoresistant cancer cells. Consequently, the appropriate treatment should be selected based on Ca2+ signalling dysregulation. This review discusses the role of Ca2+ in cancer cells and the targeting of Ca2+ channels, pumps, and exchangers. Furthermore, we have emphasised the role of Ca2+ in chemoresistance and therapeutic strategies. In conclusion, targeting Ca2+ signalling is a multifaceted process. Methods such as site-specific drug delivery, target-based drug-designing, and targeting two or more Ca2+ proteins simultaneously may be explored; however, further clinical studies are essential to validate Ca2+ blockers' anti-cancer efficacy.

T-Type Calcium Channels: A Mixed Blessing

The role of T-type calcium channels is well established in excitable cells, where they preside over action potential generation, automaticity, and firing. They also contribute to intracellular calcium signaling, cell cycle progression, and cell fate; and, in this sense, they emerge as key regulators also in non-excitable cells. In particular, their expression may be considered a prognostic factor in cancer. Almost all cancer cells express T-type calcium channels to the point that it has been considered a pharmacological target; but, as the drugs used to reduce their expression are not completely selective, several complications develop, especially within the heart. T-type calcium channels are also involved in a specific side effect of several anticancer agents, that act on microtubule transport, increase the expression of the channel, and, thus, the excitability of sensory neurons, and make the patient more sensitive to pain. This review puts into context the relevance of T-type calcium channels in cancer and in chemotherapy side effects, considering also the cardiotoxicity induced by new classes of antineoplastic molecules.

Detection of CEA and ProGRP Levels in BALF of Patients with Peripheral Lung Cancer and Their Relationship with CT Signs

Background

Lung cancer is a common clinical thoracic malignant tumor, which had a serious impact on the safety of patients, currently ranking first in all malignant tumors in morbidity and mortality, with generally less than 5% survival rate in 5 years.

Objective

To investigate the relationship and significance between carcinoembryonic antigen (CEA) and precursor gastrin-releasing peptide (ProGRP) changing levels in bronchoalveolar lavage fluid (BALF) and CT imaging features in patients with peripheral lung cancer.

Methods

A total of 90 patients diagnosed with peripheral lung cancer as the lung cancer group and 60 patients with benign lung diseases as the control group in our hospital from May 2019 to October 2021 were selected to compare the differences of CEA and ProGRP in BALF by the classification of CT features.

Results

The levels of CEA and ProGRP in the BALF of the lung cancer group were significantly higher than those of the control group; the proportion of patients with lobulation sign, burr sign, ground glass sign, pleural effusion, and lesion diameter ≥ 3.0 cm in the lung cancer group was higher than that in the control group; the CEA level in BALF of lung cancer patients with spicule sign, pleural effusion, and lesion diameter ≥ 3.0 cm was significantly higher than that without these symptoms, while ProGRP level in the BALF of lung cancer patients with lobulation sign, burr sign, ground glass sign, pleural effusion, and lesion diameter ≥ 3.0 cm was significantly higher than that of lung cancer patients without these symptoms.

Conclusion

The check of CEA and ProGRP in BALF in combination with CT features has a certain clinical value for the diagnosis of lung cancer. At the same time, the increased levels of CEA and ProGRP in BALF have a certain correlation with the changes of malignant signs of lung cancer in CT examination.